Preterm birth remains the main contributor to early childhood mortality. The vaginal environment, including microbiota composition, might contribute to the risk of preterm delivery. Alterations in the vaginal microbial community structure might represent a risk factor for preterm birth. Here, we aimed to (a) investigate the association between preterm birth and the vaginal microbial community and (b) identify microbial biomarkers for risk of preterm birth. Microbial DNA was isolated from vaginal swabs in a cohort of 69 women enrolled at hospital admission for their delivery. Microbiota was analyzed by high-throughput 16S rRNA sequencing. While no differences in microbial diversity measures appeared associated with the spontaneous preterm and full-term outcomes, the microbial composition was distinct for these groups. Differential abundance analysis showed Lactobacillus species to be associated with full-term birth whereas an unknown Prevotella species was more abundant in the spontaneous preterm group. Although we studied a very miscegenated population from Brazil, our findings were similar to evidence pointed by other studies in different countries. The role of Lactobacillus species as a protector in the vaginal microbiome is demonstrated to be also a protector of spontaneous preterm outcome whereas the presence of pathogenic species, such as Prevotella spp., is endorsed as a factor of risk for spontaneous preterm delivery.

中文翻译：

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定义早产风险的微生物生物标志物

早产仍然是幼儿死亡率的主要原因。阴道环境，包括微生物群组成，可能会增加早产的风险。阴道微生物群落结构的改变可能是早产的危险因素。在这里，我们的目的是（a）调查早产与阴道微生物群落之间的关联，以及（b）确定早产风险的微生物生物标志物。从 69 名入院分娩的妇女的阴道拭子中分离出微生物 DNA。通过高通量 16S rRNA 测序分析微生物群。虽然微生物多样性指标与自发性早产和足月结局之间似乎没有差异，但这些群体的微生物组成是不同的。差异丰度分析显示，乳杆菌属物种与足月出生相关，而未知的普氏菌属物种在自发性早产组中更为丰富。尽管我们研究了来自巴西的混血人口，但我们的研究结果与不同国家的其他研究指出的证据相似。乳酸菌在阴道微生物组中作为保护者的作用被证明也是自发性早产结果的保护者，而致病菌（如普雷沃菌属）的存在被认为是自发性早产的风险因素。