Role of Human Milk in the Development of Gastrointestinal Bacterial Flora and Immunity in Preterm Infants

Submit Manuscript | http://medcraveonline.com Hakansson and Molin [4] suggests that microbial colonization of the GI tract affects the composition of GALT. Once the intestine is exposed to microorganisms, intraepithelial lymphocytes increase; germinal centers with immunoglobulin-producing cells arise rapidly in follicles and in the lamina propria and serum immunoglobulin concentrations increase substantially. Hostmicrobe interactions in the gut are well-balanced; secretory IgA, the predominant immunoglobulin found in the intestinal epithelium, is produced by plasma cells in the lamina propria and transported to the lumen by a poly immunoglobulin receptor. Goblet cells in the intestinal epithelium secrete a protective mucus layer, which limits the contact between bacteria and epithelial cells. Paneth cells residing in the crypts of the small intestine secrete bactericidal peptides. Epithelial cells and the mucosal immune system are capable of distinguishing pathogenic and non-pathogenic organisms in the gut. These cells detect bacterial antigens and initiate and regulate both innate and adaptive immune responses [1,7,8].