目的：通过检测系统性红斑狼疮（systemic lupus erythematosus，SLE）患者肠道菌群丰度变化及外周血淋巴细胞亚群数量，分析关键差异菌群分布与淋巴细胞亚群之间的相关性。方法：共纳入SLE患者23例和相匹配的健康对照（healthy control，HC）16名，流式细胞术检测外周血淋巴细胞亚群数量，16S rRNA技术检测肠道菌群多样性及丰度，分析外周血淋巴细胞亚群数量与肠道菌群的相关性，通过SPSS 26.0进行统计学分析。结果：与HC组相比，SLE组调节性T（regulatory T，Treg）细胞（t=-2.284，P=0.022）、初始CD4⁺T细胞（t=-2.084，P=0.037）、分泌干扰素（interferon，IFN）γ的γδT细胞（t=-2.370，P=0.017）明显减少；SLE组厚壁菌门相对丰度下降（t=-2.323，P=0.020），与Tfr细胞（r=0.544，P=0.029）、生发中心（germinal center，GC）-B细胞（r=0.518，P=0.040）呈正相关；拟杆菌门丰度与Tfr细胞呈负相关（r=-0.521，P=0.039）。结论：SLE患者外周血多种淋巴细胞亚型、肠道菌群结构与HC相比存在显著差异；肠道菌群与淋巴细胞亚群间存在相关性，尤其厚壁菌门、拟杆菌门与Tfr、Tfh、GC-B细胞存在相关性。

Objective To investigate the correlation between the distribution of critical differential bacterial populations and lymphocyte subsets in systemic lupus erythematosus （SLE） patients by detecting the abundance changes of intestinal microbiota and lymphocyte subsets. Methods Twenty-three SLE patients and 16 healthy controls (HC) were included. Flow cytometry was used to detect the number of peripheral blood lymphocyte subsets, and 16S rRNA technology was used to detect the diversity and abundance of intestinal microbiota. The correlation between peripheral blood lymphocyte subsets and intestinal microbiota was investigated, and the experimental data were analyzed using SPSS 26.0. Results Compared with HC, the numbers of regulatory T（Treg） cells, initial CD4⁺T cells, and interferon（IFN）γ-secreting γδT cells in SLE patients were significantly reduced (t=-2.284, P=0.022; t=-2.084, P=0.037; t=-2.370, P=0.017), and follicular regulatory T （Tfr）, follicular helper T （Tfh）, germinal center B （GC-B）and B lymphocytes showed a downward trend. The relative abundance of Firmicutes in SLE patients was significantly decreased (t=-2.323, P=0.020) and was positively correlated with Tfr (r=0.544, P=0.029) and GC-B cells (r=0.518, P=0.040). The abundance of Bacteroidetes was positively correlated with Tfr cells (r=0.521, P=0.039). Conclusions The peripheral blood lymphocyte subsets and intestinal microbiota levels of SLE patients are significantly different from those of HC, there was a correlation between the intestinal flora and lymphocyte subpopulations in the intestinal tract of SLE patients, especially the Firmicutes and Bacteroidetes are positively correlated with Tfr, Tfh and GC-B cells, suggesting that the structural changes of intestinal microbiota may affect lymphocyte subsets and mediate the progression of the disease.