Microbiome and food allergy.

Food allergy is a common disease affecting approximately 8% of children and 5% of adults. The prevalence has increased over the last two decades, suggesting an important environmental contribution to susceptibility. Studies have identified mode of birth, pet exposure, and having older siblings as being significant risk modifying factors in the development of food allergy. With the discovery that these factors significantly impact the composition of the intestinal microbiome, which is known to play a critical role in shaping the immune system, recent studies have begun to address the role of the intestinal microbiota in the development of food allergy. Studies in human cohorts support a dysbiosis in food allergy, and limited data suggest that this dysbiosis occurs early in life, preceding the onset of sensitization. Studies from animal models have clearly shown that the composition of the intestinal microbiota confers susceptibility to food allergy, and that there are organisms such as Clostridia species that are protective in the development of food allergy. Our understanding of microbial regulation of food allergy is in its nascency, but the state of the field supports an important contribution of intestinal microbes to susceptibility. Challenges going forward are to identify commensal-derived microorganisms that could be used therapeutically to prevent or perhaps treat food allergy.