Defining microbial biomarkers for risk of preterm laborOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study asked whether the vaginal microbial community differs between term and spontaneous preterm labor, and sought microbial biomarkers of preterm risk. Vaginal swabs were collected up to four hours before labor began. Microbiota was profiled by high-throughput 16S rRNA sequencing of the V4 region on the Ion PGM platform. Differential abundance was tested with DESeq2, comparing term versus preterm and non-spontaneous preterm versus preterm. Diversity was assessed with Shannon and inverse Simpson indices.
Who was studied?
The cohort was 69 pregnant women admitted for delivery at Hospital de Clinicas de Porto Alegre, Brazil, between 2014 and 2016. Twenty-three had spontaneous preterm labor before 33 weeks and 29 had spontaneous term labor. Seventeen women with medically indicated cesarean before 33 weeks served as a second, non-spontaneous preterm control. The authors highlight the high genetic admixture of the Brazilian population. This was a human observational cohort study.
What were the most important findings?
Two Lactobacillus species were significantly more abundant in women who delivered at term. An unknown Prevotella species was more abundant in the spontaneous preterm group. The preterm group showed a low mean of Lactobacillus reads alongside a tendency toward higher Prevotella. Microbial diversity did not differ across the three groups by Shannon or inverse Simpson indices. Antibiotic use during labor explained about 3.4% of community variation (p = 0.043) and those affected taxa were removed before analysis. Lactobacillus and Prevotella were not strongly correlated (coefficient -0.17).
What are the greatest implications of this study?
The results support Lactobacillus as protective and Prevotella as a candidate risk biomarker for spontaneous preterm labor. The authors call this the first such analysis in a Brazilian cohort. Because vaginal communities vary by ethnic background, findings from an admixed population add generalizability. These are associations from a small cohort, not causal proof. Lactobacillus lowers vaginal pH and inhibits pathogens, while Prevotella can drive inflammation. Larger studies are needed to confirm Prevotella as a predictive marker.