Two related research papers report that dietary wheat fiber protects mice from intestinal inflammation. The studies, published in Science Advances and Mucosal Immunology, link changes in wheat processing to a possible rise in inflammatory bowel disease (IBD). In mice, wheat fiber prevented both acute and chronic intestinal inflammation.
The mechanism differs from that of many soluble fibers. Gut bacteria catabolized wheat fiber and released bioactive anti-inflammatory metabolites, notably polyphenols that had been bound to the fiber. This process reprogrammed intestinal immune cells to suppress inflammation. By contrast, wheat fiber did not work primarily by raising short-chain fatty acids. The protective effect depended on the presence of a microbiota capable of breaking down wheat fiber and freeing those polyphenols.
The authors suggest that modern food processing—especially removing bran from wheat-based products—has reduced dietary wheat fiber and may have helped drive the increasing prevalence of IBD. If the mouse results apply to people, choosing whole wheat breads, pastas and whole grain products instead of refined versions, or adding wheat fiber to processed foods, could reduce IBD risk. Many people in developed countries do not eat enough fiber; health groups recommend 25–38 grams per day.
- Lead authors include Andrew T. Gewirtz and Seong-eun G. Kim.
- Institutions involved include Georgia State, University of Toronto, Purdue, Max Planck Institute for Biology, and Research Diets Inc.
- The work was funded by the National Institutes of Health and a Crohn’s and Colitis Foundation fellowship.
Difficult words
- dietary — relating to what people eat
- intestinal — related to the intestine or gut
- inflammation — body reaction causing redness, swelling, pain
- catabolize — to break down complex molecules into simpler onescatabolized
- metabolite — small molecules produced when substances are broken downmetabolites
- polyphenol — plant compounds with antioxidant and biological activitypolyphenols
- microbiota — community of microbes living in one body area
- refined — processed to remove natural parts or nutrients
- bran — outer layer of cereal grains, removed in refining
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- If the mouse results apply to people, how might choosing whole wheat products change your daily diet and IBD risk?
- What challenges might food manufacturers face if they add more wheat fiber to processed foods?
- Why is the presence of a microbiota that can break down wheat fiber important for the protective effect described?
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