Bile salts facilitate digestion of fat in the intestine by being emulsifying agents. They lower the surface tension of water and emulsify the fats, where it is exposed to the action of pancreatic lipase. In intestine, bile acids combine with mono and digycerides to form tiny particles called micelles, which are about 1/100th of size of usual emulsified triglyceride particle, which facilitates absorption of fat. Bile salts activate pancreatic lipase and cholesterol esterase. They facilitate absorption of cholesterol and fat-soluble vitamins. Bile salts act as stimuli to the secretion of hepatic bile. Bile salts help in maintaining cholesterol level in bile. When ratio of bile acid to cholesterol decreases, cholesterol gets precipitated and forms gall stones.