More and more data continues to confirm the importance of the human microbiota in human health and disease. Much of the work has been focused on the gut microbiota including its influence on behavior as well as local and systemic diseases. In contrast, less is understood about the role of the vaginal microbiome (VM) in human health and disease. Overall, the diversity of the VM appears less than that of the gut. In addition, the compartments (i.e. distal and proximal vaginal vs exocervical vs endocervical) have not been well characterized; mostly because of the close proximity of these sites sample collection has been difficult. The VM consist predominantly of Lactobacillus (L) species. However, defining “healthy” microbiota is challenging since community clustering seems to be a moving target with variability through the women’s menstrual cycle as well her reproductive age. L. iners is present in all women including those with “dysbiosis whereas L. Crisptus is mostly seen in ‘healthy” women. Interestingly the gut does appear to be the reservoir of many of the VM but clearly the vagina is protected from colonization of many of the gut species. Most studies have not revealed much about behavior or environmental influences on the VM which may be due to the fact that most studies are cross-sectional. The few studies examining HPV and the VM have done so in cross-sectional analysis and show a trend toward a relatively low abundance of Lactobacillus spp with increase in anaerobes (such as Prevotella and Leptotrichia). New data has emerged that non-hrHPV is likely a member of the commensal microbiome community and may also have a role in control of hrHPV infections. We have the opportunity to examine the VM over a 20 year span in healthy women from the San Francisco HPV natural history study.
We will present data on VM, immune biomarkers (e.g. cytokine/chemokines) and HPV persistence and clearance as well as examine effects of smoking and contraceptive use; both considered risk factors for cervical cancer development.
The VM is likely critical in controlling hrHPV infections. Environmental influences may include cigarette smoking of which nicotine can be detected from cervical mucous and high estrogen exposure from oral contraceptives.