Fettweis, J. M. | Search bioRxiv

bioRxiv2021

The Vaginal Microbiome in Women of Reproductive Age with Healthy Weight versus Overweight/Obesity

ObjectiveEvaluate differences between the vaginal microbiome of reproductive-aged women with overweight and obesity (Ow/Ob) compared with healthy weight (HW). MethodsA cohort of 367 non-pregnant women (18-40 years) with Ow/Ob (body mass index [BMI] [≥]25 kg/m2) was case-matched with 367 women with HW (BMI 18.0-24.9 kg/m2). The study was a secondary analysis of 16S rRNA vaginal microbiome surveys through the Vaginal Human Microbiome Study (VaHMP). Groups were matched on age, race/ethnicity, income, and nulliparity status. ResultsMean age and BMI of Ow/Ob and HW groups were 26.8 versus 26.7 years and 37.0 versus 22.1 kg/m2, respectively. The overall vaginal microbiome composition differed between groups (PERMANOVA, p=0.035). Women with Ow/Ob had higher alpha-diversity compared with women with HW (Wilcoxon test, Shannon index p=0.025; Inverse Simpson index p=0.026). Lactobacillus dominance ([≥]30% proportional abundance) was observed in a greater proportion of women with HW (48.7%) compared with Ow/Ob (40.1%; p=0.026). ConclusionsThe vaginal microbiome differs in reproductive-aged women with Ow/Ob compared with women with HW, with increased alpha-diversity and decreased predominance of Lactobacillus. Observed differences in vaginal microbiome may partially explain differences in preterm birth and bacterial vaginosis risk between these populations.

microbiology↗

bioRxiv2020

Unique roles of vaginal Megasphaera phylotypes in reproductive health

The composition of the human vaginal microbiome has been extensively studied and is known to influence reproductive health. However, the functional roles of individual taxa and their contributions to negative health outcomes have yet to be well characterized. Here, we examine two vaginal bacterial taxa grouped within the genus Megasphaera that have been previously associated with bacterial vaginosis (BV) and pregnancy complications. Phylogenetic analyses support the classification of these taxa as two distinct species. These two phylotypes, Megasphaera phylotype 1 (MP1) and Megasphaera phylotype 2 (MP2), differ in genomic structure and metabolic potential, suggestive of differential roles within the vaginal environment. Further, these vaginal taxa show evidence of genome reduction and changes in DNA base composition, which may be common features of host dependence and/or adaptation to the vaginal environment. In a cohort of 3,870 women, we observed that MP1 has a stronger positive association with bacterial vaginosis whereas MP2 was positively associated with trichomoniasis. MP1, in contrast to MP2 and other common BV-associated organisms, was not significantly excluded in pregnancy. In a cohort of 52 pregnant women, MP1 was both present and transcriptionally active in 75.4% of vaginal samples. Conversely, MP2 was largely absent in the pregnant cohort. This study provides insight into the evolutionary history, genomic potential and predicted functional role of two clinically relevant vaginal microbial taxa.

microbiology↗