Ever since the pH of the vagina was found to be much more acidic than blood and interstitial
fluids, a belief going back more than a century has persisted that the vagina is protected
from pathogenic organisms by the high level of hydronium ions present. A corollary of this
belief is that the pH of the vagina and antipathogen activity is due to colonizing Lactobacilli.
Unfortunately, this dogma lacks empirical research support. The vaginal pH is determined by
the interplay between vaginal physiological processes and microbiology. An acidic vaginal …