With so many women wondering if their vaginal discharge is normal, it seemed time to review the basics of “vaginal ecology”. We’ll be examining the following questions:

What is normal? How often does it change? Do hormones make a difference? What about douching or washing? Does my choice of birth control have an impact?

What is “normal” vaginal discharge?

A normal discharge is made up from exfoliated vaginal skin cells, bacteria, and secretions from the cervix and vaginal walls. While as many as 30 types of bacteria can be found in normal vaginal discharge, about 95% of a healthy vaginal bacteria population consists of lactobacilli. There are several subtypes of lactobacilli, but the most important type produces hydrogen peroxide. Just like hydrogen peroxide is used to clean cuts and scrapes on the surface of external skin, the hydrogen peroxide produced by the lactobacilli helps decrease the numbers of undesirable bacteria such as E. coli, a common bowel bacteria responsible for urinary tract infections. A healthy vaginal pH is relatively acidic (pH 3.8-4.5). An acidic pH also discourages undesirable bacteria.

In one study (Mijac, 2006), women with yeast were found to have almost as many of the beneficial, hydrogen peroxide producing lactobacilli as women without infections (77% vs 80% respectively). By contrast, women with trichomoniasis had 63%, and those with bacterial vaginosis (BV) were found to have only 25.6% ! In all categories, women who smoked had fewer of the beneficial lactobacilli than nonsmokers.

Women have tried various home remedies to increase lactobacilli numbers in their vagina. Use of natural yogurt as a douche or on a tampon has been advocated. Yet studies suggest that the type of lactobacilli in yogurt lack both the hydrogen peroxide producing qualities, and an ability to cling to vaginal membranes. In a recent experiment (Larsson, 2008) women treated for BV were given 10 days of freeze dried human lactobacilli, or a placebo, as a vaginal capsule. After three months of this treatment the researchers found that the lactobacilli treatment was most effective in preventing relapse of BV in women who were initially cured using antibiotics.