Intestinal cholesterol in bile salt micelles

Intestinal cholesterol in bile salt micelles represents a critical physiological complex required for the absorption of dietary and biliary cholesterol within the small intestine. Bile salts, synthesized from cholesterol in the liver, are secreted into the intestinal lumen where they aggregate to form mixed micelles (StatPearls, 2023). These micelles act as transport vehicles, solubilizing hydrophobic cholesterol molecules and facilitating their diffusion across the unstirred water layer to the enterocyte surface (Hofmann, 1999). This process is a fundamental step in lipid metabolism and a key determinant of systemic cholesterol levels. In the context of pharmacology, this micellar complex is a target for lipid-lowering therapies. Plant sterols and stanols function by competitively displacing cholesterol from these micelles, thereby reducing the amount of cholesterol available for uptake by the Niemann-Pick C1-Like 1 (NPC1L1) transporter (Trautwein et al., 2003). Similarly, bile acid sequestrants disrupt this process by binding to bile salts, which prevents the formation of micelles and leads to the fecal excretion of both bile acids and cholesterol (DrugBank, 2024). Consequently, targeting the stability and composition of these micelles is an effective strategy for managing hypercholesterolemia and reducing the risk of cardiovascular disease.

Other names

Mixed micellesBile acid-cholesterol micellesIntestinal lipid micellesBiliary micelles

Competitive displacement of cholesterol from micelles; Sequestration of bile acids to prevent micelle formation