The pH of the vagina is quite acidic, averaging around 4.5 on the pH scale (7 is neutral). That's about as acidic as beer or tomatoes. Busy microbe communities in the vagina maintain this acidity. For example, lactobacillus, a group of lactic acid-producing bacteria, dominates the ecosystem in many women's vaginas. These beneficial bacteria and their acidic output likely keep nasty bugs from moving in and colonizing the place. |