ENTERAL NUTRITION MODIFIES GUT-ASSOCIATED LYMPHOID-TISSUE IN RAT REGARDLESS OF THE MOLECULAR-FORM OF NITROGEN SUPPLY

Background: It has been suggested that beneficial effect of elemental enteral diets in the treatment of inflammatory bowel diseases could be mediated by the suppression of protein dietary antigens. The objectiv e of the present work was to study the effect of enteral diet on gut a ssociated lymphoid tissue and on gastric Lactobacillus flora, in rat. Methods: The effects of three molecular forms of nitrogen supply: amin oacids, oligopeptides or whole casein, were compared in rats on contin uous enteral diet. Frozen sections of small bowel were studied with mo noclonal antibodies anti-CD5, -CD4, -CD8, -CD25, -macrophages, -MHC II . The Lactobacillus flora was also enumerated in the stomach, in order to assess the effect of ED on rat flora. Results: Growth and mucosa m orphology were identical in control and enteral groups. Rats on entera l diet showed, whatever was the molecular form of nitrogen supply, a d ecrease in CD5+, CD4+ and CD8+ intraepithelial cell numbers, but not i n lamina propria cell number, and a decreased MHC II epithelial expres sion, when compared to control rats. The enterally fed rats also showe d a decrease in Lactobacillus gastric contents. Conclusions: The curre nt study demonstrates that continuous enteral nutrition modifies MHC I I epithelial expression and gut associated lymphoid tissue cell number in rat, whatever is the molecular form of nitrogen supply. Intestinal flora could be responsible, at least for part, for these results. (C) 1997 Lippincott-Raven Publishers.