Effect of small doses of deoxycholic acid on bile cholesterol saturation in patients with liver cirrhosis

To test the hypothesis that the detergent power of each individual bile acid--that is, its separate capacity to solubilize cholesterol and to induce biliary cholesterol secretion, present in the biliary bile acid mixture might be one of the determinant factors of biliary cholesterol saturation, we studied the effect of feeding small doses of deoxycholic acid on biliary cholesterol saturation in patients with liver cirrhosis and low deoxycholic acid pool. Eleven hospitalised patients with cirrhosis of various degree of severity were put on a standard solid diet. Fasting bile rich duodenal fluid was obtained at the beginning of the study, after a three to four weeks treatment with deoxycholic acid (3 mg/kg/day, in two doses) and one month after discontinuing bile acid ingestion. Before treatment the fraction of deoxycholic acid was 5.3 +/- 4.9% (mean +/- SD); after treatment the fraction rose to 43.9 +/- 12.0 of total bile acids, but returned to the basal values after stopping bile acids. Bile cholesterol saturation increased significantly from a mean of 0.92 +/- 0.26 (before treatment) to a mean of 1.34 +/- 0.34 after deoxycholic acid feeding (p less than 0.005). One month after treatment, bile saturation was not significantly different from the basal values (0.91 +/- 0.44). We conclude that feeding low doses of deoxycholic acid to patients with liver cirrhosis induces a significant increase of the fraction of this bile acid in the total pool and this is followed by a sharp increase of bile cholesterol saturation. These data are compatible with the hypothesis that the detergent capacity of individual bile acids is one of the main determinants of bile cholesterol saturation.