Composition of the vaginal microbiome varies widely among and within individuals over time, but factors underlying the establishment and stability of these communities are not well understood. In an effort to expand our understanding of what constitutes a ‘normal and healthy’ vaginal microbiome, my PhD research is aimed at characterizing dynamics of vaginal microbiota over short and long time scales and investigating how particular bacterial species or strains contribute to differences in function and stability.
Longitudinal dynamics of the vaginal microbiome during puberty
This study assesses longitudinal changes in vaginal microbiomes during puberty at the onset of menarche, when physiologic changes are likely to have profound effects on the microbiome. Our findings indicate the vaginal microbiome of most girls are dominated by lactobacilli early in puberty, typically before the onset of menarche, and are very similar to the types of communities observed in healthy adults. Moreover, many healthy girls harbor bacterial species that have previously been associated with bacterial vaginosis in adults. These findings improve our understanding of the normal development of the vaginal microbiome during puberty and will better inform clinical approaches to gynecologic care of adolescent girls. [paper][GitHub]
Gardnerella vaginalis — friend or foe?
Comparative and evolutionary genomics
Bacterial vaginosis (BV) is a common vaginal disorder typified by itching, odor, discharge and elevated risk to sexually transmitted infections. While its exact etiology is unknown, Gardnerella vaginalis has frequently been singled out as the most likely culprit because of its presence in nearly all BV cases. However, the bacterium is also detected in many healthy individuals, precluding a definitive link between G. vaginalis and BV in the traditional paradigm of Koch’s postulates of disease. Previous studies suggest the species is highly diverse and may comprise several distinct ‘ecotypes’ with variable association to BV. This study delves into the genomic diversity and evolutionary history of G. vaginalis to identify important gene functions that define this enigmatic species.
Metagenomics in healthy girls and women with G. vaginalis
In addition to genomes from public databases, we are comparing genomic sequences of Gardnerella recovered from the vaginas of healthy girls and women to further explore the species in the context of ‘normal and healthy’ conditions. Our subjects include adolescent girls, reproductive-age women, and postmenopausal women. The aim of this study is to investigate whether the G. vaginalis found in these healthy individuals are genetically and functionally distinct from those found in women with symptomatic BV. These investigations will provide a broader foundation for understanding the ecology of G. vaginalis in health and disease.
Project supervisor: Dr. Larry Forney
- Development of a ‘metagenomic’ vaginal microbiome microarray
- Comparative genomics of vaginal Lactobacillus spp. [paper]
- Daily temporal dynamics of vaginal microbiota in relation to bacterial vaginosis [paper]
- Effects of tampons and menses on vaginal microbiota [paper]