The impact of exclusive enteral nutrition on the intestinal microbiota in inflammatory bowel disease.

It is increasingly clear that the intestinal microbiota plays key roles in the pathogenesis of the conditions known as Crohn disease and ulcerative colitis (jointly known as the inflammatory bowel diseases). Perturbations of the microbiota, termed dysbiosis, are present at diagnosis and likely reflect earlier environmental influences along with interactions with intestinal immune responses. Over the last two decades, there has been increasing interest in the use of a nutritional therapy to induce remission of active Crohn disease. Amongst a number of recent studies focusing on the putative mechanisms of action of enteral nutrition in Crohn disease, there have been several reports illustrating profound interactions between this nutritional therapy and the intestinal microbiota. Although at present it is still not clear how these changes relate to concurrent improvements in inflammation, it has become an area of increasing interest. This review article focuses on the impacts of nutritional therapy in individuals with active Crohn disease and overviews the most recent data arising from international studies.