August 10th, 2026
Researchers here discuss a bidirectional relationship between age-related alterations in bile acid metabolism, centered in the liver, and changes in the composition of the gut microbiome. These changes take place in the context of increasing dsyfunction of the intestinal barrier with age, allowing unwanted bacteria and bacterial metabolites into the body to provoke chronic inflammation and other dysfunction. Researchers have demonstrated in animal studies that restoration of a youthful gut microbiome composition can improve health and extend life; an interesting question is the degree to which restoration of a youthful bile acid metabolism can achieve similar outcomes.
Bile acids (BAs), byproducts of cholesterol metabolism in the liver, are not only vital for lipid digestion and absorption of lipid-soluble vitamins but also act as signaling molecules influencing aging, inflammation control, immune homeostasis, and tumor development. They regulate gut microbiota growth and composition, while gut microbiota significantly influence BA hydrolysis and the synthesis of secondary and tertiary BAs. This interplay affects immune function and metabolic phenotypes, and may contribute to obesity, diabetes, non-alcoholic fatty liver disease, inflammatory bowel disease, and certain cancers.
