Changes in serum inflammatory cytokine levels and intestinal flora in a self-healing dextran sodium sulfate-induced ulcerative colitis murine model

Aims: Whether dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) animal models undergo self-healing remains unclear. Therefore, the study aim was to determine if these models have self-healing ability. Main methods: UC was induced using 4% DSS in male KM mice. Histopathological and inflammatory cytokine were evaluated. Fecal samples were analyzed by 16S rDNA gene sequencing. Key findings: Physiological and inflammatory cytokine changed obviously on days 4-14 of establishment and returned to normal levels by day 21. The degrees of inflammation and injury in pathological sections decreased within 14 days compared with those on day 7. Interleukin (IL)-17A, IL-6, and C-reactive protein (CRP) levels fluctuated daily and were highest at 10 AM, 11 AM, and 8 PM, respectively. Intestinal flora disturbance was most obvious on days 7 and 14. The abundances of Lactobacillus and Alistipes decreased, whereas those of Streptococcus, Escherichia-Shigella, and Oscillibacter increased and mostly recovered by day 21. Lactobacillus and serum CRP level were negatively correlated with inflammation, whereas Streptococcus and Escherichia-Shigella were positively correlated with serum IL-6 level. Significance: The DSS-induced UC murine model was shown to undergo self-healing. Intestinal flora disturbance in the model were obvious from days 4 to 14 and had mostly recovered by day 21.