Nutritional Therapy in Inflammatory Bowel Disease

Chen Sarbagili-Shabat; Rotem Sigall-Boneh; Arie Levine


Curr Opin Gastroenterol. 2015;31(4):303-308. 

In This Article

Insight From Epidemiology and Dietary Changes in Healthy Individuals

Epidemiologic studies have yielded conflicting data regarding the role of carbohydrate exposure as a risk factor.[14] A very large epidemiologic study, the European Prospective Investigation into Cancer and Nutrition (EPIC), prospectively followed 401 326 initially healthy men and women without Crohn's disease or ulcerative colitis from centers in eight European countries. No association was found between carbohydrate intake and onset of ulcerative colitis during the follow-up.[31] Another epidemiologic study, based on yet another analysis of 170 776 women followed during the Nurses Health Study, evaluated the likelihood to develop IBD over 3 317 425 patient-years. They identified 269 incident cases of new-onset Crohn's disease and 338 cases of new-onset ulcerative colitis. Those in the highest quintile for fiber intake were 40% less likely to develop Crohn's disease; fiber from fruit appeared to have the greatest impact on risk reduction.[32]

Investigators from Harvard University and Duke University evaluated the change in microbiota upon exposure to an animal-based diet (meat, eggs and dairy) or a plant-based diet (fruits, vegetables, nuts and legumes) in healthy volunteers. The animal-based diet increased the concentration of fecal bile acids such as deoxycholic acid, increased the abundance bile-tolerant microorganisms such as Bilophila and Bacteroides, and decreased the levels of Firmicutes.[33] Bilophila wadsworthia is a bile-acid-tolerant bacterium that has been linked to colonic inflammation, and was previously found to bloom and aggravate experimental colitis after exposure to milk fat[21] in an IL10−/− knockout mouse model, whereas Firmicutes appear to be sensitive to the changes in fecal bile acids. Another study demonstrated that dietary iron may modify the gut microbiome and increase inflammation in 6-month-old Kenyan infants. Jaeggi et al.[34] performed two double-blind, randomized controlled trials, in which infants consumed low or high iron-fortified maize porridge daily for 4 months. Iron fortification led to a significant increase in enterobacteria and a significant decrease in bifidobacteria. In addition to early-onset dysbiosis, iron fortification increased fecal calprotectin levels, an indicator of intestinal inflammation.