Studies of bile lipids and bile acids of wild North American black bears in Nova Scotia, showing a high content of ursodeoxycholic acid.

Does ursodeoxycholic acid (UDC) production protect hibernating species of Ursidae against gallstone disease? Five wild bears (Ursis Americana) were studied. Older bears had more UDC than younger ones, suggesting UDC production is an acquired phenomena. Bile salt pools were 10 times larger than that of man and were characteristically conjugated with Taurine alone. The relative composition of the principal lipids in bear bile fell well within the range of cholesterol solubility. Cholesterol gallstones are not reported in Ursidae, probably because of the large bile acid pool and high UDC content.