The traditional view that a single microbe is always responsible for causing alterations in human health is no longer valid. It is becoming increasingly clear that the thousands of bacterial species, which normally inhabit different anatomic regions of the human body, are critical to maintaining health. Accordingly, perturbations in this complex bacterial fingerprint may lead to disease. As part of the University of Washington Sexually Transmitted Infection Collaborative Research Center (STI-CRC), in collaboration with Drs. David Fredricks, Jeanne Marrazzo and Anna Wald, we are studying rapid shifts in microbial content within the human vagina. These shifts often correlate with development of bacterial vaginosis (BV), a condition associated with discharge and increased STI risk. Yet, dramatic changes in microbial levels also occur following intercourse and menses, but do not necessarily lead to BV. It is now possible to correlate measures of species diversity, as well as certain individual species with BV versus a healthy vaginal state.
Microbial shifts occur over time periods of hours. It is therefore challenging to understand the mechanistic pathways that lead to BV. We are using detailed study protocols in conjunction with modeling to assess whether key nutrients allow certain species to outcompete with others. We also hope to identify which species are critical for altering and maintaining bacterial composition. Answers to these questions may allow us to develop more strategic approaches towards treating BV.