What is the Origin of Bile Acid Transport?

This term is rooted in gastroenterology, hepatology, and lipid biochemistry, describing a core physiological process within the digestive system. The enterohepatic circulation, the system to which it belongs, describes the cycle of secretion, digestion, reabsorption, and return of bile acids from the liver to the small intestine and back.

What is the Mechanism of Bile Acid Transport?

Transport involves specialized carrier proteins, predominantly in the terminal ileum, such as the Apical Sodium-dependent Bile Acid Transporter (ASBT) for uptake and the Organic Solute Transporter (OSTα/β) for basolateral efflux. These transporters ensure that approximately 95% of secreted bile acids are recaptured and returned to the liver via the portal vein. Bile acids also act as signaling molecules, regulating their own synthesis and glucose metabolism through the Farnesoid X Receptor (FXR) and TGR5 pathways, linking this process directly to hormonal and metabolic regulation.

Bile Acid Transport ∞ Area

Bile Acid Transport

Meaning

The highly regulated process of moving bile acids, which are synthesized from cholesterol in the liver, through the enterohepatic circulation to facilitate fat digestion and absorption. This transport mechanism is critical for lipid metabolism and cholesterol homeostasis throughout the body. Clinically, its efficiency directly impacts nutrient assimilation and overall metabolic health.