Polysaccharides, particularly those derived from medicinal plants (such as aloe vera, Astragalus membranaceus, and mushrooms like Ganoderma lucidum), have been studied for their potential to support or treat colitis, especially in experimental models of inflammatory bowel disease (IBD), including ulcerative colitis. The rationale for their use is based on their immunomodulatory, anti-inflammatory, and prebiotic effects. Some studies have demonstrated that plant-derived polysaccharides can reduce inflammatory cytokine levels, improve gut barrier function, and modulate the composition of the gut microbiota in animal models of colitis. For example, research published in peer-reviewed journals has shown that certain polysaccharides can decrease levels of TNF-α, IL-6, and other pro-inflammatory mediators, and increase anti-inflammatory cytokines, leading to an amelioration of colitis symptoms in rodents.

However, most of the evidence to date is preclinical, with limited high-quality human clinical trials. The available human studies are generally small, preliminary, or use polysaccharide-rich herbal preparations rather than isolated polysaccharides. As such, while there is a scientific basis and promising data from animal studies, the overall level of evidence supporting polysaccharides as a treatment for colitis in humans remains limited (rated 2/5). More rigorous, large-scale clinical trials are needed to confirm efficacy and safety in human patients.