Bile acid and cholesterol metabolic pathways

Bile acid and cholesterol metabolic pathways represent the integrated physiological systems responsible for the synthesis, transport, and elimination of sterols within the body. Cholesterol is primarily metabolized in the liver into bile acids through the classical and alternative pathways, involving enzymes such as cholesterol 7-alpha-hydroxylase (CYP7A1) (StatPearls: Cholesterol Metabolism, 2023). These bile acids are essential for the emulsification and absorption of dietary lipids and fat-soluble vitamins in the small intestine. Beyond digestion, bile acids act as signaling molecules by binding to the Farnesoid X Receptor (FXR) and the G protein-coupled bile acid receptor (TGR5), thereby regulating glucose, lipid, and energy homeostasis (PubMed: 28214276). Disruptions in these pathways are linked to various pathologies, including hypercholesterolemia, atherosclerosis, and cholestatic liver diseases such as primary biliary cholangitis (NIH: LiverTox, 2021). Pharmacological interventions often target specific components of these pathways, such as using bile acid sequestrants to lower LDL cholesterol or FXR agonists like obeticholic acid to treat liver disease (PubChem: Obeticholic acid).

Other names

Cholesterol metabolismBile acid metabolismEnterohepatic circulationSterol handling pathwaysBile acid signaling

Modulation of bile acid and cholesterol levels through sequestration in the gut, inhibition of hepatic synthesis, or activation of regulatory nuclear and membrane-bound receptors.