To investigate the correlation between inflammatory factors in peripheral blood and gut microbiota characteristics and the condition of active ulcerative colitis(UC).

A single center prospective cohort method was used.A total of 171 patients with active UC who were diagnosed and treated in Zhangjiagang Hospital Affiliated to Soochow University from January 2020 to December 2022 were selected as the research objects and as the research group.According to the condition of active UC, they were divided into three subgroups: mild group(79 cases), moderate group(47 cases)and severe group(45 case). Another 100 healthy people who were examined in our hospital at the same time were selected as the control group.Inflammatory factors in peripheral blood were detected by enzyme-linked immunosorbent assay(ELISA), the inflammatory factors in peripheral blood and the characteristics of gut microbiota in each group were compared, and the correlation between the condition of active UC patients and the characteristics of inflammatory factors in the peripheral blood and gut microbiota was analyzed.

The levels of TNF-α, IL-1β, IL-6, IL-17 and the numbers of Escherichia coli and Bacteroides in the research group were significantly higher than those in the control group, while the numbers of Bifidobacteria and Lactobacilli were significantly lower than those in the control group, with statistically significant differences(P<0.05). There was no significant difference in IL-10 level and the number of Enterococcus between the two groups(P>0.05). The results of multivariate logistic analysis suggested that TNF-α, IL-1β, IL-6, IL-17, Escherichia coli, Bifidobacterium, Lactobacillus and Bacteroides were independent factors affecting the condition of patients with active UC(P<0.05). Enterococcus was not an independent factor affecting the condition of patients with active UC(P>0.05). ROC curve results showed that IL-1β, Escherichia coli and Bifidobacteria had a good effect in predicting the condition of patients with active UC, with the area under the curve being 0.869, 0.859 and 0.869 respectively, while IL-6 had a general effect in predicting the condition of patients with active UC, with the area under the curve being 0.715, and TNF-α, Lactobacillus had a lower effect in predicting the condition of patients with active UC(P<0.05).

TNF-α, IL-1β, IL-6, IL-17, Escherichia coli, Bifidobacterium, Lactobacillus and Bacteroides are independent factors affecting the condition of patients with active UC.IL-1β, Escherichia coli and Bifidobacteria have a good value in predicting the condition of patients with active UC.