Childhood Crohn's disease and the efficacy of enteral diets.

Enteral diets, both elemental and, more recently, polymeric (whole protein), are used as primary therapy in Crohn's disease and can induce disease remission without the concomitant use of immunosuppressive drugs. Controlled trials comparing enteral nutrition with corticosteroid therapy have given mixed results but suggest, at least in children, that they are as effective as corticosteroids in inducing remission. There is no clear consensus as to which dietary therapy is best. Elemental diets do not seem to be superior to polymeric whole protein-based diets, although further work is necessary. The effect of enteral diets does not seem to be related to the site of intestinal inflammation. Enteral nutrition is particularly appropriate in children and adolescents with Crohn's disease, improving nutrition and promoting growth and pubertal development, and avoiding the systemic toxicity of corticosteroid therapy. Most centers will use it as a first line of treatment. Supplementary enteral nutrition after primary therapy and remission induction may be associated with the prolongation of remission and promotion of linear growth. Pathways by which enteral diets may affect mucosal inflammation are discussed. Enteral diets may inhibit intestinal immune responses by reducing the number of cytokine-producing cells. Enteral nutrition may also boost immunosuppressive pathways, which then endogenously suppress ongoing inflammation. Enteral diets may promote epithelial healing and reepithelialization of Crohn's ulcers and may also reduce the bacterial load in the small bowel.