Environmental factors, the microbiome (bacteria in our gut) and innate immunity all play a role in the pathogenesis of Crohn's disease .Exclusive enteral nutrition (EEN) was found to be effective for inducing remission in active pediatric Crohn's disease, while Partial Enteral Nutrition (PEN) with free diet was not; suggesting that the mechanism of EEN depends on exclusion of dietary components. Dietary factors may play a role in the pathogenesis of the disease, and maybe an important under-investigated therapeutic target.