Evaluation of the Development of Intestinal Function in Rats Reared on Hydrolyzed or Native Protein-Based Milk Formula

Background: In recent years, hydrolyzed protein has often been used as a protein source in food products, including infant formula. In the current study, the effects of different protein sources in milk formula on the development of intestinal function in artificially reared rats were examined. Methods: Rat pups were artificially reared on casein-whey protein-based, whey protein-based, or hydrolyzed whey protein-based milk formula, and the intestinal lactase and maltase activities and the capacity of intestinal immunoglobulin (Ig)G uptake in these rats during the suckling period were determined. Results: There were no significant differences in the activities of disaccharidases among the three groups. In the rats reared on hydrolyzed whey protein milk formula, the plasma and jejunal concentrations of human IgG 2 hours after intragastric administration of human IgG were significantly lower than those of rats reared on milk formulas containing native proteins. Conclusions: The present results suggest that the presence of native protein in milk formula and maternal milk may be important for jejunal IgG uptake in suckling rats an the possibility that the presence or absence of native protein in milk formula can modify some developmental processes of the small intestine in suckling animals.