目的 基于肠道菌群GMrepo数据库，在排除性别、年龄、体质量指数（BMI）和国家等影响因素后探讨抑郁组与对照组研究对象的差异菌群，并进一步分层阐明不同年龄和性别抑郁症患者的差异肠道菌群特征。 方法 从GMrepo数据库筛选研究对象，表现型分别为“depression”和“health”，根据纳入标准和排除标准下载筛选后研究对象的相关菌群丰度数据集。通过SPSS 27.0统计软件的病例配对功能，根据性别（1∶1）、年龄（±5岁）、BMI（±1.5 kg·m^-2）和国家（1∶1）匹配对照组及抑郁组研究对象各95例；采用非参数检验对肠道菌群进行单因素分析，筛选假设检验下P<0.05的差异菌群；采用Wald向前逐步选择法二元Logistic回归分析构建模型，根据性别（男性、女性）和年龄（≤65岁、>65岁）进行分层分析，根据比值比（OR）与显著性水平（P值）确定不同层次下对照组人群与抑郁症患者之间有关系有意义的差异菌群。 结果 回归分析，与对照组比较，抑郁组患者普雷沃特菌（Paraprevotella）［OR=0.661， 95%置信区间（CI）=0.489~0.893， P=0.007］和普氏菌（Prevotella）（OR=0.946，95%CI=0.903~0.992，P=0.022）丰度明显偏低，是抑郁症发生的保护因素。男性人群中Paraprevotella（OR=0.358，95%CI=0.146~0.883，P=0.026）为抑郁组与对照组之间的差异性菌群，女性人群中粪杆菌（Faecalibacterium）（OR=0.565，95%CI=0.322~0.990，P=0.046）和另枝菌属（Alistipes）（OR=0.513，95%CI=0.289~0.911，P=0.023）为抑郁组与对照组之间的差异性菌群，年龄≤65岁的人群中Prevotella（OR=0.654，95%CI=0.476~0.899，P=0.009）为差异性菌群。 结论 Paraprevotella、Prevotella、Faecalibacterium和Alistipes为抑郁症的特征性肠道菌群，其丰度改变可能会对抑郁症的发生发展产生重要影响。

Objective To explore the differential flora between depression group and control group Based on the GMrepo database of intestinal flora， after excluding the factors such as gender， age， body mass index（BMI）， and country， and to further clarify the characteristics of differential intestinal flora in the depression patients with different ages and genders. Methods The subjects were selected from the GMrepo database with phenotypes of “depression” and “health”， and the relevant microbial abundance datasets of the screened research subjects were downloaded based on inclusion and exclusion criteria. Using the case matching function of SPSS 27.0 statistical software， 95 control subjects and 95 depression patients were matched into two groups based on gender （1∶1）， age （±5 years）， BMI （±1.5 kg·m^-2）， and country （1∶1）； univariate analysis on intestinal flora using non-parametric tests was conducted to screen the differential intestinal flora with a P<0.05 under hypothesis testing； Wald’s forward stepwise selection method was used to construct a binary Logistic regression model， stratified analysis was conducted based on gender （male， female） and age （≤65 years， >65 years） and the significantly differential flora between the subjects in control group and the patients in depression group were determined based on odds ratio （OR） and P-value within different subpopulatious. Results Compared with control group， Paraprevotella ［OR=0.661，95% confidence interval （CI）=0.489-0.893， P=0.007］ and Prevotella （OR=0.946， 95% CI=0.903-0.992， P=0.022）showed significantly lower abundance in the patients in depression group， which were the protective factors for the occurrence of depression. Paraprevotella（OR=0.358， 95% CI=0.146-0.883， P=0.026） was identified as the differential flora in the male population between depression group and control group， while Faecalibacterium （OR=0.565， 95% CI=0.322-0.990， P=0.046） and Alistipes （OR=0.513， 95% CI=0.289-0.911， P=0.023） were the differential flora in the female population. Prevotella （OR=0.654， 95% CI=0.476-0.899， P=0.009） was the differential flora among the individuals’ age≤65 years between depression group and control group. Conclusion Paraprevotella， Prevotella， Faecalibacterium， and Alistipes are the characteristic intestinal flora associated with depression， and the changes in their abundances may have significant impacts on the occurrence and development of depression.