Most of us don’t think much about what happens when we pass gas. But it turns out that a little hydrogen in the mix might actually be a good thing for your gut.
In a new study published in Nature Microbiology, researchers from Monash University and the Hudson Institute of Medical Research discovered that hydrogen gas, long blamed for making farts flammable, plays an essential role in supporting gut health.
“Most people release about a liter of gas per day and half of that is hydrogen,” said Dr. Caitlin Welsh, the study’s lead author. “But hydrogen is more than just the gas behind flatulence — it’s a hidden driver of gut health. … It helps some beneficial bacteria thrive in the gut and keeps digestion going.”
The team found that hydrogen is produced naturally in the gut when bacteria ferment leftover carbohydrates from food. Some of this gas is exhaled, some is reused by other microbes as fuel and the rest exits as flatulence. In healthy guts, this process forms a kind of microbial recycling system that keeps everything in balance.
The study identified a specific enzyme, called Group B [FeFe]-hydrogenase, that helps many gut bacteria make hydrogen. People with healthy guts have plenty of these enzymes, while those with conditions such as Crohn’s disease tend to have fewer of them and more of other, less efficient hydrogen-producing enzymes.
“Gas production in the gut is a normal process,” said Professor Chris Greening, co-senior author from Monash University. “Hydrogen is made in large amounts when gut bacteria break down food and is then used by other microbes for energy.”
Hydrogen levels that are too high or too low, however, can signal problems. Abnormal gas production has been linked to digestive disorders, infections and even cancer. Doctors already use breath tests that measure hydrogen to diagnose some gut conditions.
Understanding how hydrogen shapes the microbiome could lead to better treatments for common digestive issues.
“By understanding the functions of these systems, it opens up new opportunities for therapeutic interventions, some of which we haven’t even considered,” said Associate Professor Sam Forster, co-senior author from the Hudson Institute.
The researchers say this work is a reminder that even something as ordinary, and sometimes embarrassing, as gas plays a vital role in keeping our internal systems running smoothly.
This study was supported by the National Health and Medical Research Council, Australian Research Council, Victorian Government, Swedish Energy Agency, Swedish Research Council, Novo Nordisk Foundation and CSL Centenary Fellowship.