GLYCOCONJUGATES OF THE TROUT AND SOLE INTESTINAL MUCOSA FOLLOWING IN VITRO EXPOSURE TO PROBIOTIC BACTERIA

Probiotic bacteria are known to exert several beneficial effects such as nutritional contribution and protection against pathogens, either by the production of antimicrobial compounds or through competition for mucosa binding sites. Their effect on development and/or activation of beneficial immune responses in the host is widely recognized although not fully clarified. The use of probiotics has been applied in human and animal nutrition with successful results. In order to investigate a possible relation between probiotic bacteria and glycosylation pattern expressed by the intestinal mucosa, we studied the binding patterns of several lectins in the lining epithelium of trout and sole intestine exposed to differently modified microbiotica environment. Three experimental treatments were realized by in vitro exposure of fish intestines to probiotic bacteria (L. rhamnosus, and L. paracasei, group 1), pathogen bacteria (V. anguillarum, group 2), probiotic bacteria followed by pathogens (group 3). In the control group (group 4), the intestines were exposed to sterile saline solution and TSBgs in the same conditions, as above. The preliminary results indicate that the exposure of the sole intestine to probiotic bacteria affects the lectin binding patterns of specific sugar residues and modulates the effect induced by exposure to the pathogens. In the trout intestinal mucosa, interesting data were also obtained accounting for a relation between probiotics and modified expression pattern of the ladderlectin and intelectin, both proposed to function in mucosal and cellular innate immune defence against microrganisms.