Two bile acids that are naturally produced by the body may help reduce the amount of fat absorbed by the liver, according to new University of California, Berkeley research. Fatty liver disease is common in people who are obese and contributes to insulin resistance in people with type 2 diabetes. Understanding how these substances can slow or block the development of fatty liver disease may lead to new treatments. Bile acids are produced when the body breaks down cholesterol and helps to eliminate extra cholesterol and absorb dietary fat. The researchers tested more than 30 different bile acids before finding two, ursodeoxycholic acid (UDCA), also known as “bear bile acid,” and deoxycholic acid (DCA), that appear to inhibit liver-specific transporter proteins that carry fatty acids into the liver. In studies with mice, those eating high-fat diets that were treated with either UDCA or DCA showed lower accumulations of fat in their livers than mice in a control group. In addition, the researchers found that DCA interacts with bacteria in the gut, which also may contribute to how much dietary fat is absorbed by the liver. The researchers plan to test whether UDCA and DCA can prevent type 2 diabetes in animal studies.