Bile acid pool and bacterial bile acid metabolism

The bile acid pool and bacterial bile acid metabolism constitute a complex physiological system involving the hepatic synthesis of primary bile acids and their subsequent biotransformation by gut microbiota into secondary bile acids (Wahlström et al., 2016, Cell Metabolism). This system is fundamental for the emulsification of dietary lipids and serves as a critical signaling hub through the activation of the Farnesoid X Receptor (FXR) and the G protein-coupled bile acid receptor 1 (TGR5) (Fiorucci & Distrutti, 2019, Trends in Molecular Medicine). Dysregulation of bile acid homeostasis is a hallmark of cholestatic liver diseases, such as primary biliary cholangitis, and is increasingly linked to metabolic syndrome and inflammatory bowel disease (Trauner et al., 2017, Gastroenterology). Therapeutic strategies targeting this system include the use of bile acid sequestrants to lower cholesterol, FXR agonists to reduce bile acid synthesis, and apical sodium-dependent bile acid transporter (ASBT) inhibitors to interrupt enterohepatic circulation (Karpen & Dawson, 2015, Journal of Lipid Research). These interventions aim to mitigate the toxic effects of accumulated bile acids and modulate systemic metabolism through the gut-liver axis (Ridlon et al., 2014, Current Opinion in Gastroenterology).

Other names

Enterohepatic circulation of bile acidsGut microbiota-bile acid axisBile acid signaling pathwayBile acid homeostasis

Modulation of the bile acid pool size, composition, and signaling through the activation of nuclear receptors (FXR) and membrane receptors (TGR5), inhibition of intestinal transporters (ASBT), or physical sequestration of bile acids to interrupt enterohepatic circulation.