Florova V, Romero R, Tarca AL, et al. - In view of recent studies suggesting alterations in the vaginal microbiome to be valuable for assessing the risk for spontaneous preterm birth (PTB), the leading cause of neonatal morbidity and mortality worldwide, researchers here examined women who ultimately underwent preterm birth (PTB) and those who delivered at term for the vaginal host immune-microbiome interactions. Between 10 and 32 weeks of gestation, vaginal fluid samples were obtained from 52 pregnant women (of whom 18 underwent PTB and 34 delivered at term) in this case-control study. The assessment of vaginal host immune-microbiome interactions indicated a negative correlation of specific soluble immune mediators, mainly CXCL10, with typical members of Community State Type IV (CST IV) of the vaginal microbiome. Women who ultimately underwent PTB showed stronger negative associations of Sneathia sanguinegens, in particular, with different immune mediators, including CXCL10 and CCL26, compared with those who delivered at term. Findings thus yield information concerning the vaginal host immune-microbiome interactions in normal and complicated pregnancies.