Beyond emulsification, how do bile salts aid lipid digestion?

Beyond emulsification, how do bile salts aid lipid digestion?

• A. They do not participate beyond emulsification and are excreted unchanged in feces.
• B. They bind to lipids and block pancreatic lipase activity.
• C. They form micelles with fatty acids and monoglycerides, increasing surface area for pancreatic lipase; absorbed in the ileum.
• D. They are absorbed as free fatty acids into enterocytes and bypass micelle formation.

Answer: (C)

Bile salts do more than just break fat into droplets; they form mixed micelles with fatty acids and monoglycerides. These micelles keep lipids dissolved in the watery intestinal environment and bring the digestion products right to the brush border. Pancreatic lipase digests triglycerides, and the resulting fatty acids and monoglycerides stay within these micelles, which increases their accessibility to the enterocytes. At the intestinal lining, the lipids diffuse into cells, are re-esterified, and then packaged for transport. The micelles also help deliver lipids efficiently to the absorptive surface, enhancing uptake. Afterward, bile salts are reabsorbed mainly in the ileum and recycled to the liver. So, their role extends to solubilizing and delivering lipid digestion products, not just emulsifying them. They are not excreted unchanged, they do not block lipase, and they are not absorbed as free fatty acids bypassing micelle formation.

Bile salts do more than just break fat into droplets; they form mixed micelles with fatty acids and monoglycerides. These micelles keep lipids dissolved in the watery intestinal environment and bring the digestion products right to the brush border. Pancreatic lipase digests triglycerides, and the resulting fatty acids and monoglycerides stay within these micelles, which increases their accessibility to the enterocytes. At the intestinal lining, the lipids diffuse into cells, are re-esterified, and then packaged for transport. The micelles also help deliver lipids efficiently to the absorptive surface, enhancing uptake. Afterward, bile salts are reabsorbed mainly in the ileum and recycled to the liver. So, their role extends to solubilizing and delivering lipid digestion products, not just emulsifying them. They are not excreted unchanged, they do not block lipase, and they are not absorbed as free fatty acids bypassing micelle formation.