Host immune response to antibiotic perturbation of the microbiota.

Mammals are superorganisms, being a composite of mammalian and microbial cells existing in symbiosis. Although the microbiota is not essential for life, commensal and intestinal epithelial cell interactions are critical for the maturation of the immune system. Antibiotic treatment alters this delicate balance by causing compositional changes in the intestinal microbiota, and may lead to a homeostatic imbalance through alterations in expression of IEC tight junction proteins, mucin, antimicrobial peptides, and cytokines. Dysregulation of the homeostasis between mammals and their intestinal symbionts has been shown to predispose the host to enteric infection, and may lead to development of inflammatory bowel diseases.