Abstract: Objective To study the level of inflammatory factors, distribution of intestinal flora, and risk factors in patients with ulcerative colitis, so as to provide scientific basis for the prevention and treatment of ulcerative colitis. Methods Patients with ulcerative colitis who were treated in a hospital in Wenchang City from June 2020 to May 2021 were selected as the case group. The healthy people who underwent physical examination in the hospital （volunteers were recruited according to the age difference of 0.5 years from the case group and the same gender） were selected as the control group. All subjects were investigated by questionnaire survey, intestinal flora detection and inflammatory factor detection. Descriptive analysis method was used to compare the relevant indicators of the two groups, and the univariate and multivariate analysis methods were used to analyze the factors affecting the incidence of ulcerative colitis. Results A total of 200 cases of ulcerative colitis （case group） and 200 healthy persons （control group） were included, with 99 males and 101 females. The average age of the case group was （43.17±8.72） years, and of the control group was （43.54 ±9.11） years. There were no significant differences in the age and gender between the two groups （both P>0.05）. The numbers of Bifidobacterium and Lactobacillus mainly detected in the case group were significantly lower than that in the control group, while Bacteroides, Enterobacter, Enterococcus and Fusobacterium were significantly higher than those in the control group （all P<0.01）. Except for the level of interleukin （IL）-4 in the case group was lower than that in the control group, IL-6, IL-17, IL-23 and tumor necrosis factor （TNF）-α were all higher than those in the control group （all P<0.01）. Alcohol consumption （OR=3.526）, smoking （OR=1.272）, unclean diet （OR=4.592）, co-infection （OR=2.146） and emotional tension （OR=3.919） were all risk factors for ulcerative colitis. Conclusion The species and quantity of intestinal flora in patients with ulcerative colitis are unbalanced, and the level of serum inflammatory factors increases significantly. Good living habits and active health education can reduce the incidence of ulcerative colitis.

Key words: Ulcerative colitis, Inflammatory factor, Intestinal flora, Influencing factor