Comparative analysis of strain-specific gut microbiota dynamics and disease progression in DSS-induced murine colitis

다국어 초록 (Multilingual Abstract)

This study systematically compared the clinical features, pathological lesions, and gut microbiota alterations in BALB/c, ICR, and C57BL/6 mice subjected to dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD). Colitis was induced by administering DSS (5% in BALB/c and ICR; 3% in C57BL/6) for 7 days, followed by 7 days of distilled water. We assessed body weight, clinical signs, colon length, hematological parameters, myeloperoxidase (MPO) activity, histopathology, and gut microbiota profiles via 16S rRNA sequencing. DSS treatment consistently caused weight loss, colon shortening, leukocytosis, and elevated MPO activity. Lesion severity followed the order: C57BL/6>ICR>BALB/c. Histopathology revealed mucosal shedding and immune cell infiltration in all strains. BALB/c mice recovered rapidly after DSS withdrawal, whereas C57BL/6 and ICR mice showed persistent lesions with mortality in the chronic phase. Microbiota analysis revealed strainspecific patterns: BALB/c and ICR largely restored baseline Bacteroidetes–Firmicutes ratios, while C57BL/6 developed sustained dysbiosis with reduced Bacteroidetes and marked expansion of Proteobacteria, particularly Enterobacteriaceae (up to 47.14%). These findings indicate C57BL/6 mice represent a suitable strain for chronic colitis research due to persistent dysbiosis, whereas BALB/c and ICR mice tend to reestablish baseline microbial states. ICR mice, showing comparable responses to inbred strains, also provide a cost-effective option for acute colitis studies. This study establishes a strain-based framework for optimizing DSS-induced IBD model selection.