Lactic acid bacteria, probiotics and immune system [Review]

This review article summarizes beneficial effects of lactic acid bacteria (LAB) colonizing the gastrointestinal tract. Probiotic microorganisms including LAB positively influence the composition of the gut microflora; they stimulate the production of secretory IgA, they affect the targeted transportation of the luminal antigens to Peyer's patches and they increase the production of IFN-gamma. LAB stimulate local and systemic immune responses as well as the activity of non-specific and specific immune cells, they are also able to eliminate damage to the gut microenvironment and maintain the integrity of the gut wall. These properties depend on the particular species or strain of bacteria and are singularities are probably determined by differences in the cell wall composition.