The effects of ingestion of hydrogen-dissolved alkaline electrolyzed water on stool consistency and gut microbiota: a double-blind randomized trial

Katsuhiro Koyama, Masataka Kiuchi, Yasuki Higashimura, Yoshinori Tanaka, Yuji Naito

Read more:

DOI: 10.4103/2045-9912.318858 DOI is the universal ID for this study.

This link will take you to the full study.


A relationship between Bifidobacterium and defecation has previously been reported. Our hypothesis on the effectiveness of alkaline electrolyzed water (AEW) proposes that ingestion of AEW, considered possessing antioxidative properties, increases the number of Bifidobacteria and improves stool hardness and gastrointestinal symptoms. A double-blind, randomized study was conducted to evaluate the connection between stool consistency and change in gut microbiota composition induced by drinking hydrogen-dissolved AEW. The participants drank 500 mL of purified tap water or AEW every day for 2 weeks. In this study, drinking AEW did not drastically change gut microbiota, but it appeared to act on a specific bacterial species. Drinking AEW was confirmed to cause an increase in Bifidobacterium. The AEW group also saw stool consistency significantly converge to Bristol stool scale Type 4 ('normal'). Therefore, it is highly likely that the gut microbiota will be changed by drinking AEW. This study was retrospectively registered in University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN ID: UMIN000039507) on February 18, 2020, and was approved by the Ethics Committee of University of Yamanashi (approval No. H30-25) on January 9, 2018.

Publish Year 2021
Country Japan
Rank Positive
Journal Medical Gas Research
Primary Topic Intestine
Secondary TopicIndigestion
Model Human
Tertiary TopicGut Microbiome
Vehicle Water (Electrolysis)
pH Alkaline
Application Ingestion