“Despite increased protein intake in Western diets, particularly among athletes and obese individuals, the fate of undigested protein and its impact on human health remains largely unknown.” On the occasion of the annual meeting of the American Society for Microbiology, a team of researchers shed new light on the effects of a diet rich in protein on the composition of the intestinal microbiota.
Protein diets and gut bacteria
By conducting a series of experiments on mice, scientists at the University of Illinois in Chicago, USA, were able to examine how excess undigested proteins in the colon can ferment and produce beneficial metabolites, such as short-chain fatty acids, or lead to the production of harmful metabolites like ammonia and sulfides, which are linked to gastrointestinal disorders and other health problems. They also confirmed that a protein diet induced significant weight loss and reduced body fat.
To study the effects of such a diet on the bacteria in the gut microbiome, the researchers then conducted a four-week experiment with mice. They received different diets: rich in carbohydrates; standard protein; protein enriched with aromatic amino acids (associated with the greatest weight loss); or protein enriched with branched-chain amino acids for the following two weeks.
The effects of protein amino acids on the gut microbiome
Using fecal samples and body fat measurements, the researchers were able to compare microbial composition across food groups. They found that “protein supplementation led to changes in the abundance and composition of gut bacteria”, according to a press release. Using machine learning techniques, they were able to predict protein diets by 97% based on gut microbial composition. “The most significant alterations occurred in the branched chain amino acid group”they specify.
“These findings provide a crucial basis for understanding how high-protein diets influence the gut microbiome and open the door to further studies on the role of diet in promoting a healthy gut and overall health.”concludes biologist Samson Adejumo, lead author of the research.
