Comparison of patterns of fecal bile acid and neutral sterol between children and adults.

The patterns of bile acids and neutral sterols in the feces of five infants under 1 1/2 years of age, five children 4 years of age, and nine adult subjects without histroy of gastrointestinal diseases were studied by gas-liquid chromatography. Progressive changes in both bile acid and neutral sterol profiles were observed with maturation in infants and children. The patterns in the 4 year olds appraoched those observed in adults. In the infants under 1 1/2 years, cholic and chenodeoxycholic acids constituted 20.7 +/- 4.8% and 7.5 +/- 2.3% of the total bile acid in the stool, respectively. Deoxycholic and lithocholic acids made up only 4.4 +/- 1.7% and 2.9 +/- 1.0%, respectively. In the 4 year olds, the corresponding primary bile acids decreased to 3.9 +/- 1.9% and 5.6 +/- 4.3%, whereas secondary bile acids increased to 21.3 +/- 5.4% and 33.2 +/- 2.2%. Normal adults on regular mixed diets had only small amounts of primary bile acids (2.4 +/- 0.5% and 3.4 +/- 0.6% for cholic and chenodeoxycholic acids). The secondary bile acids in their feces were 34.3 +/- 2.2% and 38.9 +/- 2.0%, respectively. In the neutral sterol fraction, unmodified cholesterol decreased with age: 94.7 +/- 3.7%, 27.0 +/- 1.5% and 25.0 +/- 4.8% of the total neutral sterols in the feces for infants, children, and adults, respectively. On the other hand, coprostanol, the principal metabolite of cholesterol in humans, increased with age: 3.8 +/- 3.4%, 62.6 +/- 3.5% and 65.8 +/- 4.7% for the respective groups. Total bile acid excretion expressed as mg/day, also increased with age: 34 +/- 17, 47 +/- 17 and 293 +/- 69 (for five adult subjects only) for the respective groups. These differences disappeared, however, when the data were expressed as mg/kg of body weight per day: 3.8 +/- 2.0, 3.0 +/- 1.1, and 4.1 +/- 1.0 for the respective groups. Daily excretion of cholesterol metabolites, when expressed as mg/day increased with age: 139 +/- 38, 278 +/- 54 and 719 +/- 211 (for five adult subjects only) for the respective groups. The corresponding values after correction by body weight were 15.4 +/- 4.5, 17.9 +/- 3.0 and 10.3 +/-3.0 mg/kg per day for the respective groups. The production of coprostanol was correlated with 7 alpha-dehydroxylation of cholic acid and chenodeoxycholic acid.