No abstract

Pediatr. SummaryW e have recently reported that the intestinal transport of intact macromolecules into the circulation decreases with age presumably due to maturation of mucosal barrier factors. To extend this observation and determine the effect of natural versus artificial feeding on maturation of intestinal mucosal "barrier function," we conducted experiments which assessed both macromolecular transport and epithelial cell morphology.T o study barrier function, we gavage fed a physiologic quantity (100 mg) of bovine serum albumin (BSA) to weight-matched breast-and bottle-fed infant rabbits at 1 and 2 wk of age and quantitated intestinal macromolecular transport by measuring circulating plasma concentrations of the intact antigen 4 hr later.