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 pr otein source in food products, including infant formula. In the current stu dy, the effects of different protein sources in milk formula on the develop ment of intestinal function in artificially reared rats were examined. Methods: Rat pups were artificially reared on casein-whey protein-based. wh ey protein-based, or hydrolyzed whey protein-based mill; formula, and the i ntestinal lactase and maltase activities and the capacity of intestinal imm unoglobulin (Ig)G uptake in these rats during the suckling period were dete rmined. Results: There were no significant differences in the activities of disacch aridases among the three groups. In the rats reared on hydrolyzed whey prot ein milk formula, the plasma and jejunal concentrations of human IgG 2 hour s after intragastric administration of human IgG were significantly lower t han those of rats reared on milk formulas containing native proteins. Conclusions: The present results suggest that the presence of native protei n in milk formula and maternal milk may be important for jejunal IgG uptake in suckling rats and the possibility that the presence or absence of nativ e protein in milk formula can modify some developmental processes of the sm all intestine in suckling animals. (C) 1999 Lippincott Williams & Wilkins, Inc.