Differential intestinal and oral microbiota features associated with gestational diabetes and maternal inflammation

Maternal microbiota is involved in many metabolic diseases. However, its role in the pathophysiology of gestational diabetes mellitus (GDM) remains unclear. In this case-control study, we performed a 16S rRNA sequencing-based microbial survey to compare the intestinal and oral microflora at third trimester during pregnancy between 30 GDM and 31 normal controls. Sequentially, a correlation-based network analysis was further performed to explore the interactions among microbiota, maternal and infant blood sugar, and inflammatory markers. Our results show that, compared with controls, the GDM cases showed significant differences in β-diversity and increased Gammaproteobacteria and Hemophilus in intestinal microbiota. Furthermore, the GDM cases showed lower α-diversity, increased Selenomonas and Bifidobacterium, and decreased Fusobacteria and Leptotrichia in oral microbiota. The ROC curve showed the area under the curve to be equal to 0.70 and 0.66 when using oral Leptotrichia or gut Hemophilus, respectively, to predict GDM status. In addition, the components and topography of microbial cooccurrence and coexclusion network were quite distinct by GDM status. In summary, intestinal and oral microorganisms in pregnant women are closely related to the status of GDM in the third trimester of pregnancy. The changes of intestinal and oral microbial features may be noninvasive biomarkers for monitoring the health management of GDM pregnancy.