Metabarcoding Analysis of Oral Microbiome during pregnancy

Pregnancy is a dynamic physiological process involving significant hormonal, immune, and metabolic changes to support fetal growth and development. This study investigates the changes in salivary microbiome and biochemical markers from the second to the third trimester of pregnancy. Saliva samples were collected from 45 pregnant women enrolled in the Qatar Birth Cohort study at two time points (second and third trimesters). DNA was extracted and subjected to 16S rRNA gene sequencing using Oxford Nanopore Technology. Microbial diversity and taxonomic analyses were performed, along with correlation analyses between microbial abundance and clinical parameters. Biochemically, significant increases in BMI, pulse rate, HbA1c, LDL, total cholesterol, and triglycerides were observed in the third trimester compared to the second. Microbial diversity analysis revealed significant changes in microbial richness and composition. Taxonomy analysis showed a significant 3-fold increase in Bacteroidota. Also, a significant decline in Selenomonas and a significant increase in Veillonella, specifically Veillonella dispar and Veillonella atypica, as well as an increase in Granulicatella were observed in the third trimester, along with a significant decrease in Streptococcus sanguinis. Correlation analysis during the second trimester revealed positive associations between BMI, cholesterol, LDL, and Selenomonas, and negative correlations with Streptococcus and Gemella. In the third trimester, BMI was negatively correlated with Campylobacter, glucose levels were negatively correlated with Neisseria, and triglyceride levels were negatively correlated with Prevotella. These findings highlight significant biochemical and microbial shifts during pregnancy, underscoring the importance of monitoring oral health and metabolic changes in pregnant women.

妊娠是一类动态的生理过程，伴随显著的激素、免疫与代谢层面变化，以支持胎儿的生长与发育。本研究旨在探究妊娠中期至晚期唾液微生物组与生化标志物的变化。研究从卡塔尔出生队列（Qatar Birth Cohort）的纳入对象中选取45名孕妇，于两个时间点（妊娠中期与晚期）采集其唾液样本。提取样本DNA后，采用牛津纳米孔技术（Oxford Nanopore Technology）进行16S rRNA基因测序（16S rRNA gene sequencing）。随后开展微生物多样性与分类学分析，并针对微生物丰度与临床参数展开相关性分析。生化层面，相较于妊娠中期，妊娠晚期孕妇的体重指数（Body Mass Index, BMI）、脉搏率、糖化血红蛋白（HbA1c）、低密度脂蛋白胆固醇（LDL）、总胆固醇与甘油三酯均显著升高。微生物多样性分析结果显示，微生物丰富度与群落组成均发生显著变化。分类学分析显示，拟杆菌门（Bacteroidota）的相对丰度较妊娠中期显著升高3倍。此外，妊娠晚期可见月形单胞菌属（Selenomonas）丰度显著下降，韦荣球菌属（Veillonella）丰度显著升高，其中缺陷韦荣球菌（Veillonella dispar）与非典型韦荣球菌（Veillonella atypica）的变化尤为明显；颗粒链球菌属（Granulicatella）丰度亦有所升高，而血链球菌（Streptococcus sanguinis）丰度则显著降低。妊娠中期的相关性分析显示，体重指数、胆固醇、低密度脂蛋白胆固醇与月形单胞菌属呈正相关，而与链球菌属（Streptococcus）及孪生球菌属（Gemella）呈负相关。妊娠晚期则可见，体重指数与弯曲杆菌属（Campylobacter）呈负相关，血糖水平与奈瑟菌属（Neisseria）呈负相关，甘油三酯水平与普雷沃菌属（Prevotella）呈负相关。本研究结果揭示了妊娠过程中生化指标与微生物群落的显著变化，强调了监测孕妇口腔健康与代谢状态变化的重要性。