Background & objectives: The vaginal microbiota undergoes subtle changes during pregnancy and may affect several aspects of pregnancy outcomes. There has been no comprehensive study characterizing the gestational vaginal and gut microbiota and the dynamics of the microbiota with oral probiotics among Indian women. Hence, the study was aimed to explore the microbiota of pregnant women with normal microbiota and bacterial vaginosis (BV) environments and the effect of oral probiotics on the microbiota and the BV status in these women.
Methods: Using high-throughput Illumina-MiSeq sequencing approach, the 16S rRNA gene amplicons were analyzed and the vaginal and gut microbiota of pregnant women with and without BV and pre- and post-probiotics (Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14) intervention for a month was characterized.
Results: The study revealed a compositional difference in the vaginal and gut microbiota between BV and healthy pregnant women. The vaginal microbiota of healthy women was characteristically predominated by Lactobacillus helveticus, followed by L. iners and L. gasseri; in contrast, women positive for BV harboured higher α-diversity and had lower abundance of L. helveticus. Similarly, Prevotella copri, a gut microbe, associated with normal environment was detected in the vaginal samples of all pregnant women without BV, it remained undetected in women with the infection, while all women with BV had Gardnerella vaginalis, which decreased significantly with probiotic treatment. Gut microbiota also revealed dominant abundance of P. copri in healthy women, whereas it was significantly lower in women with BV. The bacterial clade, P. copri abundance increased from 9.17 to 16.49 per cent in the probiotic group and reduced from 7.75 to 4.84 per cent in the placebo group.
Interpretation & conclusions: This study showed gestational vaginal and gut microbiota differences in normal and BV environments. With probiotic treatment, the dynamics of L. helveticus and P. copri hint towards a possible role of probiotics in modulating the vaginal microbiota.

中文翻译：

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细菌性阴道病孕妇的阴道和肠道微生物群多样性和口服益生菌的作用：一项探索性研究

背景和目标：阴道微生物群在怀孕期间会发生微妙的变化，并可能影响怀孕结果的几个方面。在印度女性中，还没有一项全面的研究来描述妊娠期阴道和肠道微生物群以及微生物群与口服益生菌的动态。因此，本研究旨在探索具有正常微生物群和细菌性阴道病（BV）环境的孕妇的微生物群，以及口服益生菌对这些女性微生物群和 BV 状态的影响。
方法:使用高通量 Illumina-MiSeq 测序方法，分析16S rRNA基因扩增子以及患有和未患有 BV 以及益生菌前后的孕妇的阴道和肠道微生物群。鼠李糖乳杆菌GR-1 和罗伊氏乳杆菌RC-14) 干预一个月的特点。
结果：该研究揭示了 BV 和健康孕妇之间阴道和肠道微生物群的组成差异。健康女性的阴道菌群以瑞士乳杆菌为主，其次为L. iners和L. gasseri；相比之下，BV 阳性的女性具有较高的 α 多样性，并且L. helveticus的丰度较低。同样，普氏菌，在所有没有 BV 的孕妇的阴道样本中检测到与正常环境相关的肠道微生物，在感染的女性中仍未检测到，而所有 BV 的女性都有阴道加德纳菌，益生菌治疗显着减少。肠道微生物群还揭示了健康女性中P. copri的主要丰度，而在患有 BV 的女性中则显着降低。益生菌组的细菌进化枝P. copri丰度从 9.17% 增加到 16.49%，而安慰剂组从 7.75% 减少到 4.84%。
解释和结论：这项研究显示了正常和 BV 环境中妊娠期阴道和肠道微生物群的差异。通过益生菌治疗，瑞士乳杆菌和 P. copri 的动态表明益生菌可能在调节阴道微生物群中发挥作用。