PNAS：微生物群与早产风险的关联?

摘要 : 美国斯坦福大学 一项研究提出，怀孕早期阶段的微生物群的组成可能为早产风险提供线索。


美国斯坦福大学 一项研究提出，怀孕早期阶段的微生物群的组成可能为早产风险提供线索。早产发生在怀孕37周之前，它折磨着全世界11%的孕妇，而且与人体内外的微生物相对丰富性有非确定性的关系。在一项关于微生物群和早产的纵向案例对照研究中，David Relman及其同事对49名18岁及以上的孕妇怀孕每一周以及产后的阴道、大便、唾液和牙齿/牙龈的微生物群落进行了采样，其中15名孕妇产下了早产婴儿。微生物群组成和多样性在整个怀孕期间大致保持稳定。阴道微生物群分析表明了有5个主要类型的群落，其中4个主要是由一种不同的乳酸杆菌物种组成。第5个类型缺乏乳酸杆菌，但是却富有很多多样的菌种，它以一种取决于剂量的方式与早产有关联。对于某些具有缺乏乳酸杆菌的阴道微生群的女性，加德纳菌和脲原体的丰富程度与早产有关联。不论是顺产还是剖腹产，多数女性表现出了分娩之后微生物群组成朝着多样化微生物群的急剧而持久的变化，其标志是乳酸杆菌水平低以及普雷沃氏菌和嗜胨菌等厌氧菌的出现。这组作者说，怀孕早期阶段的微生物群可能为早产风险提供线索，并且可能影响产后的母亲健康。

原文链接：

Temporal and spatial variation of the human microbiota during pregnancy

原文摘要：

Despite the critical role of the human microbiota in health, our understanding of microbiota compositional dynamics during and after pregnancy is incomplete. We conducted a case-control study of 49 pregnant women, 15 of whom delivered preterm. From 40 of these women, we analyzed bacterial taxonomic composition of 3,767 specimens collected prospectively and weekly during gestation and monthly after delivery from the vagina, distal gut, saliva, and tooth/gum. Linear mixed-effects modeling, medoid-based clustering, and Markov chain modeling were used to analyze community temporal trends, community structure, and vaginal community state transitions. Microbiota community taxonomic composition and diversity remained remarkably stable at all four body sites during pregnancy (P > 0.05 for trends over time). Prevalence of a Lactobacillus-poor vaginal community state type (CST 4) was inversely correlated with gestational age at delivery (P = 0.0039). Risk for preterm birth was more pronounced for subjects with CST 4 accompanied by elevated Gardnerella or Ureaplasma abundances. This finding was validated with a set of 246 vaginal specimens from nine women (four of whom delivered preterm). Most women experienced a postdelivery disturbance in the vaginal community characterized by a decrease in Lactobacillus species and an increase in diverse anaerobes such as Peptoniphilus, Prevotella, and Anaerococcus species. This disturbance was unrelated to gestational age at delivery and persisted for up to 1 y. These findings have important implications for predicting premature labor, a major global health problem, and for understanding the potential impact of a persistent, altered postpartum microbiota on maternal health, including outcomes of pregnancies following short interpregnancy intervals.

doi: 10.1073/PNAS.1502875112

作者：Daniel DiGiulio

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