高摄入红肉通过改变肠道菌群加重小鼠溃疡性结肠炎

观察高摄入红肉对小鼠肠道菌群及溃疡性结肠炎（ulcerative colitis，UC）的影响，并探讨可能的发生机制。

40只Balb/c小鼠随机分为4组：对照组、高红肉组、DSS组和高红肉+DSS组，每组10只小鼠，对照组、DSS组小鼠给予普通饲料，高红肉组、高红肉+DSS组小鼠给予高红肉饲料，均饲养8周；此8周的最后9天开始对DSS组、高红肉+DSS组小鼠给予3% DSS诱导UC。采用实时荧光定量PCR检测小鼠肠道菌群，采用体质量变化、疾病活动指数及HE染色指标评价小鼠UC严重程度，运用Western Blot方法检测小鼠肠道巨噬细胞M1型极化的特征细胞因子。

与对照组相比，高红肉组小鼠肠道厚壁菌门、粪杆菌属及普拉梭菌的丰度显著降低，拟杆菌门、拟杆菌属的丰度显著升高。与DSS组相比，高红肉+DSS组小鼠体质量显著下降，疾病活动指数显著升高，结肠组织病理评分显著升高；与DSS组相比，高红肉+DSS组小鼠TNF-α、IL-1β及IL-6细胞因子表达显著升高。

高摄入红肉导致肠道菌群改变加重小鼠UC。

High red meat intake exacerbates ulcerative colitis in mice by altering gut microbiota

ObjectiveTo observe the influence of high red meat intake on gut microbiota and ulcerative colitis (UC) in mice, and explore the possible mechanisms. MethodsA total of 40 Balb/c mice were randomly divided into 4 groups, namely control group, high red meat group, DSS group, and high red meat+DSS group (n = 10). The control group and DSS group were given ordinary feed, while the high red meat group and high red meat+DSS group were given high red meat diet for 8 weeks; the mice in the DSS group and high red meat+DSS group were given 3% DSS to induce UC in the last 9 days of the 8 weeks. Real-time fluorescence quantitative PCR was used to detect the gut microbiota of mice; weight change, disease activity index and HE staining were used to evaluate the severity of UC, and Western Blot was used to detect the characteristic cytokines of M1-type polarization of mouse colonic macrophages. ResultsCompared with the control group, the abundances of Firmicutes, Faecalibaculum, Faecalibacterium prausnitzii in the high-red meat group decreased significantly, while those of Bacteroidota and Bacteroides increased significantly. Compared with the DSS group, the weight of the mice in the high red meat+DSS group decreased significantly, the disease activity index significantly increased, and the colon histopathological score significantly increased. Compared with the DSS group, the expressions of TNF-α, IL-1β and IL-6 cytokines in the high red meat+DSS group significantly increased. ConclusionHigh red meat intake leads to altered gut microbiota and exacerbates UC in mice.