Effects of Probiotics on the Immune System and Allergic Diseases

Intestinal microbiota play a crucial role in the development of mucosal tolerance and adaptation. Perturbations in microbiota composition are strongly associated with allergies and asthma in westernized countries. There has been accumulating evidence that the administration of probiotics, “live microbial supplements that exert a beneficial effect on human health,” may be effective in the treatment and/or prevention of allergic diseases. Although it has been shown that part of the effect of probiotics arises from its interaction with the host immune system, the precise mechanisms remain to be determined. In addition, future studies are necessary to define appropriate species and strains, optimum dose, frequency, and duration for the treatment of allergic diseases.