INFLUENCE OF CASEIN AND CASEIN HYDROLYSATE DIETS ON NUTRITIONAL RECOVERY OF STARVED RATS

Background: The aim of this study was to compare the effects of two di ets, which differed in their protein source (casein and casein hydroly sate), on the nutritional recovery and intestinal repair of undernouri shed rats at weaning after a 3-day fasting period. Profound alteration s in gut structure and signs of malnutrition appeared after the starva tion period. Methods: The casein hydrolysate was prepared by enzymatic hydrolysis and ultrafiltration. Rats were refed the casein-based or t he casein hydrolysate-based diet for 96 hours. Normal-fed male Wistar rats at weaning were given the casein diet for 7 days and were used as controls. Liver acetylcholinesterase, glutamate dehydrogenase activit ies, serum amino acid profiles, jejunal oligosaccharidases, alkaline p hosphatase, and leucine aminopeptidase activities were studied. Intest inal permeability to intact proteins was also tested by using ovalbumi n and measuring its concentration in serum. Results: Intestinal and li ver enzyme activities and serum amino acid profiles reached normal val ues after 96 hours of refeeding, regardless of the diet used. Glutamat e dehydrogenase activity remained higher in both diet groups. Intestin al permeability to ovalbumin remained significantly increased only in the group refed the casein diet. Conclusions: Our results show that 4 days of refeeding are sufficient for complete intestinal recovery afte r fasting, provided the dietary protein source is a casein hydrolysate . We suggest that patients with malnutrition or malabsorption syndrome should be fed formula composed of enzymatic protein hydrolysates (bec ause of their low antigenicity) rather than enteral formulas composed of intact proteins.