If a person is suffering from liver and gallbladder problems, the nutrient most hindered in digestion would be lipids. Fats cannot be dissolved in water and bile is essential to their absorption through the intestinal wall because it contains substances which allow fats to be emulsified, and it stimulates secretion of an enzyme which breaks down the fats (Gall). Bile contains water, electrolytes and organic molecules which include bile acids, cholesterol, phospholipids and bilirubin which flow through the biliary tract and into the small intestine to aid digestion (Secretion). Bile acids are critically important for the digestion and absorption of fats and fat-soluble vitamins in the small intestine.
Hepatocytes in the liver produce bile and secrete it into bile canaliculi, from which it flows to bile ducts (Bailey/Secretion). Hepatic bile consists of bile acids, cholesterol and other organic molecules. Bile is modified as it flows through the bile ducts by addition of a watery, bicarbonate-rich secretion from bile duct epithelial cells. Free cholesterol is eliminated this way by being made soluble by the bile acids and lipids like lecithin. Bile acids are derivatives of cholesterol from the diet and that produced by hepatocytes. They consist of cholic and chinodeoxycholic acids which are conjugated to the amino acids glycine or laurine and are then actively secreted into the canaliculi. Bile acids are amphipathic, which allows them to have a detergent action on dietary fat to break down the globules or emulsify them into minute droplets, greatly increasing the surface area of fats and making them available to digestion by lipases. Bile acids are able to solubilize many lipids by forming micelles of fatty acids, cholesterol and monoglycerides. It has been shown that bile acids contribute to cholesterol metabolism by functioning as hormones that alter the transcription of the rate-limiting enzyme in cholesterol biosyn...