Any role for probiotics in the therapy or prevention of autoimmune diseases? Up-to-date review.

Probiotic use as capable preventive and therapeutic strategy in different diseases varying from allergic to autoimmune disease (AD) has been recently reported. Three interacting factors including an aberrant intestinal microbiota, a "leaky" intestinal mucosal barrier, and altered intestinal immune responsiveness have been suggested to be able to create a "perfect environment" for AD development. Regulation of intestinal microflora composition by probiotics offers the possibility to influence the development of mucosal/systemic immunity besides ADs. Moreover, with various strains of probiotics, development and/or stimulation of T helper type 2 (Th2)-mediated immune responses causing exacerbation of atopic disease have been described. Similarly, certain probiotics are known to stimulate Th1 immunity, which has been suggested as one of the mechanisms by which they can suppress Th2-mediated allergic diseases. Consequently, this presumed that excessive immunostimulation might aggravate or induce Th1-mediated immune responses and diseases such as type 1 diabetes, multiple sclerosis, and it might cause an additional safety issue. Although there is a large amount of conflicting data on the preventive/therapeutic effects of probiotics in ADs, there is fairly promising evidence to recommend as well. Thus, probiotic use cannot be generally recommended for primary prevention and therapy of ADs for now.