Bile acid

Bile acids are steroid acids found predominantly in bile of mammals. They are produced in liver by oxidation of cholesterol, in the form of their salts are stored in gallbladder and secreted into the intestine. They act as surfactants, emulsifying lipids and assisting with their digestion and absorption.

Synthesis of bile acids is a major consummer of cholesterol. Body synthetizes about 800 mg of cholesterol per day and about half of that is used for production of bile acids. Total amount of about 20-30 grams of bile acids is secreted into the intestine daily; about 90% of that is reabsorbed and recycled.

The distinction between different bile acids is minute, depends only on presence or absence of hydroxyl groups on positions 3, 7, and 12.

In humans, the most important bile acids are cholic acid and chenodeoxycholic acid, and their conjugates with taurine and glycine (glycocholate and taurocholate). Some other mammals synthetize predominantly deoxycholic acid.

The principal bile acids are:

• Cholic acid
• Chenodeoxycholic acid
• Deoxycholic acid
• Taurocholic acid
• Glycocholic acid