The purpose of this investigation is to evaluate the impact of non-persistent and persistent chemical exposures on autoimmunity, gene expression and the microbiome in children with and without Crohn’s disease. If these chemical exposures are associated with differences in the epigenome and microbiome that are known to predispose for Crohn’s disease, the proposed research could further support changes in dietary behaviors to limit exposure, and efforts to regulate manufacturing processes that unintentionally and intentionally add these chemicals to food.