A recent paper in
Current Issues in Molecular Biology reviews the Immunomodulatory Effects of Probiotics in the Intestinal Tract.
The immune system of mammals includes a complex array of cells and molecules which interact to provide protection from challenge by pathogenic microbes (bacteria, viruses, parasites). As most antigens penetrate the body through the mucosa, the mucosal immune system of the host plays a key role in the defense response to pathogens.
The intestinal microbiota is the largest source of microbial stimulation that exerts both harmful and beneficial effects on human health. It acts as a primary agent as it participates in the development of the postnatal immune system as well as oral tolerance and immunity. It is possible that the microbiota acquired during and immediately after birth is necessary for the newborn’s systemic and mucosal immunity and it may also be responsible for controlling inflammatory responses in allergic and inflammatory bowel diseases. If so, probiotics might impede these inflammatory processes by stabilizing the intestinal microbial environment and intestinal permeability barrier by fostering the degradation of enteric antigens and altering their immunogenicity. Immunostimulation and immunomodulation are the leading proposed explanations for the action of probiotics against bacterial pathogens.
The recent paper by Delcenserie et al (2008) briefly describes the innate and adaptive immune system and the mucosal immune system. It then focuses on the interactions between probiotics and the intestinal epithelium and the impact in innate and adaptive immunity and more particularly on the Th1/Th2 balance. The in vitro tests showing the cytokine profile of probiotic strains are described and clinical studies evaluating the effects of probiotics in the treatment of several chronic inflammatory diseases and allergies are reported.
Delcenserie et al (2008) Immunomodulatory Effects of Probiotics in the Intestinal Tract. Curr. Issues Mol. Biol. 10: 37-54
Download the full article (pdf)