High amylose polysaccharide, specifically high-amylose maize starch (HAMS), has scientific evidence supporting its use in the management of colitis, particularly in the context of experimental models and early clinical studies. HAMS is a type of resistant starch that is not digested in the small intestine and reaches the colon, where it undergoes fermentation by gut microbiota, resulting in the production of short-chain fatty acids (SCFAs) such as butyrate. Butyrate has well-documented anti-inflammatory properties and is a preferred energy source for colonocytes, promoting mucosal health and repair.

Several animal studies have demonstrated that diets supplemented with high amylose starch can reduce the severity of colitis induced by chemicals such as dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS). These benefits are attributed to increased butyrate production, modulation of immune responses, and support of a beneficial microbiome profile. Early human studies, though limited, suggest that resistant starch supplementation can increase fecal butyrate and may improve symptoms or biomarkers in patients with inflammatory bowel disease (IBD), which includes ulcerative colitis.

However, large-scale, high-quality clinical trials are still lacking, and most evidence comes from preclinical or small pilot studies. Thus, while there is a plausible scientific rationale and preliminary evidence, stronger clinical data are needed to firmly establish efficacy in colitis treatment.