The autoimmune disorder celiac disease results in mucosal inflammation and injury of the small intestine, driven by dietary gluten, resulting in a wide range of varied symptoms. Although most patients’ symptoms improve on a gluten-free diet, the restriction can lead to nutrient deficiencies including fiber. Because of that, many people with celiac disease are advised to eat more fiber, either through diet or supplements. Now, new research suggests that the benefits of that fiber may depend on the composition of the microbiome. Although duodenal microbiota has been known to be altered in celiac disease, how the microbial fiber metabolism is affected has remained unknown. The new study found that people with celiac disease had a significantly reduced capacity to metabolize dietary fiber in the small intestine due to the lack of Prevotellaceae bacteria. Because the finding was observed in both newly diagnosed people and in those who have been managing celiac disease for years with a gluten-free diet, this result was determined to be independent of treatment with the gluten free diet. This work is published in the article, “Small intestinal microbial fiber metabolism dysfunction in celiac disease,” published in Nature Communications. “Originally, we thought that the problem was that people aren’t getting enough fiber,” says Mark Wulczynski, PhD, postdoctoral fellow with McMaster’s Farncombe Nutrition Initiative. “Then we found out that people might not have the right bacteria to use the fiber that they’re already eating. Adding more fiber won’t be the solution unless you fix the underlying problems with…
