Which best describes the role of bile acids in digestion and how they are recycled?

• A. They emulsify fats to form micelles and are reabsorbed in the ileum via ASBT for enterohepatic circulation.
• B. They digest proteins in the stomach.
• C. They neutralize stomach acid in the duodenum.
• D. They are synthesized in the pancreas.

Answer: (A)

Bile acids act as detergents that emulsify fats, breaking large fat droplets into smaller ones and forming micelles. This increases the surface area for pancreatic lipase to work, allowing efficient digestion and absorption of fatty acids and monoglycerides. After their digestive role, most bile acids are reabsorbed in the terminal ileum via the apical sodium-dependent bile acid transporter, then travel back to the liver through the portal circulation to be reused in a process called enterohepatic circulation. A small amount is lost in the feces, which helps regulate the bile acid pool.

They don’t digest proteins in the stomach—that’s the job of enzymes like pepsin. They don’t neutralize stomach acid; that role is played by bicarbonate and other secretions in the small intestine. And bile acids aren’t synthesized in the pancreas; they’re produced in the liver and stored in the gallbladder before being released into the digestive tract.