What Is the Role of Bile in Digestion?

Bile in the digestive system exists primarily to facilitate fat absorption in the small intestine, and then send digested fats elsewhere in the body. Although the small intestine is the central area of bile activity, bile is created in specialized cells called hepatocytes, which are found in the liver. The quantity of bile produced following ingestion of food depends on the type and volume of food that enters the digestive system.

Bile production begins in bile channels, also called canaliculi. The process begins upon ingestion of food that, in turn, signals the digestive system to begin working. Most bile is formed in liver cells, and the volume and rate of bile production depends on the rate at which bile-forming acids are released into bile channels. Although the quantity of bile produced varies slightly among individuals, approximately 3 grams of the viscous digestive fluid are created at a time.

Bile production is triggered through a complex process, which begins with the activation and production of certain chemicals and hormones. Before producing bile, liver cells create sodium, which in turn determines the quantity of bile produced. Bile generation is also controlled by the actions of intestinal hormones, such as secretin, gastrin and CCK. These elements work together to create a thick, viscous substance (bile), which is then diluted with water.