Bile acids and bile salts (BA) (BA)

Bile acids and bile salts are amphipathic steroid molecules synthesized from cholesterol in the liver and secreted into the intestinal lumen [NIH, 2022]. Their primary biological function is to facilitate the emulsification and absorption of dietary lipids and fat-soluble vitamins by forming mixed micelles [StatPearls, 2023]. Beyond digestion, they act as potent signaling molecules that regulate glucose and lipid metabolism through receptors like the Farnesoid X Receptor (FXR) and TGR5 [Nature Reviews, 2017]. In the context of pharmacology, luminal bile acids are the direct target of bile acid sequestrants, which are non-absorbable polymers that bind these molecules in the gut [PubChem, 2023]. This binding prevents their reabsorption in the terminal ileum, interrupting the enterohepatic circulation and forcing the liver to convert more cholesterol into bile acids, thereby lowering systemic LDL cholesterol levels [StatPearls, 2023]. Additionally, modulating the bile acid pool in the lumen is a therapeutic strategy for treating bile acid malabsorption, chronic diarrhea, and cholestatic pruritus [Mayo Clinic, 2023]. Recent research also highlights their role in modulating the gut microbiome and metabolic health in conditions like type 2 diabetes [Journal of Lipid Research, 2021].

Other names

Bile saltsIntestinal bile acidsLuminal bile acidsBile acid micellesPrimary and secondary bile acids

Bile acid sequestration, interruption of enterohepatic circulation, and induction of hepatic cholesterol-7-alpha-hydroxylase.