Alterations of serum bile acid profile in breast-fed infants with prolonged jaundice.

Serum bile acid conjugates in breast-fed infants with prolonged jaundice were analyzed by a newly developed procedure using high-performance liquid chromatography with fluorescence labeling. Major bile acids were cholate and chenodeoxycholate conjugates. Some of the breast-fed jaundiced infants had high levels of serum bile acid conjugates (greater than 25 mumol/L), but the mean levels of individual bile acid conjugates found in jaundiced breastfed infants were not significantly different from those in breast-fed infants without jaundice. The glycine- to taurine-conjugated bile acid ratio in breast-fed jaundiced infants was significantly lower than in breast-fed nonjaundiced infants or bottle-fed nonjaundiced infants. In breast-fed infants, the portion of taurine-conjugated bile acids increased in proportion to serum bilirubin levels. These findings suggest that alteration in conjugated bile acid patterns of breast milk jaundice is related to an increased enterohepatic circulation of bile acids as well as bilirubin in infants fed on breast milk that contains high amounts of taurine.