Interazione tra gli acidi biliari e il microbiota intestinale: implicazioni fisiopatologiche = Reciprocal interactions between bile acids and intestinal microbiota: pathophysiological implications

The microbiota and the genes that comprise its microbiome play a key role in human pathophysiology. Host-microbe interactions affect metabolism, immunity, behavior and development. Alterations in the intestinal microbiota composition are associated with a number of diseases, ranging from obesity and inflammatory diseases to neurodevelopmental disorders and physiological abnormalities. The gut microbiota not only facilitates harvesting of nutrients and energy from the ingested food, but also convert dietary molecules into signaling metabolites to communicate with the host. One such class of metabolites, bile acids, is produced in the liver from enzymatic oxidation of cholesterol and is metabolized in the intestine by the gut microbiota. Bile acids function both as detergents that facilitate digestion and absorption of dietary lipids, and as hormones that act systemically via several receptors and regulate numerous metabolic pathways in the host. Conversely, bile acids can modulate gut microbial composition both directly owing to their detergent properties on bacterial membranes, and indirectly through activation of specific genes in the small intestine. Thus, targeting the interplay between microbiota, bile acids, and bile acid receptors signaling seems to represent a promising avenue for the treatment of metabolic diseases. However, much more research is needed in order to reach a deeper understanding of the complex crosstalk between the gut microbiota and the human host.