Association of vaginal microbiome, cytokines, and spontaneous preterm birth among Chinese women: a nested case-control studyOriginal 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 nested case-control study asked whether the mid-pregnancy vaginal microbiome and vaginal cytokines predict spontaneous preterm birth (sPTB) in Chinese women. Researchers profiled vaginal swabs using full-length (V1-V9) 16S rRNA PacBio sequencing. They measured 32 bacterial taxa and multiple interleukins in vaginal fluid. Least absolute shrinkage and selection operator (LASSO) regression then selected the strongest predictors. A multivariable logistic regression model was built and tested with fivefold cross-validation.
Who was studied?
The cohort was 190 pregnant Han Chinese women from a hospital in Ningbo, Zhejiang, China. All had singleton pregnancies and were enrolled between 16 and 28 weeks. There were 38 sPTB cases and 152 term controls, selected at a 4:1 ratio. Mean age was about 30 years. The sPTB group had more women over 35 years (28.9% vs 10.5%). Vaginal fluid was sampled once from the posterior fornix.
What were the most important findings?
Women with sPTB had significantly higher relative abundance of Aerococcus, Gardnerella swidsinskii, and Lactobacillus iners than term controls (all p below 0.05). They also had higher vaginal IL-1 beta, IL-6, and IL-12p70. Median IL-6 was 19.29 versus 7.86 pg/mL in term women (p=0.002). Alpha diversity and community state type distribution did not differ significantly. LASSO selected Lactobacillus iners, Gardnerella swidsinskii, and IL-6, with adjusted odds ratios of 1.57, 1.45, and 2.05. The combined model reached an AUC of 0.73.
What are the greatest implications of this study?
The results suggest specific vaginal bacteria and inflammation markers track with preterm risk in Chinese women, a population studied less than European or African cohorts. Combining Lactobacillus iners, Gardnerella swidsinskii, and IL-6 improved discrimination over any single marker. The findings are associations, not proof of cause. Single-center sampling, a single timepoint, and a small case number limit them. The authors urge larger multicenter studies before clinical use.