In the realm of gut microbes, there is a unique group that produces methane, which has been found to influence the absorption of calories from food, particularly in high-fiber diets. A recent study conducted by Arizona State University sheds light on this phenomenon.

The collection of microbes residing in the gut is known as the microbiome. Individuals with gut microbiomes that produce significant amounts of methane tend to extract extra energy from high-fiber diets. This discovery may elucidate why different people derive varying calorie amounts from food that reaches the colon.

It is important to note that high-fiber diets are not to blame. Overall, individuals absorb more calories from processed Western diets, irrespective of methane production levels. On a high-fiber diet, the total calorie absorption decreases, but the extent varies based on methane production.

The insights gained from this study could pave the way for personalized nutrition plans. Lead author Blake Dirks, a graduate researcher at the Biodesign Center for Health Through Microbiomes, emphasizes the significance of these findings in understanding how individuals respond differently to the same diet due to variations in their gut microbiomes.

The study, published in The ISME Journal, highlights the association between methane-producing microbes, known as methanogens, and enhanced energy absorption from food. The researchers suggest that methanogens may have a symbiotic relationship with other microbes that produce short-chain fatty acids, although further research is needed to confirm this hypothesis.

According to ASU graduate researcher Blake Dirks, methanogens may have played a crucial role in the survival of ancient humans by ensuring efficient energy extraction from their diets rich in whole foods. The microbiome's primary function is to aid in food digestion, converting fiber into short-chain fatty acids that the body can utilize for energy.

Methanogens consume hydrogen during this process, producing methane as a byproduct. This unique ability to generate methane distinguishes them from other microbes involved in the fermentation process.

The research indicates that these microbial interactions impact the body's metabolism, with higher methane production correlating with increased production and absorption of short-chain fatty acids in the gut.

The study involved providing participants with two distinct diets, one rich in processed foods and low in fiber, and the other high in whole foods and fiber. By utilizing a whole-room calorimeter, researchers were able to measure participants' metabolism and methane output continuously over a six-day period.

Data from blood and stool samples revealed the energy absorption efficiency and microbial activity in participants' guts, with comparisons drawn between individuals with high and low methane-producing gut microbiomes.

While most participants absorbed fewer calories on the high-fiber diet compared to the processed-food diet, those with higher methane production levels absorbed more calories from the high-fiber diet than those with lower methane production.

This study lays the groundwork for future research and potential medical interventions to target personalized nutrition plans based on an individual's gut microbiome composition.