Isomaltooligosaccharide (IMO) is a prebiotic fiber composed of short chains of glucose molecules. Its use in Inflammatory Bowel Disorders (IBD), such as Crohn's disease and ulcerative colitis, is supported by a modest but growing body of scientific research. Prebiotics like IMO are thought to promote gut health by selectively stimulating the growth and activity of beneficial gut microbiota, which may in turn help modulate immune responses and reduce inflammation—key factors in the pathology of IBD.

Several animal studies have demonstrated that IMO supplementation can improve gut barrier function, reduce inflammatory markers, and shift the gut microbiota towards a more beneficial profile. A few small human studies and pilot trials in patients with IBD or irritable bowel syndrome (IBS) have also shown that IMO may be tolerated and can increase populations of beneficial bacteria such as bifidobacteria. However, direct, large-scale clinical trials on IMO specifically in IBD patients are limited, and results are sometimes mixed regarding its impact on clinical symptoms and disease activity.

Overall, while the theoretical rationale and preclinical data suggest a potential benefit, and IMO is used in some clinical nutrition products for gut health, the direct evidence for IMO as a treatment or supportive therapy for IBD remains preliminary. Thus, the evidence rating is 2 out of 5, reflecting that more robust, targeted clinical research is needed before IMO can be considered a validated therapy for IBD.