The collection of microbes living in our bodies is known as the microbiome. Interestingly some individuals have gut microbiomes that generate high levels of methane while others produce very little.

According to the study those with high methane-producing microbiomes are particularly efficient at extracting extra energy from fiber-rich foods. This may help explain why calorie absorption from food reaching the colon varies from person to person.

Importantly the researchers emphasize that high-fiber diets are not to blame. In fact people tend to absorb more calories from a Western diet full of processed foods regardless of methane levels. While high-fiber diets result in lower overall calorie absorption the exact amount depends on an individual's methane production.

This difference has significant implications for dietary interventions it highlights that individuals on the same diet may respond in different ways explains Blake Dirks lead author of the study and a graduate researcher at the Biodesign Center for Health Through Microbiomes. Dirks is also pursuing a PhD at ASU’s School of Life Sciences.

A key role of the microbiome is aiding in food digestion. Microbes break down fiber through fermentation producing short-chain fatty acids that the body can use for energy. During this process hydrogen is released. However excessive hydrogen can slow microbial activity unless other microbes step in to consume it.

The human body doesn’t produce methane on its own it’s solely the work of microbes explains Rosy Krajmalnik-Brown the study’s corresponding author and director of the Biodesign Center for Health Through Microbiomes. That’s why we proposed methane could serve as a biomarker for efficient microbial production of short-chain fatty acids.

The study indicates that interactions between gut microbes can influence the body’s metabolism. Researchers discovered that higher levels of methane production were linked to increased creation and absorption of short-chain fatty acids in the gut.

To conduct the study ASU researchers partnered with the AdventHealth Translational Research Institute and used a specialized facility. For six days each participant stayed in a sealed hotel-like environment known as a whole-room calorimeter which precisely measured their metabolic activity and methane emissions.

Source: https://news.asu.edu/20250611-health-and-medicine-your-gut-microbiome-calorie-super-harvester