Dietary amino acid utilization by the gut microbiota in Crohn’s disease.

The gut microbiota is believed to play a critical role in inflammation in Crohn’s disease (CD). Adherent–invasive Escherichia coli (AIEC) often colonize the intestinal mucosa of CD patients. AIEC colonization may promote intestinal inflammation in CD patients. We have found that AIEC prefers to use the amino acid L-serine for growth in the inflamed gut. As dietary proteins are a major source of L-serine in the gut lumen, withholding L-serine from the diet prevents the growth of AIEC in the gut of mice. These facts suggest that a diet deprived of L-serine may alleviate CD symptoms by modulating the gut microbiota, in particular, the colonization by AIEC. In this project, we will validate the effect of dietary L-serine modification on the microbiome and disease outcomes by using a human microbiota–associated mouse model and studying CD patients