重症肺炎患者肠道菌群特征及其与肠道屏障和免疫细胞的相关性

Characteristics of gut flora in patients with severe pneumonia and its correlation with intestinal barrier and immune cell

目的探讨重症肺炎患者肠道菌群特征及其与肠道屏障和免疫细胞的相关性,为该类患者的治疗提供参考。方法选择2021年3月至2022年3月在我院治疗的39例重症肺炎患者为研究组,选择同期我院体检中心40例健康体检者作为对照组,分别收集两组对象粪便样本及血液样本(研究组患者标本留取时间为使用抗生素之前),分析两组对象肠道菌群特征并对肠道屏障及免疫细胞相关指标进行检测,分析肠道菌群特征与上述指标之间的相关性。结果研究组患者二胺氧化酶(DAO)、D-乳酸和内毒素水平均高于对照组(均P<0.05)。研究组患者CD4^(+)T及CD8^(+)T细胞水平均低于对照组,而CD4^(+)T/CD8^(+)T高于对照组(均P<0.05)。研究组患者肠道菌群Chao1指数、Ace指数和Shannon指数均低于对照组,而Simpson指数高于对照组(均P<0.05)。对照组患者肠道双歧杆菌属、瘤胃球菌属、假丁酸弧菌属、粪球菌属、毛螺菌属、普氏菌属为优势菌;而研究组对象肠道埃希菌属、肠球菌属、梭杆菌属、葡萄球菌属、粪芽胞菌属为优势菌群。患者肠道双歧杆菌属、瘤胃球菌属、假丁酸弧菌属、粪球菌属、毛螺菌属、普氏菌属与DAO、D-乳酸、内毒素和CD4^(+)T/CD8^(+)T水平呈正相关,与CD4^(+)T和CD8^(+)T细胞水平呈负相关(均P<0.05)。患者肠道埃希菌属、肠球菌属、致病菌梭杆菌属、葡萄球菌属、粪芽胞菌属与CD4^(+)T和CD8^(+)T细胞水平呈正相关,与DAO、D-乳酸、内毒素和CD4^(+)T/CD8^(+)T水平呈负相关(均P<0.05)。结论重症肺炎患者肠道菌群与肠道屏障功能和免疫细胞水平具有显著相关性。

Objective To investigate the characteristics of intestinal flora in patients with severe pneumonia and its correlation with intestinal barrier and immune cells,so as to provide a reference for the treatment.Methods A total of 39 patients with severe pneumonia treated in our hospital from March 2021 to March 2022 were selected as the observation group.40 healthy individuals identified by the physical examination center of our hospital were included as the control group.Stool samples and blood samples were collected separately(the time for sample collection in the observation group was before the use of antibiotics).The characteristics of intestinal flora in the two groups were analyzed,and the related indicators of intestinal barrier and immune cell were detected.The correlation between intestinal flora and the above two groups of indicators were analyzed.Results The levels of DAO,D-lactic acid and bacterial endotoxin in the observation group were higher than those in the control group(all P<0.05).The levels of CD4^(+)T and CD8^(+)T cells in the observation group were lower,while that of CD4^(+)T/CD8^(+)T was higher than in the control group,respectively(all P<0.05).The intestinal flora Chao1 index,Ace index and Shannon index in the observation group were lower,while the Simpson index was higher than in the control group,respectively(all P<0.05).The dominant flora in the control group were Bifidobacterium,Ruminococcus,Pseudobutyrivibrio,Coprococcus,Lachnobacterium,and Prevotella.The dominant flora in the observation group were Escherichia,Enterococcus,Fusobacterium,Staphylococcus and Coprobacillus.Bifidobacterium,Ruminococcus,Pseudobutyrivibrio,Coprococcus,Lachnobacterium and Prevotella were positively correlated with DAO,D-lactic acid,bacterial endotoxin and CD4^(+)T/CD8^(+)T,and negatively correlated with CD4^(+)T and CD8^(+)T(all P<0.05);Escherichia,Enterococcus,Fusobacterium,Staphylococcus and Coprobacillus were positively correlated with CD4^(+)T and CD8^(+)T cells,and negatively correlated with DAO,D-lactic acid,bacterial endotoxin and CD4^(+)T/CD8^(+)T(all P<0.05).Conclusion The intestinal flora in patients with severe pneumonia are related to intestinal barrier function and immune factor.