A Pilot Study for Establishing DSS-Induced Colitis Model in Minipigs.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by relapsing and remitting colonic mucosal inflammation. Rodent dextran sodium sulfate (DSS) induced colitis models are widely used but have limited translational relevance due to anatomical and physiological differences. As a pilot feasibility study, this work aimed to explore whether graded DSS administration could induce reproducible colitis-like features in minipigs. METHODS: We developed a pilot large-animal UC model using Sus scrofa minipigs. Eight male Micropigs® were divided into four groups, with three groups receiving DSS at 0.2, 0.4, or 0.8 g/kg/day for 7 days. Clinical signs, body weight, colon length, endoscopic evaluation, and histopathology were assessed. RESULTS: DSS administration induced dose-dependent UC features. Group 4 minipigs (0.8 g/kg/day) showed the most severe clinical manifestations, including diarrhea, anorexia, and lethargy. Colon length was reduced by 34% in Group 4 compared to controls. Endoscopy revealed progressive mucosal edema, hemorrhage, and erosions. Histopathological scoring confirmed severe inflammation, crypt loss, and ulceration in higher-dose groups. Dose-dependent trends were consistently observed across clinical signs, endoscopic findings, and histopathological features. CONCLUSION: This DSS-induced minipig colitis model replicates clinical, endoscopic, and histological hallmarks of human UC. As an exploratory pilot study, it provides proof-of-concept for minipigs as a translational platform for inflammatory bowel disease (IBD) research and therapeutic evaluation.