EFFECT OF INDIGESTIBLE SACCHARIDES ON B-LYMPHOCYTE RESPONSE OF INTESTINAL-MUCOSA AND CECAL FERMENTATION IN RATS

The effects of water-soluble and -insoluble indigestible saccharides ( IDS) on immune responses of the intestinal tract were studied. Male 4- week-old Sprague Dawley rats were fed for three weeks on diets contain ing several kinds of IDS at 5%. The results revealed that the proporti on of kappa-light chain and IgA-presenting lymphocytes in small intest inal and cecal mucosa differed in increased number depending on the ty pe of IDS. The response of colonic mucosa was not pronounced. The amou nts of short-chain fatty acid (SCFA) and lactic acid in the cecal cont ents of the other test groups except the celfur group tended to be hig her than those in the cellulose group, particularly in the lactulose g roup where many acids showed significant increases. The correlation be tween the proportion of kappa-light chain and IgA-presenting lymphocyt es in the cecal mucosa and lactic acid in the cecal contents was signi ficant, but that between the proportion of both lymphocytes and SCFA w as not. Based on the above, we concluded that the oral administration of IDS induces the proliferation of kappa-light chain and IGA-producin g B lymphocytes in small intestinal and cecal mucosa, but the degree o f response differs depending on the type of IDS. It is thus suggested that IDS are involved in the intestinal immune system of rats.