Probiotics and allergic diseases

Abstract

Environmental factors that change microbial composition may contribute to a rapid increase in the prevalence of allergic diseases. Alterations in microbial composition early in life may change immune responses, promoting development of allergic diseases. Probiotics play a role in the regulation of immune homeostasis through the enhancement of intestinal epithelial function and modulation of immune responses. Probiotics regulate immune responses by promoting the differentiation and maturation of dendritic cells, by promoting the development of regulatory T cells, and by inhibiting T helper type (Th)-2 cell responses with increases in Th1 and Th17 cell responses. Several studies have investigated the effects of probiotics for the prevention and treatment of allergic diseases. Many studies have demonstrated that probiotics might be effective for the prevention and treatment of atopic dermatitis. However, there is insufficient evidence to suggest a role for probiotics in the prevention and treatment of food allergy, asthma and allergic rhinitis. The effects of probiotics for the prevention and treatment of allergic diseases in children remain controversial because of variations in study design, differences in probiotic strains, short follow-up periods, and differences in host factors. Well-designed largescale, long-term prospective studies and studies on the mechanisms of probiotics in allergic diseases are needed.