Vaginal Microbiota and Cytokine Levels Predict Preterm Delivery in Asian Women

Abstract

Preterm birth (PTB) is the most common cause of neonatal morbidity and mortality worldwide. Approximately half of PTBs is linked with microbial etiologies, including pathologic changes to the vaginal microbiota, which vary according to ethnicity. Globally more than 50% of PTBs occur in Asia, but studies of the vaginal microbiome and its association with pregnancy outcomes in Asian women are lacking. This study aimed to longitudinally analyzed the vaginal microbiome and cytokine environment of 18 Karen and Burman pregnant women who delivered preterm and 36 matched controls delivering at full term. Using 16S ribosomal RNA gene sequencing we identified a predictive vaginal microbiota signature for PTB that was detectable as early as the first trimester of pregnancy, characterized by higher levels of Prevotella buccalis, and lower levels of Lactobacillus crispatus and Finegoldia, accompanied by decreased levels of cytokines including IFNγ, IL-4, and TNFα. Differences in the vaginal microbial diversity and local vaginal immune environment were associated with greater risk of preterm birth. Our findings highlight new opportunities to predict PTB in Asian women in low-resource settings who are at highest risk of adverse outcomes from unexpected PTB, as well as in Burman/Karen ethnic minority groups in high-resource regions.

Large-scale characterisation of the pregnancy vaginal microbiome and sialidase activity in a low-risk Chinese population

“…In previous work, we have observed that the most prevalent vaginal microbiota community compositions in European Caucasian women are those dominated by L. crispatus (50%) followed by L. iners (25%), whereas the inverse has been reported for Asian and Black women ( L. iners , 48% and 50% v L. crispatu s, 26% and 20%, respectively) 6 . Higher frequency of L. iners dominated vaginal microbiota has also been reported in Indian 43 , Karen and Burman 44 , Hispanic and African American pregnant women 9 , 10 , 17 . Our results therefore provide further evidence that ethnic and/or geographical differences are a major source of variation in the underlying structure and composition of the vaginal microbiome during pregnancy.…”

Large-scale characterisation of the pregnancy vaginal microbiome and sialidase activity in a low-risk Chinese population

“…In previous work, we have also observed that the most prevalent vaginal microbiota community compositions in European Caucasian women are those dominated by L. crispatus (50%) followed by L. iners (25%), whereas the inverse was seen for women self identifying as Asian and Black ( L. iners, 48% and 50% v L. crispatu s, 26% and 20%, respectively)(6). Similarly, higher frequency of L. iners dominated vaginal microbiota has been reported in Indian (39), Karen and Burman (40), Hispanic and African American pregnant women (9,10,17). Our results therefore provide further evidence that ethnic and/or geographical differences are a major source of variation in the underlying structure and composition of the vaginal microbiome during pregnancy.…”

Can Lactobacillus spp. Be a Factor Reducing the Risk of Miscarriage?

“…It may be related to genetic and environmental factors, including geographic location, diet, age, BMI, drug exposure, physical activity, and availability of resources such as access to medical care. However, studies show that the presence of L. iners in the vagina of Asian women does not increase the risk of abnormal pregnancy ( Serrano et al 2019 ; Kumar et al 2021 ).…”