title: Biological and clinical significance of the gut as a barrier to penetration of macromolecules. Practical implications with respect to breast feeding.
abstract: This review stresses the importance of the gut as an immunologic organ, and describes those factors in the gut which impede penetration of potentially harmful macromolecules, particularly the secretory IgA system. Because of the immaturity of this gut function in the young infant, breast feeding should be encouraged for the first six to nine months of life whenever possible.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000941:Antigens; D001402:B-Lymphocytes / Q000276:immunology; D001942:Breast Feeding; D004064:Digestive System / Q000276:immunology*; D004406:Dysgammaglobulinemia / Q000276:immunology; D005260:Female; D006801:Humans; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007223:Infant; D007231:Infant, Newborn; D008198:Lymph Nodes / Q000276:immunology; D008892:Milk / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000941:Antigens; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D007075:Immunoglobulin M