Hydrogen Gas Inhalation Improved Intestinal Microbiota in Ulcerative Colitis: A Randomised Double-Blind Placebo-Controlled Trial.
Takafumi Maruyama, Dai Ishikawa, Rina Kurokawa, Hiroaki Masuoka, Kei Nomura, Mayuko Haraikawa, Masayuki Orikasa, Rina Odakura, Masao Koma, Masashi Omori, Hirotaka Ishino, Kentaro Ito, Tomoyoshi Shibuya, Wataru Suda, Akihito Nagahara · Biomedicines · 2025
Research-use notice
Independent study record
Each H2HUBB study page organizes source-linked research details for educational use. Interpretation should remain proportional to the study design, population, controls, and limitations.
H2HUBB TAKEAWAY
These findings add human evidence that helps define the outcomes that did and did not change with molecular hydrogen in this study.
What the Findings Mean
The hydrogen group showed higher α-diversity (p = 0.19), and the variation in β-diversity was markedly different, compared to the placebo group, in intestinal microbiota analysis (p = 0.02).
What the Researchers Studied
The study used a randomized, double-blind, placebo-controlled human clinical trial. The comparison condition was placebo.
What Effects Did Molecular Hydrogen Have?
Source-reported hydrogen concentration: 6% source-reported H₂ gas concentration; Source-reported hydrogen exposure: 6% source-reported H₂ gas concentration; 4 L/min H₂ flow (4000 mL/min H₂); reported treatment duration: 8 weeks. The hydrogen group showed higher α-diversity (p = 0.19), and the variation in β-diversity was markedly different, compared to the placebo group, in intestinal microbiota analysis (p = 0.02). The authors concluded that hydrogen inhalation appeared to improve intestinal microbiota diversity; however, no clear therapeutic effect on ulcerative colitis was observed.
Why These Findings Matter
This publication adds useful evidence about where molecular hydrogen did and did not change the measured outcomes, helping define the larger therapeutic evidence base.
How Strong Is This Evidence?
This is human clinical evidence from a randomized, double-blind, placebo-controlled human clinical trial. H2HUBB interprets the findings in the context of the study design, sample, comparator, and measured outcomes rather than using one publication as a verdict on hydrogen therapy.
Technical Study Details
H2HUBB classifies this publication as human clinical study with human clinical evidence. The reported sample size was 20. The study used a randomized, double-blind, placebo-controlled human clinical trial. The hydrogen delivery method was inhaled hydrogen gas. The source-reported hydrogen concentration was 6% source-reported H₂ gas concentration. The reported treatment duration was 8 weeks.
Limitations and Safety
Reported limitations: However, the wide confidence interval reflects the small sample size and associated uncertainty ( Figure S1a ). the study revealed some trends in microbial composition, such as an improvement in beta diversity, but these findings should be interpreted with caution due to the lack of statistical significance in alpha diversity and the small sample size. Finally, the observed MES reduction should be interpreted cautiously due to the small sample size and potential Type I error. Safety information: In this study, the researchers investigated changes in the intestinal microbiota, therapeutic effects, and safety of hydrogen inhalation in patients with ulcerative colitis. No adverse events were observed during or after H₂ inhalation.
Original Study and H2HUBB Research Context
H2HUBB presents this source-grounded research record as one contribution to the broader molecular-hydrogen evidence base.