目的 前瞻性研究妊娠期糖尿病（gestational diabetes mellitus，GDM）与正常产妇初乳菌群的丰度以及对其多样性进行评估分析。 方法 选取符合纳入标准的30例GDM产妇作为实验组，30例健康产妇作为对照组，分娩方式均为剖宫产。从所有受试者乳汁标本中分离获得DNA，在Illumina MiSeq平台进行16s rRNA基因V3~V4区扩增子高通量测序。 结果 正常组与GDM组之间评估菌群的丰度指数的Ace指数有统计学差异（P=0.039）。2组研究对象的菌群在除Ace指数外的Alpha多样性上无差异，但在Beta多样性，差异有统计学意义（P=0.001）。GDM产妇母乳中厚壁菌门和变形菌门、链球菌科和孪生球菌科、链球菌属和罗斯氏菌属的相对丰度平均值均低于对照组，而放线菌门、葡萄球菌科、葡萄球菌属的相对丰度平均值较对照组水平更高。 结论 GDM产妇与健康产妇初乳菌群的丰度以及多样性均有差异，GDM母乳中厚壁菌门以及变形菌门相对丰度的减少，可能对其子代早期肠道菌群的建立及早期的生长发育产生影响。定量母乳菌群的构成对该人群及其子代有特殊意义。

Objective To prospectively study the abundance and diversity of bacterial flora in the colostrum of postpartum women with gestational diabetes mellitus（GDM） and normal postpartum women. Methods According to the inclusion criteria，we enrolled 30 postpartum women with GDM and 30 healthy postpartum controls，all undergoing a cesarean delivery. Colostrum samples were collected from each subject to isolate DNA for high-throughput sequencing of the 16s rRNA V3-V4 amplicon using the Illumina MiSeq platform. Results The abundance-based coverage estimator for evaluating microbial richness was significantly different between the normal group and the GDM group（P=0.039）. The two groups showed no significant difference in alpha diversity，but differed significantly in beta diversity（P=0.001）. Compared with the control group，the GDM group showed lower mean relative abundance levels of the Firmicutes and Proteobacteria phyla，Streptococcaceae and Gemellaceae families，and Streptococcus and Roseburia genera； and higher mean relative abundance levels of the Actinobacteria phylum，Staphylococcaceae family，and Staphylococcus genus in the milk. Conclusion The abundance and diversity of colostrum microbiota are different between GDM mothers and healthy mothers，and the decreased relative abundance of Firmicutes and Proteobacteria in the breast milk of women with GDM may influence the establishment of gut microbiota and the growth and development of their children in the early stage. Quantifying the composition of breast milk microbiota has special significance for GDM mothers and their offspring.