• Bile acids are predominantly made up of cholic acid and chenodeoxycholic acid.
• Primary bile acids are derived from cholesterol in the liver.
• Bile acids are conjugated in the liver with taurine or glycine and are excreted in bile via the bile duct as their sodium salts (bile salts).
• Bile acids are secreted at time of eating to small intestine where they aid in digestion and absorption of fat and fat-soluble vitamins.
• Bile acids are reabsorbed from the gastrointestinal tract into the circulation.  They are transported to the liver to be re-secreted in the bile.
• Bile acids are a sensitive indicator of liver function and of integrity of liver, biliary and intestinal circulation.
• Fasting is particularly important when determining serum bile acids levels.

Uses

Alone

• In other species:
  • Bile acids are used as an assessment of liver function.
  • Measurement can aid in the diagnosis of a portosystemic shunt.
  • A bile acid stimulation test is an even more sensitive test for liver function than fasted bile acids.
  • Overall, a single value is not enough to determine pathology. Values are normally elevated after feeding.

In combination

• Combined with other liver enzymes to properly assess liver function.