Intestinal bile salt and cholesterol micelles

Intestinal bile salt and cholesterol micelles are complex supramolecular aggregates formed in the lumen of the small intestine, primarily composed of bile salts, phospholipids, monoglycerides, and fatty acids [1, 2]. Their primary biological function is to solubilize hydrophobic dietary lipids, such as cholesterol and fat-soluble vitamins, allowing them to traverse the unstirred water layer and reach the intestinal enterocytes for absorption [2]. These micelles are central to lipid metabolism and are a significant focal point in the treatment of hypercholesterolemia and cardiovascular disease [1]. Therapeutic interventions often involve disrupting these micelles or preventing the absorption of their contents. For instance, bile acid sequestrants bind to bile salts to prevent micelle formation and promote fecal excretion [1]. Plant sterols compete with cholesterol for space within the micellar core, reducing its bioavailability [3]. Additionally, drugs like ezetimibe target the transport of cholesterol from these micelles into the enterocyte [4]. By modulating the stability and composition of these micelles, clinicians can effectively lower systemic cholesterol levels and reduce the risk of atherosclerotic plaque formation [1, 4]. References: [1] StatPearls, Bile Acid Sequestrants; [2] StatPearls, Lipid Digestion and Absorption; [3] Journal of Nutrition, Mechanism of action of plant sterols; [4] Clinical Pharmacokinetics, Ezetimibe Review.

Other names

Mixed micellesBile acid micellesIntestinal mixed micellesBile salt-phospholipid-cholesterol aggregates

Bile acid sequestration and inhibition of micellar cholesterol solubilization