What is the role of diet in inflammatory bowel disease?

Diet is suspected to play a key role in IBD natural history. IBD patients often believe that diet is associated with symptoms and flares, leading to restrictive diets avoiding dietary components considered as potentially harmful. The risk factors of this restrictive eating disorder are now reported and result from disease activity, from patients' psychological health and from confusing dietary advice. These restrictive diets are at risk of undernutrition, nutritional deficiencies and of mixed anxiety-depressive disorders. Epidemiological studies have highlighted the role of dietary factors in IBD risk. Mediterranean diets tend to reduce the risk of developing IBD. Conversely, the "Western" diet (high intakes of fat, sugar, salt, animal protein and ultra-processed foods) increases the risk of developing IBD. Experimental studies demonstrate the ability of nutrients to modulate the intestinal inflammatory response by influencing the composition of the intestinal microbiota, the function of the intestinal barrier or various actors of immunity. The level of scientific evidence is currently insufficient to propose an anti-inflammatory diet for IBD patients. Nevertheless, promising avenues of clinical research deserve to be investigated in the future through randomised interventional studies. As recommended by ESPEN statements with a strong consensus, every patient should benefit from dietary follow-up by a health professional as part of a multidisciplinary approach.(c) 2023 Publi-shed by Elsevier Masson SAS on behalf of Socie ' te ' francophone nutrition clinique et me ' tabolisme (SFNCM).