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Inhalation

Inhalation of hydrogen gas: breathing a low-concentration H₂ (often H₂/O₂) mixture, typically through a nasal cannula. Concentration and duration vary considerably from study to study.

Human studies on molecular hydrogen given by Inhalation. This page collects the 248 studies using this route — 14 randomized trials, 31 pilot/observational studies and 62 reviews. Listed newest first.

2026 · Seneff — The essential role of hydrogen gas recycling by gut microbes in reducing deuterium load in host mitochondria: is trimethylamine oxide a deuterium sensor?

Metabolomics : Official journal of the Metabolomic Society

This hypothesis paper proposes that the gut microbiome's recycling of molecular hydrogen plays a role in keeping mitochondria supplied with deuterium-depleted water — and that TMAO (a gut-derived metabolite elevated in many chronic diseases) may function as a marker for impaired deuterium management.

2026 · Nguyen Puente — Emerging Clinical Applications for Molecular Hydrogen

Respiratory care

Inhaled molecular hydrogen (H₂) has accumulated a growing body of encouraging clinical findings across neurological, cardiovascular, oncological and respiratory conditions — yet the evidence base remains constrained by small study sizes, inconsistent methodology, and a lack of standardised delivery systems.

2026 · Merigo — Gas Therapies for Neuro-Protection

Critical care clinics

Cardiac arrest causes severe neurological damage, and conventional treatment options remain inadequate — but inhaled gas therapies including molecular hydrogen (H₂), nitric oxide, xenon and argon show neuroprotective promise through antioxidant, anti-inflammatory and anti-apoptotic mechanisms.

2026 · Nguyen — Advances in hydrogen delivery strategies for therapeutic applications

Advanced drug delivery reviews

Molecular hydrogen (H₂) has selective antioxidant, anti-inflammatory and anticancer properties — but getting it reliably to target tissues remains the central challenge limiting clinical use.

2026 · Pan — Stimuli-Responsive Hydrogen Production from Nanomaterials: Design, Regulation and Biomedical Applications

Advanced healthcare materials

H₂ gas has broad therapeutic potential, but its low solubility and lack of targeted delivery limit clinical use — nanotechnology offers a solution through stimuli-responsive nanomaterials that produce H₂ on demand at disease sites.

2025 · Li — Application Trends of Hydrogen-generating Nanomaterials for the Treatment of ROS-related Diseases

Biomaterials science

Hydrogen-producing nanomaterials allow targeted, sustained delivery of H₂ directly to sites of disease — this review surveys how combining H₂ gas therapy with nanomedicine advances treatment of cancers, neurodegeneration, cardiovascular, liver, kidney, and skin diseases driven by excess reactive oxygen species (ROS).

2024 · Xu — The Landscape of Smart Biomaterial-Based Hydrogen Therapy

Advanced science (Weinheim, Baden-Wurttemberg, Germany)

This comprehensive review maps the rapidly evolving field of biomaterial-based H₂ delivery systems — engineered materials that can carry, target, and release molecular hydrogen precisely where disease processes occur.

2024 · Tsuzuki — Idiopathic Sudden Sensorineural Hearing Loss: A Review Focused on the Contribution of Vascular Pathologies

Auris, nasus, larynx

Idiopathic sudden sensorineural hearing loss (ISSNHL) — an abrupt hearing loss of unknown cause, sometimes with vertigo — is believed to be primarily driven by vascular impairment of the inner ear, including cochlear ischemia and infarction.

2024 · Afkhami — Exploring Approaches to Pulp Vitality Assessment: A Scoping Review of Nontraditional Methods

International endodontic journal

Accurate assessment of dental pulp vitality is critical in endodontics — yet current clinical tests are imprecise.

2024 · Khan — Catalytic innovations: Improving wastewater treatment and hydrogen generation technologies.

Journal of environmental management

Nanomaterials as catalysts can both clean wastewater of toxic organic pollutants and simultaneously generate hydrogen gas — a dual benefit reviewed here.

2024 · James et al. — The Synergistic Potential of Hydrogen Inhalation and Hyperbaric Oxygen Therapy

Journal of vascular surgery

This review article in the Journal of Vascular Surgery examines whether combining hydrogen inhalation with hyperbaric oxygen therapy (HBOT) could produce synergistic therapeutic benefits.

2024 · Takefuji — Hydrogen Inhalation Therapy for Inflammation and Eye Diseases: A Review of the Literature

Eye (London, England)

This literature review in the journal Eye surveys published evidence on hydrogen inhalation therapy for inflammatory conditions — with a focus on eye diseases.

2023 · Kuo — Molecular Hydrogen: Emerging Treatment for Stroke Management

Chemical Research in Toxicology

Molecular hydrogen (H₂) is an emerging therapeutic approach in ischemic stroke — antioxidative, anti-inflammatory and anti-apoptotic.

2023 · Johnsen et al. — Molecular Hydrogen Therapy — A Review on Clinical Studies and Outcomes

Molecules (Basel, Switzerland)

This comprehensive review in Molecules analysed 81 identified clinical trials and 64 scientific publications on human studies of molecular hydrogen (H₂) therapy across a broad range of disease areas.

2023 · Saengsin et al. — Hydrogen Therapy as a Potential Therapeutic Intervention in Heart Disease: From the Past Evidence to Future Application

Cellular and molecular life sciences : CMLS

This comprehensive review in Cellular and Molecular Life Sciences synthesises in-vitro, animal, and clinical evidence for molecular hydrogen's protective effects in cardiovascular disease, covering its antioxidant, anti-inflammatory, and anti-apoptotic mechanisms.

2023 · Li — Trend of research on the medical use of molecular hydrogen: a bibliometric analysis

Medical gas research

This bibliometric analysis of 1,126 PubMed publications on molecular hydrogen therapy (up to July 2021) shows a clear upward trend from 2007 onward.

2022 · Biswas — Electrocoagulation and electrooxidation technologies for pesticide removal from water or wastewater: A review

Chemosphere

This review covers electrochemical methods — electrocoagulation and electrooxidation — for removing pesticides from water, and notes that H₂ gas is generated as a byproduct at the cathode during electrocoagulation.

2021 · Noda — Neuroprotective and Preventative Effects of Molecular Hydrogen

Current Pharmaceutical Design

Hydrogen (H₂) is neuroprotective: this review summarizes how daily H₂ could slow the progression of neurodegenerative diseases such as Parkinson's and Alzheimer's (for which there are still no specific drugs) — via antioxidant and anti-inflammatory effects and via a surprising stomach-brain connection.

2021 · Bragina — Intestinal microbiota of athletes.

Voprosy pitaniia

This systematic review of 14 studies finds that athletes harbour a more diverse gut microbiome than sedentary individuals, with higher proportions of bacteria that ferment complex carbohydrates into short-chain fatty acids — including species that use hydrogen gas (H₂) and formate to drive fermentation.

2021 · Quan — Protective effects of molecular hydrogen on lung injury from lung transplantation.

Experimental biology and medicine (Maywood, N.J.)

This review synthesizes the experimental evidence showing that H₂ — administered via inhalation, drinking, injection, or topical bath — can reduce the oxidative stress and inflammation responsible for primary graft dysfunction after lung transplantation.

2021 · Magliocca et al. — Inhaled gases as novel neuroprotective therapies in the postcardiac arrest period.

Current opinion in critical care

After cardiac arrest, inhaled gases such as xenon, argon, nitric oxide, and molecular hydrogen (H₂) have shown neuroprotective properties in experimental models.

2021 · Chen et al. — Chemical and Biochemical Aspects of Molecular Hydrogen in Treating Kawasaki Disease and COVID-19.

Chemical research in toxicology

Kawasaki disease and COVID-19 both involve damaging vascular inflammation; this review explores the chemical and biochemical rationale for using inhaled molecular hydrogen (H₂) in both conditions.

2021 · Zhang et al. — Hydrogen Gas: A Novel Type of Antioxidant in Modulating Sexual Organs Homeostasis.

Oxidative medicine and cellular longevity

Molecular hydrogen (H₂) appears to benefit reproductive health in both males and females — from improving sperm motility and erectile function to protecting ovarian function and reducing uterine inflammation — acting primarily through antioxidant and anti-inflammatory mechanisms.

2021 · Sano et al. — Hydrogen Gas Therapy: From Preclinical Studies to Clinical Trials.

Current pharmaceutical design

Hydrogen gas (H₂) has demonstrated broad therapeutic potential in preclinical and early clinical studies — from ischaemia-reperfusion injury to organ transplantation and emergency medicine — and appears safe, inexpensive, and easy to administer.

2021 · Li et al. — Hydrogen Commonly Applicable from Medicine to Agriculture: From Molecular Mechanisms to the Field.

Current pharmaceutical design

Beyond its medical applications, molecular hydrogen (H₂) shows substantial promise in agriculture — enhancing plant stress tolerance, improving crop quality and yield, prolonging shelf life, and even strengthening livestock resilience.

2021 · Htun et al. — Hydrogen and Therapeutic Gases for Neonatal Hypoxic-Ischemic Encephalopathy: Potential Neuroprotective Adjuncts in Translational Research

Pediatric research

Neonatal hypoxic-ischemic encephalopathy (HIE) — brain injury in newborns caused by oxygen deprivation — remains without a fully effective treatment, and molecular hydrogen has emerged as a promising neuroprotective candidate.

2021 · Ostojic — Hydrogen as a Potential Therapeutic in Obesity: Targeting the Brain

Trends in endocrinology and metabolism: TEM

This short review considers whether molecular H₂ could act directly on brain structures involved in obesity regulation — particularly the hypothalamus.

2021 · Ostojic — Hydrogen Gas as an Exotic Performance-Enhancing Agent: Challenges and Opportunities

Current pharmaceutical design

This review maps approximately two dozen studies on hydrogen (H₂) and exercise performance, finding promising ergogenic signals — but also highlighting the absence of a gold-standard protocol.

2020 · Hirano et al. — A „philosophical molecule,” hydrogen may overcome senescence and intractable diseases

Medical gas research

This short review argues that molecular hydrogen (H₂) is uniquely positioned to combat ageing and difficult-to-treat diseases by scavenging hydroxyl radicals (·OH) — the most damaging reactive oxygen species — which are predominantly generated in the mitochondria.

2020 · Chen et al. — The future of cryoablation: An abscopal effect

Cryobiology

This review on cryoablation for cancer treatment briefly mentions molecular hydrogen (H₂) as a potential combination partner — specifically because H₂ may rescue exhausted CD8+ T cells and thereby amplify the immune response triggered by tumour ablation.

2020 · Kawamura et al. — Application of Molecular Hydrogen as a Novel Antioxidant in Sports Science

Oxidative medicine and cellular longevity

This review surveys the evidence on molecular hydrogen (H₂) intake and exercise, covering all administration routes and focusing on exercise-induced oxidative stress.

2019 · Zhou — Micro/Nanomaterials-Augmented Hydrogen Therapy

Advanced Healthcare Materials

Nanomedicine for hydrogen: H₂ works in oxidative-inflammatory diseases, but diffuses without direction and dissolves poorly in water.

2019 · Qian — Medical Application of Hydrogen in Hematological Diseases.

Oxidative medicine and cellular longevity

This review article surveys the clinical and basic research on molecular hydrogen in haematological diseases, including graft-versus-host disease (GvHD) after stem cell transplantation, and summarises H₂'s established antioxidant, anti-inflammatory, and anti-apoptotic properties.

2019 · LeBaron et al. — A New Approach for the Prevention and Treatment of Cardiovascular Disorders. Molecular Hydrogen Significantly Reduces the Effects of Oxidative Stress.

Molecules (Basel, Switzerland)

Molecular hydrogen (H₂) has been studied in preclinical and clinical settings for a wide range of cardiovascular conditions linked to oxidative stress and inflammation.

2019 · LeBaron et al. — Hydrogen gas: from clinical medicine to an emerging ergogenic molecule for sports athletes.

Canadian journal of physiology and pharmacology

Hydrogen gas (H₂) may serve as both an exercise mimetic and a „redox adaptogen“ — reducing harm from excessive or damaging exercise while potentially amplifying the benefits of healthy training.

2019 · Li et al. — Hydrogen as a complementary therapy against ischemic stroke: A review of the evidence.

Journal of the neurological sciences

Hydrogen gas inhalation has been studied as a complementary treatment for ischemic stroke, targeting the damaging cascade of free radicals and inflammation that unfolds after a blood vessel in the brain is blocked.

2019 · Wu — Hydrogen Gas from Inflammation Treatment to Cancer Therapy

ACS nano

This review surveys the emerging field of molecular hydrogen (H₂) therapy, from its anti-inflammatory mechanisms to its potential role in cancer treatment, with special focus on how nanomaterials can deliver H₂ more precisely to target sites.

2018 · Hylemon — Metabolism of hydrogen gases and bile acids in the gut microbiome

FEBS letters

This review examines how gut bacteria produce and consume molecular hydrogen (H₂) during fermentation, and how these processes interact with bile acid metabolism.

2017 · Iketani — Molecular Hydrogen as a Neuroprotective Agent

Current Neuropharmacology

Molecular hydrogen (H₂) acts as an antioxidant and anti-inflammatory agent and shows potential in neurological disorders — from stroke through neurodegenerative diseases to brain damage in newborns.

2015 · Ohta — Molecular hydrogen as a novel antioxidant: overview of the advantages of hydrogen for medical applications.

Methods in enzymology

Molecular hydrogen (H₂) is a mild, selective antioxidant that neutralizes the most damaging reactive oxygen species without disrupting normal cellular redox signaling — a key advantage over broad-spectrum antioxidants.

2015 · Shimura et al. — Radiation occupational health interventions offered to radiation workers in response to the complex catastrophic disaster at the Fukushima Daiichi Nuclear Power Plant.

Journal of radiation research

Following the 2011 Fukushima nuclear disaster, a comprehensive set of occupational health measures protected emergency workers from radiation overexposure — fewer than 1% received doses above 100 mSv, and no deaths from radiation were reported.

2015 · Torzillo et al. — Advances in the biotechnology of hydrogen production with the microalga Chlamydomonas reinhardtii.

Critical reviews in biotechnology

The green microalga Chlamydomonas reinhardtii can produce hydrogen gas from sunlight and water — a clean energy prospect, but one still far from industrial viability.

2015 · Osonoi — [Alpha-glucosidase inhibitor]. (Nihon Rinsho)

Nihon rinsho. Japanese journal of clinical medicine

This Japanese-language clinical review discusses alpha-glucosidase inhibitors (α-GI) — a class of oral antidiabetic drugs — noting that their characteristic intestinal side effects (gas, bloating) arise from hydrogen gas produced by gut bacteria fermenting undigested carbohydrates.

2014 · Xie et al. — Hydrogen gas presents a promising therapeutic strategy for sepsis.

BioMed research international

This review summarises preclinical evidence that inhaled molecular hydrogen (H₂) improved survival and reduced organ damage in animal models of sepsis.

2014 · Ohta — Molecular hydrogen as a preventive and therapeutic medical gas: initiation, development and potential of hydrogen medicine.

Pharmacology & therapeutics

One of the founding papers of hydrogen medicine, authored by Shigeo Ohta, summarises how H₂ was discovered to react with harmful hydroxyl radicals in cells — and why this makes it a candidate for preventing and treating a wide range of diseases.

2013 · Zheng — Equol: a metabolite of soy isoflavones by intestinal microflora — a review

Wei sheng wu xue bao = Acta microbiologica Sinica

Equol, a metabolite of the soy isoflavone daidzein produced by gut bacteria, may explain the health benefits of soy — but only 33–50 % of humans can produce it.

2013 · Lucas — Role of the Toll Like receptor (TLR) radical cycle in chronic inflammation: possible treatments targeting the TLR4 pathway

Molecular neurobiology

Activation of the Toll-like receptor 4 (TLR4) pathway — triggered by environmental factors such as ozone, particulate matter, ionizing radiation, and LPS from bacteria — may underlie a wide spectrum of chronic inflammatory and neuropsychiatric diseases.

2012 · Ohta — Molecular hydrogen is a novel antioxidant to efficiently reduce oxidative stress with potential for the improvement of mitochondrial diseases.

Biochimica et biophysica acta

This review by Shigeo Ohta — one of the founders of modern H₂ medicine — surveys the biological effects of molecular hydrogen across more than 38 diseases, physiological states, and clinical tests documented in the years following the 2007 Nature Medicine paper.

2012 · Nie et al. — Hydrogenase: the next antibiotic target?

Clinical science (London, England : 1979)

Bacteria produce hydrogen gas (H₂) via enzymes called hydrogenases — and this review proposes that these enzymes, by generating H₂ which neutralizes bactericidal hydroxyl radicals, may actually help bacteria survive antibiotic treatment and evade immune defenses.

2011 · Ohta — Recent progress toward hydrogen medicine: potential of molecular hydrogen for preventive and therapeutic applications.

Current pharmaceutical design

Since the landmark 2007 Nature Medicine paper demonstrating that molecular hydrogen (H₂) selectively neutralizes toxic hydroxyl radicals, the field of hydrogen medicine has grown rapidly.

2011 · Zheng et al. — Hydrogen resuscitation, a new cytoprotective approach.

Clinical and experimental pharmacology & physiology

Oxidative injury — from ischemia-reperfusion, inflammation, trauma, or toxins — damages cells, tissues, and organs by unleashing reactive oxygen species.

2010 · Shen — Hydrogen as a novel and effective treatment of acute carbon monoxide poisoning.

Medical hypotheses

This hypothesis paper proposes that inhaled molecular hydrogen (H₂) could be an effective treatment for acute carbon monoxide (CO) poisoning.

2009 · Mahlen — Oral abscess caused by Campylobacter rectus: case report and literature review.

Journal of clinical microbiology

This case report and literature review describes the first documented case of a palate abscess caused by Campylobacter rectus in a patient with gastroesophageal adenocarcinoma.

2004 · Züttel — Hydrogen storage methods

Die Naturwissenschaften

This theoretical engineering review surveys six methods for storing hydrogen gas — from high-pressure cylinders and liquid H₂ cryotanks to metal hydrides — and assesses their volumetric density, gravimetric performance, and practical limitations for energy applications.

1999 · Särnblad — Lactose intolerance in children. An analysis of hydrogen gas in exhaled air simplifies and improves diagnosis.

Lakartidningen

This review article, published in the Swedish medical journal Läkartidningen, discusses the hydrogen breath test as a diagnostic tool for lactose intolerance in children.

1998 · Swart — ¹³C breath test in gastroenterological practice.

Scandinavian journal of gastroenterology. Supplement

This review summarises the use of breath tests — including both hydrogen gas excretion and ¹³C-labelled carbon dioxide — in gastroenterological practice as non-invasive alternatives to invasive diagnostic procedures.

1994 · Beglinger — Breath Tests: A Clarification of the Topic

Bildgebung = Imaging

Breath tests measuring either hydrogen gas (H₂) or labeled carbon dioxide (¹³CO₂) in exhaled air represent a non-invasive diagnostic class for gastroenterological evaluation — this review clarifies their main indications and limitations.

1988 · Scrimshaw — The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance.

The American journal of clinical nutrition

Most humans lose the ability to digest lactose after infancy — and a standard lactose tolerance test is a poor predictor of whether an individual can actually consume moderate amounts of milk without symptoms.

1988 · Holm — Role of blood flow in gastric acid secretion.

The American journal of physiology

The relationship between blood flow and gastric acid secretion is more complex than long assumed: most measurement methods show no simple proportional link, but there is a critical minimum blood flow below which both oxygen use and acid secretion fall together.

1983 · Ostrander — Breath hydrogen analysis: a review of the methodologies and clinical applications.

Journal of pediatric gastroenterology and nutrition

Hydrogen gas exhaled in breath — produced when gut bacteria ferment unabsorbed carbohydrates — can serve as a non-invasive clinical tool to detect carbohydrate malabsorption in adults and older children.

2026 · Grepl — Sixty-minute inhalation of molecular hydrogen decreases blood oxygen saturation but does not alter autonomic cardiac regulation at rest in healthy females: a randomized, double-blind, placebo-controlled crossover study

Canadian Journal of Physiology and Pharmacology

One hour of H₂ inhalation at rest lowers blood oxygen saturation minimally (95.9% vs. 96.7%, p ≤ 0.007) without altering autonomic cardiac regulation.

2024 · Dong — Inhalation of Hydrogen-Rich Gas before Acute Exercise Alleviates Exercise Fatigue: A Randomized Crossover Study

International journal of sports medicine

Pre-exercise inhalation of hydrogen-rich gas (HRG) reduced subjective fatigue, improved cycling performance during the final phase of exhaustion trials, and lowered post-exercise lactate and oxidative stress markers in healthy men — compared to placebo air inhalation.

2023 · Deryugina — Molecular hydrogen exposure improves functional state of red blood cells in the early postoperative period: a randomized clinical study

Medical Gas Research

Hydrogen inhalation during cardiac surgery with a heart-lung machine improves the state of red blood cells and the postoperative course.

2023 · Lin — Hydrogen Gas Treatment Improves Postoperative Delirium and Cognitive Dysfunction in Elderly Noncardiac Patients

Journal of Personalized Medicine

Prophylactic hydrogen inhalation nearly halves postoperative delirium in elderly patients.

2022 · Tao — A randomized, placebo-controlled clinical trial of hydrogen/oxygen inhalation for non-alcoholic fatty liver disease

Journal of Cellular and Molecular Medicine

Hydrogen/oxygen inhalation improves blood lipid and liver values in non-alcoholic fatty liver — and measurably lowers liver fat content in moderate-to-severe cases.

2020 · Shibayama — Impact of hydrogen-rich gas mixture inhalation through nasal cannula during post-exercise recovery period on subsequent oxidative stress, muscle damage, and exercise performances in men

Medical Gas Research

Inhaling hydrogen gas right after intense exercise lowered a DNA oxidation marker and protected jump strength from the exercise-induced drop. Other performance and blood markers, however, remained unchanged.

2017 · Tamura — Efficacy of Inhaled Hydrogen on Neurological Outcome Following Brain Ischemia During Post-Cardiac Arrest Care (HYBRID II Trial): Study Protocol for a Randomized Controlled Trial

Trials

This is the published protocol for the HYBRID II trial — a multicenter, randomized, double-blind, placebo-controlled trial designed to enroll 360 comatose cardiac arrest survivors and evaluate whether 18 hours of 2% hydrogen inhalation improves 90-day neurological outcome.

2017 · Ono et al. — Hydrogen Gas Inhalation Treatment in Acute Cerebral Infarction: A Randomized Controlled Clinical Study on Safety and Neuroprotection.

Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association

In this randomized controlled trial with 50 stroke patients, inhaling 3% H₂ gas twice daily for 7 days was safe and led to measurable improvements in MRI lesion intensity, stroke severity scores (NIHSS), and functional independence (Barthel Index).

2016 · Gong et al. — Protective effect of hydrogen on the lung of sanitation workers exposed to haze.

Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory diseases

2026 · Pozdnyakova — The combined use of inhaled nitric oxide and molecular hydrogen in patients with post-COVID-19 syndrome

Terapevticheskii arkhiv

Combined inhalation of nitric oxide (NO) and molecular hydrogen (H₂) relieves post-COVID syndrome better than NO alone.

2025 · Moriya et al. — Hydrogen Inhalation Is Associated With a Transient Rightward Shift in Prefrontal Oxyhemoglobin Asymmetry and Autonomic Modulation

Scientific reports

A single 30-minute session of pure hydrogen gas inhalation (99.9 % H₂, 300 mL/min via nasal cannula) transiently increased oxygenation in the right prefrontal cortex and simultaneously altered heart-rate variability in healthy adults — findings consistent with a brief, coordinated neurovascular-autonomic response.

2025 · Habet et al. — Hydrogen-FAST: Study Protocol for Inhaled Hydrogen Gas as Adjunctive Therapy in Refractory Cardiac Arrest (ECPR)

Trials

The Hydrogen-FAST trial is a phase 1 multicenter randomised controlled trial investigating whether inhaled 2 % hydrogen gas, delivered continuously for 72 hours during extracorporeal cardiopulmonary resuscitation (ECPR), is feasible and safe in patients with refractory cardiac arrest and underlying heart disease.

2024 · Dong — Hydrogen-Rich Gas Enhanced Sprint-Interval Performance: Metabolomic Insights into Underlying Mechanisms

Nutrients

Inhaling hydrogen-rich gas (HRG) for 60 minutes before a sprint-interval test improved late-stage anaerobic performance and reduced performance decline across sprints in healthy men.

2024 · Pozdnyakova — Rehabilitation program of post-COVID-19 syndrome with the use of nitric oxide and molecular hydrogen

Terapevticheskii Arkhiv

The combined inhalation of nitric oxide and hydrogen improved complaints in post-COVID syndrome.

2024 · Mu — Hydrogen regulated pyroptosis through NLRP3-GSDMD pathway to improve airway mucosal oxidative stress injury induced by endotracheal tube cuff compression.

Free radical biology & medicine

Endotracheal tube cuffs compress airway tissue during anaesthesia, triggering oxidative stress and a form of inflammatory cell death (pyroptosis) — and hydrogen inhalation or hydrogen-rich saline in the cuff significantly reduced this damage.

2024 · Ichikawa — Realizing brain therapy with „smart medicine“: mechanism and case report of molecular hydrogen inhalation for Parkinson's disease.

Medical gas research

A case report describes symptomatic improvement in a Parkinson's disease patient — including reduced body bending and hand tremor — following hydrogen inhalation, alongside a mechanistic argument that H₂ can enter the brain and neutralise the hydroxyl radicals that oxidise dopamine in the midbrain.

2024 · Lin — Early Hydrogen-Oxygen Gas Mixture Inhalation in Patients with Aneurysmal Subarachnoid Hemorrhage (HOMA): study protocol for a randomized controlled trial.

Trials

This is the published protocol for the first large-scale randomised controlled trial of hydrogen therapy in aneurysmal subarachnoid haemorrhage (aSAH): 206 patients will inhale a 67% hydrogen / 33% oxygen gas mixture for 8 hours daily in the ICU, targeting delayed cerebral ischaemia and cerebral vasospasm.

2024 · Liu — The Benefit of Hydrogen Gas as an Adjunctive Therapy for Chronic Obstructive Pulmonary Disease.

Medicina (Kaunas, Lithuania)

Six COPD patients who added hydrogen gas inhalation (30 min, three times daily for 30 days) to standard treatment showed significant improvements in symptom burden scores (CAT) and dyspnoea scale (mMRC) — but no changes in lung function, sleep quality, inflammation markers, or oxidative stress markers.

2024 · Hirano — Successful treatment of myalgic encephalomyelitis/chronic fatigue syndrome using hydrogen gas: four case reports.

Medical gas research

Four patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) — one of medicine's most intractable and poorly understood conditions — are reported to have improved with hydrogen gas inhalation therapy.

2023 · Wang — Effects of molecular hydrogen intervention on the gut microbiome in methamphetamine abusers with mental disorder.

Brain research bulletin

In female methamphetamine users suffering from depression and anxiety, both drinking and inhaling molecular hydrogen significantly alleviated mental health symptoms — and hydrogen inhalation also shifted gut microbiome composition.

2022 · Zhao — Effectiveness and safety of hydrogen inhalation as an adjunct treatment in Chinese type 2 diabetes patients: A retrospective, observational, double-arm, real-life clinical study

Frontiers in Endocrinology

Hydrogen inhalation as an adjunct improved blood sugar control in type 2 diabetes. In a large real-life study (n = 1,088), over 6 months the H₂ group lowered long-term blood sugar HbA1c more (−0.94% vs.

2022 · Deryugina — Dynamics of Metabolic and Oxidative Parameters of Erythrocytes during Treatment of Chronic Heart Failure with Molecular Hydrogen.

Bulletin of experimental biology and medicine

In patients with chronic heart failure, inhaling 2% molecular hydrogen — either once or repeatedly over five days — improved red blood cell energy metabolism, reduced oxidative stress markers, and enhanced antioxidant enzyme activity.

2021 · Kaibori — Effect of hydrogen gas inhalation on patient QOL after hepatectomy: protocol for a randomised controlled trial

Trials

This is a published trial protocol — not yet results — for a randomised, double-blind, controlled study testing whether inhaling hydrogen gas after liver surgery improves patients' quality of life and reduces post-operative complications.

2021 · Danilova — Application of Molecular Hydrogen in Heart Surgery under Cardiopulmonary Bypass

Sovremennye tekhnologii v meditsine

During open-heart surgery on cardiopulmonary bypass, inhaling 1.5–2% hydrogen gas during anaesthesia reduced markers of lipid peroxidation (oxidative stress) compared to patients who did not receive H₂.

2021 · Chen — High-flow hydrogen inhalation might suppress the immune function of middle-aged participants: a self-controlled study

Medical gas research

Twenty healthy adults who inhaled hydrogen at high flow rates for 2–4 hours daily over two weeks showed significant decreases in several immune cell populations, including T helper cells, NK cells, and gamma delta T cells.

2020 · Hori et al. — Inhalation of molecular hydrogen increases breath acetone excretion during submaximal exercise: a randomized, single-blinded, placebo-controlled study.

Medical gas research

Inhaling 1 % H₂ gas during moderate-intensity cycling significantly increased breath acetone levels and oxygen uptake in ten healthy men — suggesting that H₂ promotes hepatic lipid metabolism during aerobic exercise.

2020 · Wang et al. — Hydrogen gas (XEN) inhalation ameliorates airway inflammation in asthma and COPD patients.

QJM : monthly journal of the Association of Physicians

A single 45-minute inhalation of hydrogen-containing steam (2.4 % H₂) reduced key inflammatory cytokines in airways of 10 asthma and 10 COPD patients — including monocyte chemotactic protein 1 in both groups and IL-8 in asthma.

2018 · Akagi — Immunological Effect of Hydrogen Gas: Hydrogen Gas Improves Clinical Outcomes of Cancer Patients

Gan to kagaku ryoho. Cancer & chemotherapy

In a cohort of 55 Stage IV colorectal cancer patients, hydrogen gas inhalation reduced the proportion of exhausted immune cells (terminal PD-1⁺ CD8⁺ T cells) in 63.6% of patients, and patients who combined H₂ inhalation with nivolumab immunotherapy showed significantly longer overall survival than nivolumab alone.

2017 · Katsumata et al. — The Effects of Hydrogen Gas Inhalation on Adverse Left Ventricular Remodeling After Percutaneous Coronary Intervention for ST-Elevated Myocardial Infarction — First Pilot Study in Humans.

Circulation journal : official journal of the Japanese Circulation Society

In this first-in-human pilot study with 20 STEMI patients undergoing PCI, inhaling 1.3% H₂ gas during and after the procedure was safe and showed a numerical trend toward better left ventricular recovery at 6 months — but the primary endpoint (cardiac salvage index at 7 days) did not reach statistical significance.

2016 · Tamura et al. — Feasibility and Safety of Hydrogen Gas Inhalation for Post-Cardiac Arrest Syndrome — First-in-Human Pilot Study.

Circulation journal : official journal of the Japanese Circulation Society

In this first-in-human pilot study, 5 out-of-hospital cardiac arrest patients who achieved spontaneous circulation received H₂ gas inhalation combined with standard temperature management — no adverse effects were observed, and 4 of 5 patients survived 90 days with favorable neurological outcomes.

2015 · Ishibashi et al. — Improvement of psoriasis-associated arthritis and skin lesions by treatment with molecular hydrogen: A report of three cases.

Molecular medicine reports

In three patients with psoriasis-associated arthritis and skin lesions, H₂ treatment (via saline infusion, inhalation, and/or high-concentration drinking water) reduced DAS28 and PASI scores, caused near-complete clearing of skin lesions, and lowered inflammatory cytokines (IL-6, IL-17, TNFα) in at least one patient.

2013 · Shimouchi et al. — Molecular hydrogen consumption in the human body during the inhalation of hydrogen gas.

Advances in experimental medicine and biology

Using a gas chromatography method, this study measured the rate at which the human body consumes inhaled H₂ gas and confirmed a consumption rate of approximately 0.7 µmol/min/m² body surface area — closely matching prior data from H₂-rich water ingestion.

2010 · Nakayama et al. — A Novel Bioactive Haemodialysis System Using Dissolved Dihydrogen (H₂) Produced by Water Electrolysis: A Clinical Trial

Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association

Adding dissolved molecular hydrogen to dialysis solution significantly reduced blood pressure and inflammatory markers in hemodialysis patients.

2026 · Wang — Hydrogen gas inhalation alleviated cerebral ischemia/reperfusion injury by regulating mitophagy in SH-SY5Y cells and mice via PTEN-induced kinase 1/Parkin pathway.

Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association

Inhaling molecular hydrogen (H₂) after a stroke-like event (cerebral ischemia/reperfusion) significantly reduced brain tissue damage, neuronal death, and neurological deficits in both mouse models and cell cultures.

2026 · Sato — Optimization of lens size and ion source parameters for gas chromatography/mass spectrometry-based metabolomics using hydrogen as a carrier gas

Journal of chromatography. A

Global helium shortages are pushing analytical chemistry laboratories to adopt hydrogen gas as an alternative carrier gas for GC/MS metabolomics — but hydrogen causes unwanted ion-source reactions that alter fragmentation patterns.

2026 · Zhao — Molecular hydrogen triggers TRPC4-TRPC4AP-dependent reversible calcium transients via extracellular influx

Theranostics

For the first time, researchers have identified a specific ion channel — TRPC4, activated via its binding partner TRPC4AP — as the molecular target through which inhaled hydrogen gas triggers rapid, reversible calcium signals in living cells and in the brains and skin of living mice.

2026 · Kiyoi — Transcriptome-Based Evaluation of Hydrogen Gas Effects for Preventing UVA-Induced Photoaging Using an Artificial Skin Model

Geriatrics & gerontology international

Hydrogen gas inhalation may protect skin against UV-A induced photoaging — not just by scavenging free radicals, but by modulating specific gene expression pathways including NRF2-mediated antioxidant defence and the p53-mediated senescence pathway.

2026 · Li — MXene-Engineered MgB₂ Nanoprodrugs with Acid-Responsive Hydrogen Evolution for Cooperative Photothermal Cancer Ablation

ACS applied materials & interfaces

Researchers engineered a nanoparticle system (MgB₂-Ti₃C₂Tₓ@PEG) that releases hydrogen gas specifically within the acidic tumor microenvironment and simultaneously converts near-infrared laser light into heat — combining hydrogen gas therapy with photothermal tumor ablation.

2026 · Cao — A Hydrogen Generator Enhances Immunogenic Transarterial Chemoembolization in Hepatocellular Carcinoma

Journal of controlled release : official journal of the Controlled Release Society

Adding a hydrogen-releasing material (nano-CaH₂) to the standard TACE (transarterial chemoembolization) procedure for liver cancer enabled local H₂ release that reduced tumor hypoxia, enhanced drug effectiveness, and activated anti-tumor immune responses — all demonstrated in animal models.

2026 · Liang — Synergistic Calcium Overload and Hydrogen Release Potentiate Robust Antitumor Immunity

Advanced healthcare materials

A nanoplatform called Ca@CMPN combines calcium hydride and curcumin to simultaneously flood cancer cells with calcium ions (triggering immunogenic cell death) and release H₂ to reduce oxidative stress and reshape the immunosuppressive tumor microenvironment.

2026 · Zhang — Pearl-Like Bioinspired Coating Enables Regulation of Mg Degradation for Osteoporotic Bone Repair

Advanced science (Weinheim, Baden-Wurttemberg, Germany)

A pearl-inspired multilayer coating for magnesium alloy bone implants was developed to precisely control the rate at which magnesium degrades in osteoporotic bone — specifically preventing premature hydrogen gas release, which can cause local tissue problems.

2025 · Wang — Spontaneous Hydrogen-releasing Nanoenzyme Alleviates Osteoarthritis via Oxidative Stress Reduction and Mitochondrial Dysfunction Reversal

Journal of nanobiotechnology

A newly engineered nanoenzyme that spontaneously releases hydrogen gas alleviated osteoarthritis in animal experiments by reducing oxidative stress, restoring mitochondrial function, promoting the clearance of damaged mitochondria (mitophagy), and slowing cartilage degeneration.

2025 · Maier — Biomechanical Analysis of Biodegradable Magnesium, Zinc, and Polylactide Pins for Fixation of Radial Head Fractures

Journal of orthopaedic surgery and research

Biodegradable magnesium and zinc pins outperformed polylactide pins in laboratory biomechanical testing for radial head fracture fixation, with magnesium pins showing the highest stiffness and lowest fracture displacement.

2025 · Yin — Research on the Inhibitory Effect of Hydrogen Gas on Ovarian Cancer and Potential Mechanisms

European journal of medical research

Hydrogen gas inhibited ovarian cancer cell viability, migration, and invasion, promoted apoptosis, and reduced tumour size in both cell and animal experiments by modulating oxidative stress markers and suppressing key oncogenic proteins (HIF-1α, NF-κB p65).

2025 · Wang — Hierarchical ROS-scavenging platform breaks vicious cycle of stem cell senescence, angiogenesis arrest, and immune dysregulation in diabetic wounds.

Journal of controlled release : official journal of the Controlled Release Society

Diabetic chronic wounds are driven by a self-reinforcing cycle of oxidative stress, stem cell ageing, impaired blood-vessel growth, and immune imbalance.

2025 · Lu — Pyroptosis-responsive microspheres modulate the inflammatory microenvironment to retard osteoporosis in female mice.

Nature communications

Bone loss in osteoporosis is partly driven by a destructive inflammation mechanism called pyroptosis — and a newly designed implantable microsphere scaffold that releases hydrogen gas, magnesium ions, and an anti-inflammatory drug simultaneously can interrupt this process.

2025 · Zhang — Hydrogen attenuates the senescence of adipose-derived stem cells and enhances their myogenic differentiation via modulation of the PRDX6/SIRT1/PGC-1α signaling pathway.

Human & experimental toxicology

Stem cells derived from fat tissue age over time, limiting their potential for regenerative therapies — and hydrogen gas treatment can slow this ageing while simultaneously improving the cells' ability to differentiate into muscle tissue.

2025 · Zhang — RNA-Seq Reveals the Mechanism of Synergistic Hydrogen-Chemotherapy Based on Active Magnesium Micromotors for Inhibiting Glioblastoma Recurrence by Modulating Tumor Microenvironment.

Small (Weinheim an der Bergstrasse, Germany)

Glioblastoma (GBM) almost always returns after surgery — and a new approach using self-propelled magnesium micromotors that generate hydrogen gas locally and simultaneously deliver chemotherapy drug doxorubicin may significantly inhibit this recurrence.

2025 · Lu — Dietary addition of magnesium hydride nanoparticles: a breakthrough in combating high-fat diet-induced chronic kidney disease.

Medical gas research

A high-fat diet gradually damages the kidneys — and feeding mice magnesium hydride (MgH₂) nanoparticles, which release hydrogen gas continuously in the digestive tract, provided significant protection against this kidney damage by reducing fibrosis and inflammation.

2025 · Du — A partially degradable composite consisting of Ti-Zr-Cu-Pd-Sn metallic glass and Fe-Mg alloy for orthopedic applications.

Acta biomaterialia

Researchers combined a titanium-based metallic glass with an iron-magnesium alloy into a novel partially degradable bone implant.

2025 · Lin — Galvanic Cell Bipolar Microneedle Patches for Reversing Photoaging Wrinkles.

Advanced materials (Deerfield Beach, Fla.)

A microneedle patch containing magnesium-based bipolar electrodes generates microcurrents and releases hydrogen gas and magnesium ions directly in the skin via a galvanic cell reaction.

2025 · Mancebo — Performance of Unmodified Mechanical Ventilators With 2% Hydrogen Gas Mixtures.

Respiratory care

Can standard, unmodified intensive-care ventilators safely deliver a 2% H₂ gas mixture?

2025 · Yang — Manganese Galvanic Cells Intervene in Tumor Metabolism to Reinforce cGAS-STING Activation for Bidirectional Synergistic Hydrogen-Immunotherapy.

Advanced materials (Deerfield Beach, Fla.)

Manganese galvanic-cell nanostructures (MnG) generate hydrogen and manganese ions inside tumours by reacting with water, simultaneously activating a key innate-immunity pathway (cGAS-STING) and disrupting tumour glucose metabolism.

2025 · Ji — Hydrolysis of 2D Nanosheets Reverses Rheumatoid Arthritis Through Anti-Inflammation and Osteogenesis.

Advanced materials (Deerfield Beach, Fla.)

Two-dimensional calcium disilicide nanoparticles (CSN) hydrolyse in joint fluid to release hydrogen gas, calcium hydroxide, and silica simultaneously — tackling three distinct processes that drive rheumatoid arthritis: oxidative stress, joint acidity, and bone erosion.

2025 · Hu — Hydrogen-Generating Magnesium Alloy Seed Strand Sensitizes Solid Tumors to Iodine-125 Brachytherapy.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)

An AZ31 magnesium-alloy brachytherapy seed strand (AMASS) implanted directly into tumours releases hydrogen gas alongside radioactive iodine-125 radiation, significantly enhancing tumour cell killing compared to radiation alone.

2025 · Zhang — Living Therapeutics for Synergistic Hydrogen-Photothermal Cancer Treatment by Photosynthetic Bacteria.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)

Living photosynthetic bacteria (Rhodobacter sphaeroides) were used as a self-powered, targeted platform that simultaneously generates hydrogen gas and converts near-infrared light into heat inside tumours.

2025 · Ji — Mitochondrial 'Birth-Death' Coordinator: An Intelligent Hydrogen Nanogenerator to Enhance Intervertebral Disc Regeneration

Biomaterials

Researchers developed a smart nanoparticle (Fe@HP-OD) that releases molecular hydrogen (H₂) precisely inside degenerated intervertebral discs (IVDs) in response to the local microenvironment.

2024 · Tumurbaatar — The effect of hydrogen gas on the oxidative stress response in adipose tissue.

Scientific reports

Human fat tissue soaked in hydrogen-dissolved culture medium showed reduced markers of harmful oxidative stress and a trend toward smaller fat cell size.

2024 · McCurry — Gut bacteria convert glucocorticoids into progestins in the presence of hydrogen gas.

Cell

Two common gut bacteria can chemically transform stress hormones (glucocorticoids) into sex hormones and neurosteroids (progestins) — and this conversion is significantly boosted by hydrogen gas produced by other gut bacteria.

2024 · Chen et al. — Endogenous Melanin and Hydrogen-Based Specific Activated Theranostics Nanoagents: A Novel Multi-Treatment Paradigm for Rheumatoid Arthritis

Advanced science (Weinheim, Baden-Wurttemberg, Germany)

Researchers developed nanoparticles (MAHI NGs) that release molecular hydrogen, melanin nanoparticles, and a clinical fluorescent dye directly into inflamed joints — guided by the specific chemical environment of rheumatoid arthritis (RA).

2024 · Cui et al. — Molecular Hydrogen Attenuates Sepsis-Induced Cardiomyopathy in Mice by Promoting Autophagy

BMC anesthesiology

In a mouse model of sepsis-induced cardiomyopathy (SIC), molecular hydrogen inhalation significantly improved 7-day survival, reduced cardiac tissue inflammation, and lowered troponin I levels — effects that operated through promotion of autophagy and mitophagy.

2024 · Cui — High-concentration hydrogen inhalation mitigates sepsis-associated encephalopathy in mice by improving mitochondrial dynamics

CNS Neuroscience & Therapeutics

Inhaling high-concentration hydrogen (67%) improved the 7-day survival rate and recognition memory in septic mice — through protection of the mitochondria (the power plants of nerve cells) and less inflammation.

2024 · Wang — Natural hydrogen gas and engineered microalgae prevent acute lung injury in sepsis

Materials Today Bio

Inhaled hydrogen gas protects the lung in sepsis — and a novel nanosystem of H₂-releasing particles plus microalgae (DQB@C) amplifies this protection in a mouse model by curbing inflammation, oxidative stress and „ferroptosis“ (iron-dependent cell death).

2023 · Aokage — Attenuation of pulmonary damage in aged lipopolysaccharide-induced inflammation mice through continuous 2 % hydrogen gas inhalation: A potential therapeutic strategy for geriatric inflammation and survival

Experimental gerontology

In aged mice (21–23 months) with LPS-induced systemic inflammation, continuous inhalation of 2 % hydrogen gas for 24 hours reduced lung inflammation, lowered senescence-related markers, and improved survival — while having no measurable effect on LPS-induced liver injury.

2023 · Liu — Hydrogen gas ameliorates acute alcoholic liver injury via anti-inflammatory and antioxidant effects and regulation of intestinal microbiota

International immunopharmacology

In a mouse model of acute alcoholic liver disease, H₂ inhalation reduced liver oxidative stress, inflammation, and fat accumulation, while also improving the composition of the gut microbiota and strengthening the intestinal barrier.

2023 · Kiyoi — Intermittent environmental exposure to hydrogen prevents skin photoaging through reduction of oxidative stress

Geriatrics & gerontology international

In a mouse model, nightly exposure to 1.3 % hydrogen gas for 6 weeks reduced UVA-induced skin aging: fewer senescent cells, less epidermal thickening, reduced melanogenesis, and less collagen degradation in the dermis.

2023 · Son — PdO-Nanoparticle-Embedded Carbon Nanotube Yarns for Wearable Hydrogen Gas Sensing Platforms with Fast and Sensitive Responses

ACS sensors

Researchers developed a flexible yarn-type sensor that detects explosive hydrogen concentrations within two seconds — opening a path toward wearable H₂ safety monitors.

2023 · Iketani — H₂-induced transient upregulation of phospholipids with suppression of energy metabolism

Medical gas research

Short exposure to molecular hydrogen transiently shifts the lipid composition of neuroblastoma cells and temporarily suppresses their energy metabolism — a complex cellular response that hints at how H₂ may interact with cell membranes.

2023 · Kopp — Long-term in vivo observations show biocompatibility and performance of ZX00 magnesium screws surface-modified by plasma-electrolytic oxidation in Göttingen miniature pigs

Acta biomaterialia

Bioabsorbable magnesium bone screws with a special surface coating (plasma-electrolytic oxidation) showed good biocompatibility and significantly slower, more controlled degradation over 18 months in large animals — with H₂ evolution serving as a standard measurement tool during in-vitro degradation testing, not as a therapy.

2023 · Videhult Pierre — Hydrogen Gas Inhalation Attenuates Acute Impulse Noise Trauma: A Preclinical In Vivo Study

The Annals of otology, rhinology, and laryngology

In guinea pigs subjected to extremely loud impulse noise (156 dB), inhaling 2% H₂ immediately afterwards significantly reduced hearing threshold shifts and inner ear hair cell loss compared to noise-only controls.

2022 · Yamamoto et al. — Development of a Model System for Gas Cavity Formation Behavior of Magnesium Alloy Implantation

ACS biomaterials science & engineering

This study developed an in-vitro gelatin model to simulate and measure the hydrogen gas cavities that form in tissue when biodegradable magnesium (Mg) bone screws corrode — a known clinical challenge in orthopaedic surgery.

2022 · Catlett — Metabolic Synergy between Human Symbionts Bacteroides and Methanobrevibacter

Microbiology spectrum

Two dominant gut microbes — Bacteroides thetaiotaomicron and the hydrogen-consuming archaeon Methanobrevibacter smithii — form a mutual metabolic partnership that depends on hydrogen gas.

2022 · Adzavon — Long-term and daily use of molecular hydrogen induces reprogramming of liver metabolism in rats by modulating NADP/NADPH redox pathways

Scientific reports

Rats exposed to molecular hydrogen for six months — either by drinking hydrogen-rich water or inhaling 4 % H₂ gas — showed reduced fat accumulation in the liver, lower blood lipid levels, and broad metabolic changes driven by the NADP/NADPH redox system.

2022 · Ge — Microbial hydrogen economy alleviates colitis by reprogramming colonocyte metabolism and reinforcing intestinal barrier

Gut microbes

In mice with experimentally induced acute colitis, hydrogen-rich saline administration reduced intestinal inflammation, increased beneficial short-chain fatty acid (SCFA)-producing bacteria, and strengthened the gut barrier.

2022 · An — Gender-based differences in neuroprotective effects of hydrogen gas against intracerebral hemorrhage-induced depression

Neurochemistry international

In a mouse model of intracerebral hemorrhage (ICH), hydrogen gas inhalation provided stronger neuroprotective effects against post-stroke depression in female mice than in males — and adding estrogen to male mice restored comparable H₂ efficacy.

2022 · Liu — In vivo microelectrode monitoring of real-time hydrogen concentration in different tissues of rats after inhaling hydrogen gas

Medical gas research

Using implanted electrochemical microelectrodes, researchers measured hydrogen concentrations in seven different rat tissues in real time during and after inhalation of 4 %, 42 %, and 67 % H₂ gas.

2021 · Yin et al. — Hydrogen Gas with Extracorporeal Cardiopulmonary Resuscitation Improves Survival after Prolonged Cardiac Arrest in Rats

Journal of translational medicine

In a rat model of prolonged cardiac arrest, adding hydrogen gas (H₂) to extracorporeal cardiopulmonary resuscitation (ECPR) dramatically improved 4-hour survival: 78% with H₂ versus 22% without.

2021 · Yuan et al. — In Situ Hydrogen Nanogenerator for Bimodal Imaging Guided Synergistic Photothermal/Hydrogen Therapies

Nanoscale

This nanotechnology study developed a nanoparticle system that generates hydrogen gas locally within tumors, combining hydrogen therapy with photothermal therapy (heat-based cancer treatment) to kill cancer cells.

2021 · van Gelder et al. — Safety of Electrooxidation for Urea Removal in a Wearable Artificial Kidney Is Compromised by Formation of Glucose Degradation Products

Artificial organs

A wearable artificial kidney (WAK) using electrooxidation to destroy urea in dialysate generates dangerous glucose degradation products — making the current approach unsafe for clinical use.

2021 · Spanoghe et al. — Microbial Food from Light, Carbon Dioxide and Hydrogen Gas: Kinetic, Stoichiometric and Nutritional Potential of Three Purple Bacteria

Bioresource technology

Purple bacteria can grow using light, CO₂, and hydrogen gas as their sole energy and carbon sources, producing protein-rich biomass with complete dietary amino acid profiles.

2021 · Chu — Mechanism of hydrogen on cervical cancer suppression revealed by high-throughput RNA sequencing

Oncology reports

H₂ inhalation suppressed the growth of cervical cancer cells in the laboratory and in a mouse xenograft model, apparently by switching off two key cancer-promoting proteins — HIF-1α and NF-κB p65.

2021 · Zhang — Molecular hydrogen alleviates asthma through inhibiting IL-33/ILC2 axis

Inflammation research : official journal of the European Histamine Research Society ... [et al.]

In an OVA-sensitised mouse model of asthma and a bronchial epithelial cell model, hydrogen/oxygen gas mixture inhalation markedly reduced allergic inflammation by suppressing the IL-33/ILC2 signalling axis.

2021 · Li — Hydrogen Attenuates Endotoxin-Induced Lung Injury by Activating Thioredoxin 1 and Decreasing Tissue Factor Expression

Frontiers in immunology

In a mouse model of endotoxin-induced lung injury, H₂ inhalation significantly improved survival, reduced pulmonary oedema, and decreased neutrophil infiltration — apparently by activating the antioxidant protein Thioredoxin 1 (Trx1), which in turn suppressed tissue factor (TF) and MMP-9.

2021 · Matsuura — Hydrogen Gas Therapy Attenuates Inflammatory Pathway Signaling in Septic Mice

The Journal of surgical research

In a mouse cecal ligation and puncture (CLP) sepsis model, continuous H₂ inhalation improved 7-day survival from 40% to 75% and suppressed systemic and organ-level inflammatory signalling.

2021 · Hartjen — Toward Tailoring the Degradation Rate of Magnesium-Based Biomaterials for Various Medical Applications: Assessing Corrosion, Cytocompatibility and Immunological Effects

International journal of molecular sciences

This in-vitro materials science study tested a surface-treated magnesium alloy (WE43 with plasma electrolytic oxidation) as a degradable implant material.

2021 · Duffner — Dechloromonas and close relatives prevail during hydrogenotrophic denitrification in stimulated microcosms with oxic aquifer material

FEMS microbiology ecology

When hydrogen gas was added to groundwater microcosms contaminated with nitrate, a specific genus of bacteria (Dechloromonas) dominated the resulting nitrate-removal community.

2021 · Gopi — Cobalt-modified 2D porous organic polymer for highly efficient electrocatalytic removal of toxic urea and nitrophenol

Chemosphere

This electrochemistry study developed a cobalt-doped porous organic polymer that can efficiently catalyse the oxidation of urea and reduction of 4-nitrophenol from wastewater.

2021 · Ostojic — Does drinking water rich in hydrogen gas revive brain hypometabolism in neurodegeneration by SCFAs upregulation?

European journal of clinical nutrition

This theoretical commentary proposes a speculative mechanism: that hydrogen-rich water (HRW) might help restore brain energy metabolism in neurodegenerative disease by increasing short-chain fatty acids (SCFAs) in the gut.

2020 · Ostojic — COVID-19 and Molecular Hydrogen Inhalation

Therapeutic advances in respiratory disease

This is a brief theoretical commentary exploring whether molecular hydrogen inhalation could play a supportive role in COVID-19 management, based on H₂'s known anti-inflammatory and antioxidant properties.

2020 · De Paepe — Bio-electrochemical COD Removal for Energy-efficient, Maximum and Robust Nitrogen Recovery from Urine through Membrane Aerated Nitrification

Water research

This study develops a two-stage electrochemical urine treatment system for sustainable nitrogen recovery — primarily for space exploration applications.

2020 · Sun — Photoactivated H₂ Nanogenerator for Enhanced Chemotherapy of Bladder Cancer

ACS nano

Researchers designed nanoparticles that generate H₂ gas inside cancer cells when activated by a 660 nm laser, finding in cell culture and mouse models that H₂ produced in this way significantly enhanced the efficacy of the chemotherapy drug gemcitabine against bladder cancer.

2020 · Meng — Hydrogen Gas Represses the Progression of Lung Cancer via Down-regulating CD47

Bioscience reports

In lung cancer cell lines and a mouse tumour model, hydrogen gas treatment reduced the expression of CD47 — a „don't eat me“ signal that cancer cells use to evade immune destruction — and thereby inhibited cancer cell growth, invasion, migration, and promoted macrophage-mediated tumour cell clearance.

2020 · Kiyoi — Constitutive Hydrogen Inhalation Prevents Vascular Remodeling via Reduction of Oxidative Stress

PloS one

In a mouse model of cuff-induced vascular injury, continuous inhalation of 1.3 % hydrogen gas for several weeks significantly reduced abnormal vascular wall thickening (neointima formation) — an effect associated with decreased DNA damage and downregulation of the NADPH oxidase NOX1.

2020 · Zhuang — Molecular hydrogen attenuates sepsis-induced neuroinflammation through regulation of microglia polarization through an mTOR-autophagy-dependent pathway.

International immunopharmacology

In both a mouse sepsis model (cecal ligation and puncture) and LPS-stimulated BV-2 microglial cells, inhaled hydrogen reduced neuroinflammation, shifted microglia from a pro-inflammatory (M1) to an anti-inflammatory (M2) state, and improved cognitive function.

2020 · Ruaud — Syntrophy via Interspecies H₂ Transfer between Christensenella and Methanobrevibacter Underlies Their Global Cooccurrence in the Human Gut.

mBio

This microbiome study shows that gut bacteria of the genus Christensenella produce hydrogen gas (H₂) that is consumed by the archaeon Methanobrevibacter smithii — a metabolic partnership that explains why these two microbes co-occur globally and correlate with a lean body-mass index.

2020 · Oh — Untethered Soft Robotics with Fully Integrated Wireless Sensing and Actuating Systems for Somatosensory and Respiratory Functions.

Soft robotics

This engineering study presents a wireless soft robotic hand that integrates flexible sensors — including a hydrogen gas sensor — for monitoring tactile pressure, temperature, and H₂ concentration via smartphone.

2019 · Chen et al. — Inhaling Hydrogen Ameliorates Early Postresuscitation EEG Characteristics in an Asphyxial Cardiac Arrest Rat Model.

BioMed research international

In a rat model of asphyxial cardiac arrest, breathing 2% hydrogen gas after resuscitation dramatically improved both survival (90% vs. 40%) and the recovery of brain electrical activity (EEG) within four hours.

2019 · Jung — In Vivo Simulation of Magnesium Degradability Using a New Fluid Dynamic Bench Testing Approach

International journal of molecular sciences

A new dynamic test bench was constructed to measure hydrogen gas (H₂) release during the degradation of magnesium-based implants — using H₂ evolution as a proxy for degradation rate under physiological conditions.

2019 · Kobayashi — Organ Preservation Solution Containing Dissolved Hydrogen Gas from a Hydrogen-Absorbing Alloy Canister Improves Function of Transplanted Ischemic Kidneys in Miniature Pigs

PloS one

Adding dissolved molecular hydrogen (H₂) to the organ preservation solution — via a rapid, practical canister method — significantly improved kidney function after transplantation from donors with circulatory arrest in miniature pigs.

2019 · Zhang — Hydrogen Gas Improves Photothermal Therapy of Tumor and Restrains the Relapse of Distant Dormant Tumor

Biomaterials

A biomimetic nanoparticle (mPDAB) that releases molecular hydrogen (H₂) locally in the tumor was combined with photothermal therapy (PTT) in a mouse breast cancer model, leading to complete elimination of primary tumors and suppression of distant dormant tumor regrowth.

2019 · Liu — Molecular Hydrogen Suppresses Glioblastoma Growth via Inducing the Glioma Stem-Like Cell Differentiation

Stem cell research & therapy

In rat and mouse glioblastoma (GBM) models, daily inhalation of 67% hydrogen gas suppressed tumor growth, prolonged survival, and induced differentiation of cancer stem-like cells — reducing their self-renewal, proliferation, and invasive capacity.

2019 · Wu — Hydrogen gas protects against ovariectomy-induced osteoporosis by inhibiting NF-κB activation.

Menopause (New York, N.Y.)

In mice with surgically induced estrogen deficiency (ovariectomy model of postmenopausal osteoporosis), inhalation of 60 % molecular hydrogen (H₂) markedly reduced bone loss.

2019 · Yan — Hydrogen gas inhalation attenuates sepsis-induced liver injury in a FUNDC1-dependent manner.

International immunopharmacology

In septic mice (cecal ligation and puncture model), 2 % hydrogen (H₂) gas inhalation for 3 hours improved the 7-day survival rate and reduced markers of liver damage.

2019 · Liu — In vitro and in vivo studies of Mg-30Sc alloys with different phase structure for potential usage within bone.

Acta biomaterialia

Researchers developed a magnesium-scandium (Mg-30Sc) alloy with a body-centred-cubic (bcc) crystal structure as a biodegradable orthopaedic implant material and tested it in cell cultures and rats over 24 weeks.

2019 · Zhu — Mechanical Strength, Biodegradation, and in Vitro and in Vivo Biocompatibility of Zn Biomaterials.

ACS applied materials & interfaces

Zinc (Zn)-based alloys were evaluated as a new class of biodegradable metal implant materials — notable specifically because they degrade without producing hydrogen gas, unlike magnesium-based implants.

2019 · Yu — Hydrogen gas reduces HMGB1 release in lung tissues of septic mice in an Nrf2/HO-1-dependent pathway.

International immunopharmacology

In septic mice (CLP model), 2 % hydrogen (H₂) gas inhalation reduced lung injury, improved survival, and decreased the release of HMGB1 — a late-phase danger signal in sepsis — through a pathway requiring the Nrf2 transcription factor and the enzyme HO-1.

2019 · Guan — Hydrogen gas reduces chronic intermittent hypoxia-induced hypertension by inhibiting sympathetic nerve activity and increasing vasodilator responses via antioxidation.

Journal of cellular biochemistry

In rats subjected to chronic intermittent hypoxia (CIH) — a model of sleep-apnoea-related hypertension — daily H₂ gas inhalation significantly attenuated the rise in blood pressure.

2018 · Dong — Protective effects of hydrogen gas against sepsis-induced acute lung injury via regulation of mitochondrial function and dynamics

International immunopharmacology

In a mouse model of sepsis-induced acute lung injury (ALI), inhaling 2% hydrogen gas improved lung oxygenation, preserved mitochondrial membrane potential and ATP production, and reduced tissue damage compared to untreated septic animals.

2018 · Perisin — Human gut microbe co-cultures have greater potential than monocultures for food waste remediation to commodity chemicals

Scientific reports

This computational study models how co-cultures of human gut bacteria convert food waste to useful chemicals (butanol, acetate, hydrogen gas, methane) more efficiently than monocultures.

2018 · Wan — An In Situ Depot for Continuous Evolution of Gaseous H₂ Mediated by a Magnesium Passivation/Activation Cycle for Treating Osteoarthritis

Angewandte Chemie (International ed. in English)

This mouse study tested intra-muscular injection of magnesium-containing microparticles (Mg@PLGA) as a local H₂ delivery system for osteoarthritis (OA).

2018 · Wang — Hydrogen gas inhibits lung cancer progression through targeting SMC3

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie

In lung cancer cell lines and a mouse xenograft model, hydrogen gas (H₂) inhibited cell viability, migration, and invasion while promoting apoptosis — apparently by downregulating SMC3, a chromosome condensation regulator.

2017 · Watanabe — Protective Effect of Hydrogen Gas Inhalation on Muscular Damage Using a Mouse Hindlimb Ischaemia-Reperfusion Injury Model

Plastic and reconstructive surgery

In a mouse hindlimb ischaemia-reperfusion model, inhalation of hydrogen gas — administered before and during reperfusion — significantly reduced muscle infarct zone, dampened inflammation, and improved walking function recovery.

2017 · Asanuma — Translational Study of Hydrogen Gas Inhalation as Adjuncts to Reperfusion Therapy for Acute Myocardial Infarction

Circulation journal : official journal of the Japanese Circulation Society

This translational study investigated hydrogen gas inhalation as an add-on to reperfusion therapy in acute myocardial infarction — bridging animal and early clinical research.

2017 · Murakami — Molecular hydrogen protects against oxidative stress-induced SH-SY5Y neuroblastoma cell death through the process of mitohormesis

PloS one

In cultured human neuroblastoma cells, both H₂ gas and hydrogen-rich water boosted mitochondrial membrane potential and ATP levels while triggering a mild oxidative signal that activated Nrf2-pathway antioxidant enzymes — a hormetic response the authors call „mitohormesis“.

2016 · Wang — Hydrogen Metabolism in Helicobacter pylori Plays a Role in Gastric Carcinogenesis through Facilitating CagA Translocation

mBio

This animal and cell study shows that the bacterium Helicobacter pylori uses molecular hydrogen — produced by the gut microbiome — as an energy source to power delivery of its cancer-causing toxin CagA into stomach cells, promoting gastric cancer development in a gerbil model.

2016 · Hara — Molecular Hydrogen Alleviates Cellular Senescence in Endothelial Cells

Circulation journal : official journal of the Japanese Circulation Society

In human vascular endothelial cells exposed to a toxic compound (TCDD), hydrogen-rich medium prevented signs of cellular ageing (senescence) even after H₂ had dissipated from the medium — an effect mediated by the antioxidant transcription factor Nrf2.

2016 · Muramatsu — Hydrogen-Rich Water Ameliorates Bronchopulmonary Dysplasia (BPD) in Newborn Rats

Pediatric pulmonology

Hydrogen-rich water given to pregnant and nursing rats reduced lung damage caused by a bacterial toxin in newborn animals.

2016 · Iuchi — Molecular Hydrogen Regulates Gene Expression by Modifying the Free Radical Chain Reaction-Dependent Generation of Oxidized Phospholipid Mediators

Scientific reports

Molecular hydrogen (H₂) may regulate gene expression not by directly targeting DNA or transcription factors, but by modifying how oxidized phospholipids are produced through free radical chain reactions.

2016 · Yang — Hydrogen-Rich Medium Ameliorates Lipopolysaccharide-Induced Barrier Dysfunction via RhoA-mDia1 Signaling in Caco-2 Cells

Shock (Augusta, Ga.)

In intestinal epithelial cells (Caco-2), hydrogen-rich medium protected the gut barrier from LPS-induced permeability increase by modulating the RhoA-mDia1 signaling pathway, which governs tight junction and adherens junction integrity.

2015 · Shi et al. — Hydrogen Therapy Reduces Oxidative Stress-associated Risks Following Acute and Chronic Exposure to High-altitude Environment.

Biomedical and environmental sciences : BES

This theoretical paper proposes that inhaling low-dose H₂ gas or drinking hydrogen-saturated water could prevent and treat mountain sickness by counteracting the oxidative stress caused by high-altitude low-oxygen and high-UV conditions.

2015 · Keles et al. — Can an innocent toy become dangerous? The hydrogen gas balloon burn.

Burns : journal of the International Society for Burn Injuries

Hydrogen gas, used to fill balloons, can ignite and cause severe burns — a safety risk that is rarely discussed.

2015 · Barbu et al. — The use of hydrogen gas clearance for blood flow measurements in single endogenous and transplanted pancreatic islets.

Microvascular research

Researchers used hydrogen gas as a tracer — not as therapy — to precisely measure blood flow in individual pancreatic islets in rats and mice.

2014 · Bazaka et al. — Polymer encapsulation of magnesium to control biodegradability and biocompatibility.

Journal of nanoscience and nanotechnology

This animal and cell study investigated plasma-polymerised coatings on biodegradable magnesium implants — where hydrogen gas appears as an unwanted by-product of magnesium corrosion, not as a therapeutic agent.

2014 · Nazreen et al. — Thiazolidine-2,4-diones derivatives as PPAR-γ agonists: synthesis, molecular docking, in vitro and in vivo antidiabetic activity with hepatotoxicity risk evaluation.

Bioorganic & medicinal chemistry letters

This in-vitro and animal pharmacology study synthesised new thiazolidinedione-chromone compounds as potential antidiabetic agents — using hydrogen gas as a chemical reducing agent in the synthesis process, not as a therapeutic substance.

2014 · Chen — Controlling initial biodegradation of magnesium by a biocompatible strontium phosphate conversion coating

Acta biomaterialia

Magnesium implants dissolve too quickly after implantation — a strontium phosphate (SrP) coating developed in this in-vitro study significantly slows this degradation.

2013 · Johnsen — A non-aqueous reduction process for purifying ¹⁵³Gd produced in natural europium targets

Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine

This nuclear medicine radiochemistry study developed a methanol-based purification process for Gadolinium-153 (a medical imaging quality-assurance isotope) that nearly eliminates the hazardous hydrogen gas produced by conventional aqueous europium reduction.

2013 · Wang et al. — A surface-eroding poly(1,3-trimethylene carbonate) coating for fully biodegradable magnesium-based stent applications.

Acta biomaterialia

This materials science study investigated a biodegradable polymer coating (PTMC) for magnesium-based cardiovascular stents — aiming to control corrosion and improve biocompatibility.

2012 · Wong et al. — A hydrogen gas-water equilibration method produces accurate and precise stable hydrogen isotope ratio measurements in nutrition studies.

The Journal of nutrition

This analytical chemistry study validated a platinum-catalysed hydrogen gas–water equilibration method for measuring stable hydrogen isotope ratios (deuterium) in body fluids — used in nutrition research to measure body composition and energy expenditure.

2012 · Takeuchi et al. — Hydrogen may inhibit collagen-induced platelet aggregation: an ex vivo and in vivo study.

Internal medicine (Tokyo, Japan)

In this mixed-design study — combining human ex vivo blood tests and rat in vivo experiments — molecular hydrogen (via H₂ saline or H₂ inhalation) significantly inhibited collagen-induced platelet aggregation.

2012 · Qian et al. — Hydrogen therapy may be an effective and specific novel treatment for aplastic anemia.

Medical science monitor : international medical journal of experimental and clinical research

Aplastic anemia is a severe bone marrow failure disease with high mortality — and oxidative stress and inflammatory cytokines like TNF-α and IL-6 play a central role in its development.

2012 · Baxter et al. — Evaluation of outgassing, tear strength, and detail reproduction in alginate substitute materials.

Operative dentistry

This study compares dental impression materials (alginate substitutes) to traditional alginate for three performance properties: the release of hydrogen gas (outgassing), tear strength, and detail reproduction quality.

2011 · Terasaki — Hydrogen Therapy Attenuates Irradiation-Induced Lung Damage by Reducing Oxidative Stress

American journal of physiology. Lung cellular and molecular physiology

In irradiated human lung cells and in mice given whole-thorax irradiation, molecular hydrogen (H₂) — delivered as H₂-rich PBS, H₂-enriched drinking water, or 3% H₂ inhalation — significantly reduced oxidative stress markers, apoptosis, and lung fibrosis.

2011 · Gao — Fabrication and Characterization of Bioactive Composite Coatings on Mg-Zn-Ca Alloy by MAO/Sol-Gel

Journal of materials science. Materials in medicine

This in-vitro materials science study develops a two-layer protective coating for magnesium alloy implants that dramatically reduces corrosion and supports cell adhesion — addressing one of the main obstacles to using biodegradable magnesium in medical implants, namely the rapid release of hydrogen gas during degradation.

2011 · Chuai — A Possible Prevention Strategy of Radiation Pneumonitis: Combine Radiotherapy with Aerosol Inhalation of Hydrogen-Rich Solution

Medical science monitor : international medical journal of experimental and clinical research

This theoretical paper proposes that combining radiotherapy with aerosol inhalation of hydrogen-rich physiological saline could reduce radiation pneumonitis — a serious complication of lung cancer radiotherapy — by exploiting H₂'s ability to scavenge the hydroxyl radicals that cause most radiation-induced cell damage.

2011 · Chai — Perfusion Electrodeposition of Calcium Phosphate on Additive Manufactured Titanium Scaffolds for Bone Engineering

Acta biomaterialia

This biomaterials engineering study develops a perfusion-based electrodeposition system to uniformly coat 3D-printed titanium bone scaffolds with hydroxyapatite — a calcium phosphate mineral that promotes bone cell adhesion and growth — while addressing hydrogen gas removal as a technical process challenge.

2011 · Schoenfeld — Hydrogen Therapy May Reduce the Risks Related to Radiation-Induced Oxidative Stress in Space Flight

Medical hypotheses

This hypothesis paper proposes that astronauts exposed to cosmic radiation during space missions could benefit from H₂ therapy — via inhalation or hydrogen-rich drinking water — to counteract the oxidative and DNA damage caused by cosmic radiation.

2010 · Liu — Oral administration of mannitol may be an effective treatment for ischemia-reperfusion injury.

Medical hypotheses

This hypothesis paper proposes that oral mannitol — a sugar alcohol that promotes bacterial hydrogen gas production in the colon — could protect organs from ischaemia-reperfusion injury by raising endogenous H₂ levels.

2010 · Kawasaki — Hydrogen gas treatment prolongs replicative lifespan of bone marrow multipotential stromal cells in vitro while preserving differentiation and paracrine potentials.

Biochemical and biophysical research communications

This in-vitro study found that exposing mesenchymal stem cells (MSCs) to 3 % hydrogen gas during laboratory expansion significantly prolonged their replicative lifespan and preserved their ability to differentiate and secrete therapeutic factors.

2010 · Bolca — Microbial equol production attenuates colonic methanogenesis and sulphidogenesis in vitro.

Anaerobe

This in-vitro gut microbiology study showed that equol-producing bacteria — which consume H₂ gas as part of converting the soy isoflavone daidzein into equol — competitively reduce methane and hydrogen sulphide production in the colon.

2010 · Wong — A biodegradable polymer-based coating to control the performance of magnesium alloy orthopaedic implants.

Biomaterials

This in-vitro and in-vivo study developed a biodegradable polymer coating for magnesium alloy bone implants to control their corrosion rate and reduce the accumulation of hydrogen gas during degradation.

2010 · Sugiyama — Use of laser speckle flowgraphy in ocular blood flow research.

Acta ophthalmologica

This technical review describes laser speckle flowgraphy (LSFG), a non-contact imaging technique for measuring blood flow in the optic nerve head, choroid, retina and iris.

2010 · Liu — Hydrogen therapy may be an effective and specific novel treatment for acute radiation syndrome.

Medical hypotheses

This hypothesis paper proposes that inhaled molecular hydrogen (H₂) could be an effective treatment for acute radiation syndrome (ARS) — the life-threatening condition caused by high-dose whole-body irradiation.

2009 · Suzuki — Are the effects of alpha-glucosidase inhibitors on cardiovascular events related to elevated levels of hydrogen gas in the gastrointestinal tract?

FEBS letters

This theoretical paper proposes that the cardiovascular benefits of alpha-glucosidase inhibitors (such as acarbose) may partly be explained by increased H₂ production in the gut.

2009 · Kajiya — Hydrogen mediates suppression of colon inflammation induced by dextran sodium sulfate.

Biochemical and biophysical research communications

In a mouse model of inflammatory bowel disease, adding molecular hydrogen (H₂) to drinking water significantly suppressed colon inflammation induced by dextran sodium sulfate (DSS).

2009 · Gray-Munro — The mechanism of deposition of calcium phosphate coatings from solution onto magnesium alloy AZ31.

Journal of biomedical materials research. Part A

This in-vitro materials science study investigated how calcium phosphate coatings can be deposited onto magnesium alloy surfaces to slow their degradation in biological environments.

2008 · Song — A role for IOP1 in mammalian cytosolic iron-sulfur protein biogenesis.

The Journal of biological chemistry

This in-vitro cell study identified IOP1 — a mammalian protein homologous to bacterial iron-only hydrogenases — as essential for the maturation of cytosolic iron-sulfur (Fe-S) proteins in human cells.

2008 · Hill — Preliminary tribological evaluation of nanostructured diamond coatings against ultra-high molecular weight polyethylene.

Journal of biomedical materials research. Part B, Applied biomaterials

This in-vitro materials science study evaluated nanostructured diamond (NSD) coatings on titanium alloy as a potential counterface for polyethylene in joint replacement implants.

2008 · Kniess et al. — Practical experiences with the synthesis of [¹¹C]CH₃I through gas phase iodination using a TRACERlabFXC synthesis module

Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine

This in-vitro chemistry study optimises the synthesis of the radiotracer [¹¹C]CH₃I — a carbon-11-labelled compound used in PET imaging — by testing several nickel catalysts for the intermediate hydrogen-reduction step.

2007 · Ohsawa — Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals

Nature Medicine

Hydrogen (H₂) acts as a selective antioxidant: it specifically neutralizes the most aggressive free radical — the hydroxyl radical (•OH) — while leaving the beneficial, signaling oxygen species untouched.

2005 · Decroos et al. — Isolation and characterisation of an equol-producing mixed microbial culture from a human faecal sample and its activity under gastrointestinal conditions

Archives of microbiology

This in-vitro gut microbiome study shows that hydrogen gas produced during gut fermentation stimulates equol production by a mixed bacterial culture derived from human stool.

2002 · Happe — Hydrogenases in green algae: do they save the algae's life and solve our energy problems?

Trends in plant science

Green algae are the only known eukaryotes capable of both photosynthesis and hydrogen metabolism — a dual ability that may hold the key to sustainable H₂ production.

2002 · Peterson — Tritium doses from chronic atmospheric releases: a new approach proposed for regulatory compliance.

Health physics

This theoretical modelling study proposes an improved regulatory model (NEWTRIT) for calculating human doses from atmospheric tritium releases — including tritiated hydrogen gas (HT) and organically bound tritium in food.

1999 · Tomita — Oxygen and hydrogen gas transport through living C6 cell suspensions is faster than that in dead cells.

Advances in experimental medicine and biology

This in-vitro study demonstrates that living C6 (rat glioma) cell suspensions transport both oxygen and molecular hydrogen gas more rapidly than dead cell suspensions.

1999 · Ishikawa — A preventive effect of a selective endothelin-A receptor antagonist, S-0139, on the erythropoietin-induced reduction of the renal cortical blood flow.

Urological research

This animal study in Wistar rats shows that erythropoietin (EPO) reduces renal cortical blood flow (RCBF) by triggering endothelin-1 release, and that the selective ET-A receptor antagonist S-0139 can prevent this reduction.

1999 · Tamori — Role of calcitonin gene-related peptide and capsaicin-sensitive afferents in central thyrotropin-releasing hormone-induced hepatic hyperemia.

European journal of pharmacology

This animal study in anesthetized rats demonstrates that central (intracisternal) injection of a TRH analogue increases hepatic blood flow via capsaicin-sensitive afferent neurons and CGRP — and that blocking either pathway completely abolishes this effect.

1996 · Franić — Radiotoxicity of Tritiated Water and Tritiated Hydrogen

Arhiv za higijenu rada i toksikologiju

Tritiated water (HTO) is far more radiotoxic than tritiated hydrogen gas (HT): inhaling tritiated H₂ gas leads to partial oxidation into HTO in the lungs, meaning the effective dose is higher than previously assumed — and the official toxicity ratio of 1:25,000 (HT vs.

1994 · Florin — A Possible Role for Bile Acid in the Control of Methanogenesis and the Accumulation of Hydrogen Gas in the Human Colon

Journal of gastroenterology and hepatology

This in-vitro study of anaerobic fecal cultures found that primary bile acids inhibit methanogenesis in a dose-dependent manner — suggesting that bile acids regulate the balance between H₂ accumulation and methane production in the human colon.

1993 · Scrimgeour — A Simplified Method for Deuterium/Hydrogen Isotope Ratio Measurements on Water Samples of Biological Origin

Biological mass spectrometry

This methodological study describes an improved technique for measuring the deuterium-to-hydrogen (D/H or ²H/¹H) isotope ratio in biological water samples using platinum catalyst–driven equilibration in Vacutainers — enabling non-invasive assessment of total body water and water turnover in human studies.

1992 · Ellies — Crystallographic Changes in Calcium Phosphates During Plasma-Spraying

Biomaterials

This in-vitro materials science study examined how plasma-spraying calcium phosphate powders — using hydrogen gas as part of the plasma torch process — causes crystallographic transformations, converting some hydroxyapatite (HA) to more-resorbable beta-tricalcium phosphate (β-TCP) and calcium oxide.

1992 · Wong — A New Zinc Product for the Reduction of Water in Physiological Fluids to Hydrogen Gas for ²H/¹H Isotope Ratio Measurements

European journal of clinical nutrition

This methodological study describes a new zinc-based reagent for converting water in physiological fluids to hydrogen gas for deuterium/hydrogen (²H/¹H) isotope ratio analysis — enabling accurate, convenient measurement of total body water and metabolic turnover rates in nutritional research.

1991 · Kawano — Protective Effect of Rebamipide (OPC-12759) on the Gastric Mucosa in Rats and Humans

Nihon yakurigaku zasshi. Folia pharmacologica Japonica

This combined animal and small human study showed that rebamipide — a gastric mucosal protective drug — prevents HCl-ethanol-induced gastric lesions in rats dose-dependently and significantly inhibits mucosal damage in healthy human volunteers, partly by improving mucosal microcirculation as measured by hydrogen gas clearance.

1990 · Gibson — Alternative pathways for hydrogen disposal during fermentation in the human colon.

Gut

When gut bacteria ferment carbohydrates, they produce hydrogen gas that must be disposed of — and the colon has several competing routes for doing so.

1990 · Mitarai — Correlation between gastric microcirculation and mucosal injury after surgical therapy of esophageal varices.

Nihon Geka Gakkai zasshi

Surgery for esophageal varices can substantially reduce blood flow to the stomach lining, and the degree of this reduction correlates directly with post-operative mucosal damage.

1989 · Heizmann — GasPak Plus versus Anaerocult A — two carbon dioxide/hydrogen systems for cultivation of anaerobes.

Zentralblatt fur Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology

Two commercially available CO₂/H₂ gas-generating systems for culturing anaerobic bacteria were compared and found to be equally effective overall, though growth varied considerably between individual bacterial species.

1987 · Wong — Deuterium and oxygen-18 measurements on microliter samples of urine, plasma, saliva, and human milk.

The American journal of clinical nutrition

Improved laboratory methods for measuring stable isotope ratios (deuterium/²H and ¹⁸O) in tiny biological fluid samples — down to 10 microliters — were developed and validated, enabling more precise studies of body composition and energy expenditure in humans.

1986 · Sato — Hemodynamics of the gastric mucosa and gastric ulceration in rats and in patients with gastric ulcer.

Digestive diseases and sciences

A spectrophotometric method for non-invasive assessment of gastric mucosal oxygen supply was validated against hydrogen gas clearance and other blood flow techniques, and applied to study how microcirculation affects ulcer formation in rat stress models and ulcer healing in human patients.

1983 · Homer — Transient solutions of equations for countercurrent capillary exchange.

The American journal of physiology

A mathematical model of countercurrent capillary exchange was developed and applied to the analysis of hydrogen gas exchange in the renal medulla, yielding new estimates of medullary blood flow and revealing how tracer exchange between adjacent capillaries can mimic or distort countercurrent effects.

1983 · Peel — The fatty acyl chain composition of human normal and leukaemic lymphocytes and its modulation by specialised hydrogenation.

Leukemia research

The fatty acid profiles of lymphocytes from chronic lymphocytic leukaemia (CLL) patients show a characteristic pattern — higher oleic acid, lower arachidonic acid — consistent with other cancer cell types.

1982 · Murakami — Contact electrode method in hydrogen gas clearance technique: a new method for determination of regional gastric mucosal blood flow in animals and humans.

Gastroenterology

A new contact electrode method for hydrogen gas clearance was developed to measure regional gastric mucosal blood flow non-destructively, tested in both animal models and human subjects.

1976 · Harding — Characterization of Bacteroides melaninogenicus.

Journal of clinical microbiology

Fifty-eight human isolates of Bacteroides melaninogenicus were systematically classified into three subspecies using seven biochemical characteristics.