Inflammatory bowel diseases (IBD) are impacted by dietary factors, including non-digestible carbohydrates (fibers), which are fermented by colonic microbes. Fibers are overall beneficial but not all fibers are alike and some IBD patients report intolerance to fiber consumption. Given reproducible evidence of reduced fiber-fermenting microbes in IBD patients, we hypothesized that fibers remain intact in select patients with reduced fiber-fermenting microbes and can then bind host cell receptors, subsequently promoting gut inflammation.