A Novel Porcine Model of Ulcerative Colitis: Dose-Dependent DSS-Induced Inflammation and Real-Time Endoscopic Evaluation in Minipigs

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) characterized by recurring inflammation predominantly affecting the colonic mucosa. While rodent models, such as dextran sodium sulfate (DSS)-induced colitis, are commonly utilized for studying UC, their limited anatomical and physiological similarities to humans constrain translational potential. This study aimed to develop a novel, translationally relevant porcine model of UC using Sus scrofa minipigs (Micropigs®). Eight minipigs were allocated into four groups, with three receiving graded doses of DSS (0.2, 0.4, and 0.8 g/kg/day) orally for seven consecutive days, while the control group received no DSS. Clinical signs, body weights, colon lengths, endoscopic evaluations, and histopathological assessments were conducted. Minipigs exhibited dose-dependent clinical manifestations including diarrhea, anorexia, lethargy, and weight loss. Colon shortening correlated significantly with DSS dose severity. High-resolution endoscopic evaluations allowed real-time monitoring and revealed dose-dependent mucosal changes ranging from mild edema to severe erosions and haemorrhage. Histopathological analyses confirmed these findings, demonstrating substantial crypt damage, inflammation, edema, and ulceration in high-dose groups. This minipig model successfully replicates key clinical, endoscopic, and histopathological features of human UC, supporting its utility for advancing preclinical research into pathogenesis, therapeutic intervention, and diagnostic innovation.