# Effects of molecular hydrogen-dissolved alkaline electrolyzed water on intestinal environment in mice.
> アルカリ電解水（水素含有）がマウス腸内環境に与える影響：腸内細菌叢と短鎖脂肪酸の変化


## Abstract

This mouse study examined how 4-week oral administration of alkaline electrolyzed water (AEW) containing dissolved molecular hydrogen influences the intestinal environment. Fecal microbiota profiling via 16S rRNA gene sequencing revealed significant shifts in the relative abundance of 20 bacterial taxa in AEW-administered animals compared with controls. HPLC measurement of cecal organic acids showed elevated concentrations of propionic, isobutyric, and isovaleric acids in the AEW group. Serum low-density lipoprotein cholesterol and alanine aminotransferase activity were both significantly reduced in AEW-administered mice, suggesting favorable effects on lipid metabolism and hepatic function. These findings indicate that dissolved molecular hydrogen may reshape gut microbial communities, with downstream metabolic consequences.

### Mechanism

Because most gut microbial species encode hydrogen-metabolizing genes, dissolved molecular hydrogen from AEW may reshape microbial community composition, altering short-chain fatty acid production and influencing cholesterol metabolism and hepatic enzyme activity.

## Bibliographic

- **Authors**: Higashimura Y, Baba Y, Inoue R, Takagi T, Uchiyama K, Mizushima K, et al.
- **Journal**: Med Gas Res
- **Year**: 2018
- **PMID**: [29770190](https://pubmed.ncbi.nlm.nih.gov/29770190/)
- **DOI**: [10.4103/2045-9912.229597](https://doi.org/10.4103/2045-9912.229597)
- **PMC**: [PMC5937304](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5937304/)
- **Study type**: animal study
- **Delivery route**: hydrogen-rich water
- **Effect reported**: positive

## Delivery context

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 29770190. https://h2-papers.org/en/papers/29770190
> **Source**: PubMed PMID [29770190](https://pubmed.ncbi.nlm.nih.gov/29770190/)