Hydrogen Gas Links to Digestive Issues in Japanese Intestinal Disorder
- Authors
- Takanori Igarashi, Kentaro Tominaga, Kunihiko Yokoyama, Takuya Wakabayashi, Yuichi Kojima, Yuzo Kawata, Naruhiro Kimura, Kazuya Takahashi, Akira Sakamaki, Shuji Terai
- Journal
- Cureus
- Year
- 2025
- DOI
- 10.7759/cureus.94054
- Study Type
- Human
- Outcome
- Neutral
- Peer Reviewed
- Yes
- Country
- Japan
- Health Condition
- Chronic Intestinal Pseudo-Obstruction
- Body System
- Digestive
TL;DR
In Japanese patients with chronic intestinal pseudo-obstruction (CIPO), hydrogen-positive SIBO was significantly more prevalent than in healthy controls, while intestinal methanogen overgrowth was rare. These findings highlight the role of hydrogen-producing bacterial overgrowth in CIPO-related symptoms like diarrhea and low BMI.
Key Finding
Hydrogen-producing bacterial overgrowth was found in 50% of Japanese patients with chronic intestinal pseudo-obstruction, compared to 0% in healthy controls.
Summary
This study examined whether people with chronic intestinal pseudo-obstruction (CIPO)—a condition where the intestines don't move food properly—have bacterial overgrowth in the small intestine. Researchers tested 10 CIPO patients and 10 healthy people using a breath test that measures hydrogen gas produced by bacteria. Half of the CIPO patients tested positive for hydrogen-producing bacterial overgrowth, compared to none of the healthy controls. The CIPO patients with bacterial overgrowth also tended to have lower body weight and more diarrhea.
Practical Takeaway
This small study suggests that bacterial overgrowth in the small intestine may be common in people with severe intestinal motility disorders, but the findings are from only 10 patients and should not be generalized widely. The results may eventually help doctors better diagnose and manage these conditions, though larger studies are needed to confirm these patterns.
Abstract
Background: Evidence for small intestinal bacterial overgrowth (SIBO) in chronic intestinal pseudo‑obstruction (CIPO) remains limited in Asian populations and by gas phenotype. This study aimed to determine the prevalence and gas phenotype distribution (hydrogen-positive SIBO vs. intestinal methanogen overgrowth) in Japanese patients with CIPO using glucose breath testing and to describe associated clinical features. Methods: This single‑center cross‑sectional study was conducted at Niigata University, Niigata, Japan (April 2019-March 2022), and included 10 CIPO outpatients and 10 healthy controls. Participants fasted for 12 hours and avoided high-fiber foods for 24 hours before testing. Glucose breath testing (50 g, institutional SOP) measured hydrogen (H₂) and methane (CH₄); positivity followed North American Consensus criteria (ΔH₂ ≥20 ppm by 90 min; CH₄ ≥10 ppm). The primary outcome was hydrogen‑positive SIBO (H₂‑SIBO); intestinal methanogen overgrowth (IMO) was analyzed separately. Exact tests accounted for the small sample size. Results: H₂‑SIBO was more frequent in CIPO than in controls (5/10 vs. 0/10; Fisher two‑sided p = 0.0325; continuity‑corrected OR = 21). Overall SIBO (H₂ or CH₄) was 5/10 vs. 1/10 (p = 0.141, two‑sided). No CIPO patient met IMO criteria; one control was methane‑positive. Among CIPO patients, H₂‑SIBO was associated with lower BMI and a higher frequency of diarrhea. Conclusions: In this small Japanese cohort, CIPO was associated with H₂‑SIBO, whereas IMO was uncommon. These findings should be interpreted with caution due to limited statistical power and potential under-detection of distal overgrowth with glucose substrate. These findings may inform on diagnostic strategies and nutritional management in severe motility disorders.