文章：Diversity of vaginal microbiota increases by the time of labor onset 

(https://www.nature.com/articles/s41598-017-17972-0)

研究目的：对于分娩阶段的生殖道微生物未有确切研究Vaginal microbiota is an important early source of bacterial colonization for newborns. However, only a few small studies have investigated the composition of vaginal microbiota during labor.

研究方法：一个256人参加的益生菌喂养计划，采取36周和分娩时期样本，16S rRNA sequencing. In this work, we analyzed vaginal swabs collected at 36 weeks gestation and at the onset of labor from 256 women participating in a randomized placebo-controlled study of probiotic supplementation for the prevention of atopic dermatitis in offspring.

研究结果：

1)菌群结构较为相近

2）时间上的差异会比样本间的差异更小

3) community state type在两个时间点中的变化

4) community state 与bacterial vaginosis, preterm birth, probiotic supplementation均没有关系。

研究结论：

we report that although vaginal microbiota at labor resembled microbiota during pregnancy, bacteria associated with CST IV were significantly overrepresented. We also show that those women who shifted their dominant microbiota by the time of labor onset, tended to shift towards CST IV. CST IV microbiota type was not significantly associated with either self-reported bacterial vaginosis during pregnancy, preterm birth or birthweight of the child. Probiotic consumption did not affect the microbial community profile and administered probiotic strains were not translocated to the vaginal tract.

感想：

1) 菌群在2个时间点的结构差异分析有点少