Defining microbial biomarkers for risk of preterm labor

Abstract

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.

The vaginal microbiome and the risk of preterm birth: a systematic review and network meta-analysis

“…The most common exclusion criteria of otherwise eligible studies were the lack of CST grouping of results (Supplementary Table S3 ). In the final selection of studies, seven were excluded because a lack of CST grouping 11 , 21 – 26 , all women receiving cervical cerclage 27 , sampling after signs of labor 28 , no information regarding preterm birth for current pregnancy 29 , only the use of polymerase chain reaction (PCR) instead of sequencing 30 or multiple CSTs assigned to each woman because of multiple sampling points 31 .…”

Sequenciamento NGS: Status e Perspectivas

“…Também ajuda nisso o fato de o NGS ser completamente independente do cultivo, permitindo a identificação de microrganismos não cultiváveis, que representam mais de 90% da diversidade microbiana conhecida [23]. O conhecimento hoje já relaciona a microbiota com doenças e comorbidades humanas como Alzheimer [24], parto prematuro [25,26] e autismo [27], tratando o ser humano não mais como um organismo, mas como um "superorganismo" composto de células humanas e microbianas [28]. O mesmo também é válido para relações dos microrganismos com plantas [29] e com animais [30].…”

Ureaplasma and Prevotella Colonization with Lactobacillus Abundance During Pregnancy Facilitates Term Birth

“…In addition, the effect of the microbiome of pregnant women on the prognosis during pregnancy and PTB has been studied. [17][18][19][20][21] However, according to previous studies, the vaginal microbiome shows differences according to race and place of residence 16,22 , and a study has also reported that there is no relationship between PTB and a speci c microbiome in some races. 23 Ureaplasma spp., which is known to be associated with PTB, colonizes the vagina in women without any pregnancy complications.…”