1 beta-hydroxylated bile acids in the urine of healthy neonates

In order to clarify the metabolism of bile acids in neonates, 1 beta-hydroxylated bile acids in the urine of healthy newborns were examined by gas chromatography-mass spectrometry. The results showed that the percentage of total 1 beta-hydroxylated bile acids, 3 beta, 12 alpha-dihydroxy-5-cholenoic acid and hyocholic acid in neonates was significantly higher than in older children. The ratio of 1 beta-hydroxylated bile acids to their comparable primary bile acids was also higher in neonates than in older children. These results suggest that 1 beta- and 6 alpha-hydroxylation of bile acids are the predominant pathways of bile acid metabolism in neonates.