Lactobacillus spp secretions act both on yeast and epithelial cell surfaces, having perhaps the most significant effect on keeping the microbiota in check. One way they achieve this is by inhibiting the acetylation process through which Candida spp adheres to the vaginal epithelium.⁴ Lactic acid keeps the vagina quite acidic, typically ranging between pH 3.8 and 4.5.⁵

Researchers are still trying to fully understand the various ways in which the complex balance creating healthy homeostasis can go out of kilter, but vaginitis can indicate a vaginal infection. Candidal thrush, bacterial vaginosis (BV), and sexually-transmitted trichomoniasis account for around 90 percent of all vaginitis.⁶

The exact prevalence of these conditions is not known, and the often-quoted statistic that 75 percent of women experience vaginal thrush at some point may be a misrepresentation of a 1977 study. However, there is more agreement that one in three women experience BV at some stage, and this is actually more common than thrush.