Evidence for amino acid induced cholestasis in very-low-birth-weight infants with increasing enteral protein intake.

In the present investigation 32 very-low-birth-weight (VLBW) infants fed at three different levels of protein intake (2.92 g/kg/d from human milk, 3.22 and 4.06 g/kg/d from formula) were studied at the mean age of 21 days. Serum total alpha-amino nitrogen concentration correlated directly to total bile acid concentration. The serum and urine alpha-amino nitrogen and the serum bile acid concentration correlated with protein intake. The increase in protein intake was accompanied by a concomitant decrease in the intraluminal bile acid concentration in the AGA infants. The results offer indirect evidence of decreased bile flow in VLBW-infants on excessive oral protein intake. The cholestatic effect could be mediated by an increase in the plasma amino acid concentration.