Bile acid-cholesterol mixed micelle

Bile acid-cholesterol mixed micelles are supramolecular aggregates formed in the intestinal lumen through the self-assembly of bile salts, phospholipids, and dietary or biliary cholesterol [1]. Their primary biological function is to solubilize hydrophobic lipids, which are otherwise insoluble in the aqueous environment of the gut, facilitating their transport across the unstirred water layer to the enterocyte surface for absorption [1, 3]. These micelles are central to lipid metabolism, as they determine the efficiency of cholesterol and fat-soluble vitamin uptake [1]. In clinical medicine, they are significant targets for treating hypercholesterolemia and reducing cardiovascular risk [2]. Elevated cholesterol absorption via these micelles contributes significantly to the development of atherosclerosis [2, 4]. Pharmacological agents like plant sterols (e.g., beta-sitosterol) target these micelles by competitively displacing cholesterol from the micellar core, thereby reducing its bioavailability for absorption [2]. Additionally, bile acid sequestrants disrupt the formation of these micelles by binding and removing bile acids from the intestinal pool [4]. Other drugs, such as ezetimibe, indirectly interact with this system by inhibiting the protein-mediated uptake of cholesterol specifically from the micellar phase into the intestinal wall [5]. Understanding the physical chemistry of these micelles is essential for developing therapies that manage lipid levels and prevent cardiovascular disease [1]. Sources: [1] Wang, D. Q. (2007) Frontiers in Bioscience; [2] Trautwein, E. A., et al. (2003) Eur. J. Lipid Sci. Technol.; [3] Phan, T. K., et al. (2013) J. Phys. Chem. B; [4] StatPearls (2023) Bile Acid Sequestrants; [5] PubChem (2024) Ezetimibe.

Other names

Intestinal mixed micelleBile salt-lipid micelleMixed lipid micelleBile acid micelle

Competitive displacement of cholesterol from the micellar core by plant sterols; Sequestration of bile acid components to prevent micelle assembly; Inhibition of cholesterol transfer from the micelle to the enterocyte brush border.