Defining microbial biomarkers for risk of preterm labor

Abstract

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