A woman's vaginal pH has many implications on her health and it can be a useful tool in disease diagnosis and prevention. For that reason, the further examination of the relationship between the human vaginal pH and microbiota is imperative. In the past several decades, much has been learned about the physiological mechanisms modulating the vaginal pH, and exogenous/genetic factors that may influence it. A unified, coherent understanding of these concepts is presented to comprehend their interrelationships and their cumulative effect on a woman's health. In this review, we explore research on vaginal pH and microbiota throughout a woman's life, vaginal intermediate cell anaerobic metabolism and net proton secretion by the vaginal epithelial, and the way these factors interact to acidify the vaginal pH. This review provides foundational information about what a microbiota is and its relationship with human physiology and vaginal pH. We then evaluate the influence of physiological mechanisms, demographic factors, and propose ideas for the mechanisms behind their action on the vaginal pH.
Keywords: estrogen; lactobacilli; microbiota; pH; vagina.