How Your Gut Bacteria Naturally Produce Hydrogen Gas
- Authors
- Michael D. Levitt
- Journal
- New England Journal of Medicine
- Year
- 1969
- DOI
- 10.1056/NEJM196907172810303
- Study Type
- Human
- Outcome
- Neutral
- Peer Reviewed
- Yes
- Country
- United States
- Health Condition
- Small Bowel Bacterial Overgrowth
- Body System
- Gastrointestinal
TL;DR
Scientists found that the human gut produces more hydrogen gas, especially in the colon, when people eat or drink certain sugars like lactose, and some of this gas is breathed out, which can help measure gut activity.
Key Finding
Intestinal hydrogen production in humans is primarily a colonic process driven by bacterial fermentation of carbohydrates, and breath hydrogen levels correlate strongly (r = 0.94) with actual intestinal hydrogen production.
Summary
Researchers studied how much hydrogen gas the human intestine produces by measuring it directly and tracking it in breath. They found that hydrogen production is normally very low when fasting, but increases dramatically after eating, especially after consuming lactose (a sugar in milk). Most hydrogen is produced in the colon (large intestine) by bacteria breaking down food, and about 14% of the hydrogen produced is exhaled in breath, which correlates closely with how much is being made in the gut.
Practical Takeaway
This foundational study explains how hydrogen gas naturally forms in the human digestive system through bacterial fermentation of food. While it establishes that breath hydrogen testing can measure intestinal hydrogen production, this research does not address hydrogen water consumption or its health effects—it simply describes the body's own hydrogen gas production as a normal digestive process.
Abstract
Technics employing intestinal infusions of gas were used to study H2 production in the human intestine. The volume of H2 in the bowel of 10 normal subjects varied from 0.06 to 29 ml. H2 production, which averaged 0.24 ml per minute in the fasting state, sharply increased after intestinal instillation of lactose to a mean peak rate of 1.6 ml per minute. Ingestion of food also increased H2 production by seven-fold to 30-fold. In the normal intestine, more than 99 per cent of H2 production was colonic, but small-bowel production was increased in a patient with excessive numbers of small-bowel bacteria. H2 production in man is primarily dependent upon the delivery of ingested, fermentable substrates to an abundant intestinal flora that normally is present only in the colon. A mean of 14 per cent of the total H2 production was excreted by the lungs, and rates of breath H2 excretion and H2 production correlated well (r = 0.94). Respiratory H2 excretion can therefore be used as an indicator of intestinal H2 production.