慢性轻度不可预知应激对小鼠肠道菌群结构的影响

Effect of unpredictable chronic mild stress on gut microbiota in mice

目的运用Illumina测序技术,初步研究不可预知慢性应激模型小鼠肠道菌群结构的变化。方法将24只♂C57BL/6小鼠随机分为对照组和模型组,对照组正常喂养;模型组给予慢性轻度不可预见性压力结合孤养,建立抑郁模型。造模5周后,分别进行糖水偏好测试(SPT)、强迫游泳测试(FST)、悬尾测试(TST)、高架十字迷宫测试(EPMT)。采用LC-MS/MS法测定小鼠海马区神经递质变化;采用Illumina高通量测序分析小鼠粪便微生物。结果模型组小鼠TST、FST不动时间增加,EPMT开放臂时间、糖水偏好率降低;海马5-HT、DA、NE明显降低,Glu升高; Chao、Ace、Shannon指数均明显降低,Simpson指数升高, Lachnospiraceae、Prevotellaceae、Peptococcaceae、Clostridiaceae、Corynebacteriaceae微生物群落比例明显降低,而Verrucomicrobiaceae、Alcaligenaceae微生物群落比例升高;PCA图表明,两组微生物群落结构差异性较大。模型组Verrucomicrobiaceae、Alcaligenaceae、Corynebacteriaceae丰度上升; Deferribacteraceae、Clostridiaceae、Bacteroidaceae、Prevotellaceae、Lachnospiraceae丰度下降。结论不可预知慢性应激小鼠肠道菌群结构发生明显改变,多样性、丰度明显下降,表明抑郁和肠道菌群改变密切相关。

Aim To study the effect of unpredictable chronic mild stress(UCMS)on gut microbiota in mice.Methods C57BL/6 mice were randomly divided into control group and model group.The former was fed normally,while the latter was single-housed and given UCMS.After stimulated for five weeks,the mice were subjected to sugar preference test(SPT),forced swimming test(FST),tail suspension test(TST)and elevated plus maze test(EPMT),respectively.The changes of neurotransmitters in hippocampus of mice were determined by LC-MS/MS.Illumina high-throughput sequencing analysis of mouse fecal microorganisms was performed.Results Behavioral tests showed that the immobility time of mice in model group increased significantly compared with that in control group.Meanwhile,model group stayed in the open arm of EPM for a shorter time,and consumed less sugar water.The contents of 5-HT,DA and NE in hippocampus of model group decreased significantly,while that of Glu increased remarkably.The Chao index,Ace index and Shannon index of model group were significantly lower than that of control group,but the Simpson index increased.The proportions of Lachnospiraceae,Prevotellaceae,Peptococcaceae,Clostridiaceae and Corynebaceriaceae microbial communities were reduced significantly,while that of Clostridiaceae and Corynebaceriaceae were boosted significantly in feces of the depressed mice.The PCA map showed a marked difference in the microbial community structure of the two groups.The abundance of Verrucomicrobiaceae,Alcaligenaceae and Corynebacteriaceae in model mice increased,while that of Deferribacteraceae,Clostridiaceae,Bacteroidaceae,Prevotellaceae and Lachnospiraceae decreased.Conclusion UCMS induced depression mice show changed structure,diversity and richness of gut microbiota,indicating a close relationship between depression and gut microbiota.