TOPLINE

Healthy adults with poor sleep quality who consumed hydrogen-rich jelly for 8 weeks showed improvements in subjective sleep measures in both treatment and placebo groups, with no significant between-group differences in the overall analysis. However, exploratory microbiome analyses revealed that participants in the hydrogen group with lower baseline abundance of hydrogen-producing gut bacteria experienced greater improvements in sleep quality and mental stress.

METHODOLOGY

• A randomized, placebo-controlled trial enrolled 44 healthy adults aged 20-75 years in Japan who were not satisfied with their sleep quality, with average Oguri–Shirakawa–Azumi Sleep Inventory for Middle-Aged and Aged (OSA-MA) scores below 45. 
• Participants were randomly assigned 1:1 to receive either hydrogen-rich jelly (0.9 mg hydrogen daily in 3 doses) or placebo jelly for 8 weeks. 
• The primary outcome was change in OSA-MA score; secondary outcomes included visual analog scale (VAS) scores for sleep quality, mental stress, and physical fatigue, Pittsburgh Sleep Quality Index (PSQI), State-Trait Anxiety Inventory (STAI), oxidative stress markers, and gut microbiome composition assessed via 16S rRNA amplicon sequencing. 
• Gut microbiota beta-diversity was analyzed, and interactions between treatment groups and baseline abundance of hydrogen-producing bacteria were evaluated. 

TAKEAWAY

• The within-group OSA-MA scores and other subjective sleep measures improved significantly from baseline in both the placebo and hydrogen groups over 8 weeks. However, no significant between-group differences were observed in changes in OSA-MA, VAS, PSQI, or STAI scores in the overall analysis. 
• Gut microbiota beta-diversity showed distinct clustering by improvement status in the hydrogen group) but not in the placebo group, with significant differences between improved and not-improved subgroups. 
• Linear mixed-effects model analyses revealed significant interaction between group and hydrogen-producing bacteria for VAS score for sleep quality (P = .008), VAS score for mental stress (P =.005), and OSA-MA Factor 2 (initiation and maintenance of sleep, P =.012). 
• Pearson correlation analyses in the hydrogen group showed that lower baseline abundance of hydrogen-producing bacteria was associated with greater reduction in VAS scores for sleep quality (P =.033) and mental stress (P =.063), with no correlation observed in the placebo group. .

IN PRACTICE

"[W]hile the overall between-group analysis did not demonstrate statistically significant differences in the primary sleep outcomes, our findings suggest that considering gut microbiota composition may help clarify inter-individual variability in response to hydrogen supplementation and that this microbiome-informed stratification approach could be relevant beyond sleep-related outcomes," the authors of the study wrote.

SOURCE

The study was led by Fumiko Higashikawa, Medical Center for Translational and Clinical Research, Hiroshima University Hospital in Hiroshima, Japan. It was published online on July 27 in Scientific Reports.
 

LIMITATIONS

The sample size was relatively small and the participants were mostly from similar racial backgrounds, thereby limiting generalizability. The background diet of participants was not comprehensively characterized, and its possible impact on gut microbiota composition and sleep outcomes cannot be excluded. Those with recent antibiotic use were not excluded, and lasting effects of past antibiotic exposure on gut microbiota composition cannot be ruled out.

DISCLOSURES

The study was funded by Shinryo Corporation, which also provided the experimental jellies. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.