Feeding the low-birth-weight infant: II. Effects of taurine and cholesterol supplementation on amino acids and cholesterol.

Plasma and urine concentrations of taurine were consistently lower in preterm infants fed unsupplemented formula than those observed in the infants fed human milk or formulas supplemented with taurine alone or with taurine plus cholesterol. Such supplementation of formula restored plasma and urine concentrations of taurine to those observed in the infants fed human milk. Taurine was the only amino acid that was present at lower concentrations in the infants fed unsupplemented formula than in those fed human milk. The other acidic and neutral amino acids were present in higher concentrations in the formula-fed infants than in the group fed human milk either during the early weeks of the study (serine, glutamine, glycine, alanine, tyrosine, and methionine) or consistently higher during the entire study (threonine, glutamate, citrulline, valine, isoleucine, leucine, and phenylalanine). Supplementation of formula with taurine plus cholesterol did not appear to have any effect on the amino acid concentrations in the plasma and urine, other than that on taurine itself. Plasma total cholesterol concentration decreased during the fifth to the 12th postnatal weeks of life in all feeding groups. It then returned to the concentrations found during the first and third postnatal weeks in all feeding groups except in the infants fed formulas supplemented with taurine plus cholesterol which had a greater decrease.