In reality we have more bacteria, by far, than cells in our body. The behavior of the bacteria in our body is critical to our good health, as well as being critical to curing many diseases. Vaginal health is one example of an organ system that is only healthy if the right balance of bacteria is present. Bacterial Vaginoisis (BV) is an infection gets started when you lose the normal, healthy, vaginal lactobacilli. There are actually many groups of bacteria in the vagina, and we won't be able to cover all of them in a short discussion. Lactobacilli species produce, by metabolizing the sugars in the cells of the vagina and through this metabolism emit a small amount of hydrogen ,which then keeps the vagina very acidic. If the lactobacilli colonies decrease due to being over grown by other species the vaginal pH changes, becomes too basic (less acidic, the pH rises), and other bacteria, that are more hostile to vaginal health will flourish.
There are normally over 100,000 colonies of bacteria growing in the vagina, and those that produce BV are only 1%, a slight increase in that 1% of the vaginal bacterial population can cause discomfort and symptoms of infection. Vaginal itching may be one of the early signs of vaginal infections, and it can occur in women of any age including older women and young girls. BV is not a sexually transmitted disease for the most part, it's just an imbalance of normal bacteria. Exactly the cause of the imbalance is unclear in most cases. Traditionally we have said that too frequent sex, too much douching, antibiotic use, and gyno procedures, probably all contribute to most cases BV most commonly has a thin white or grey discharge, and a distinct odor described as fishy. Both yeast infections and bacterial infections are known to both produce vaginal itching and vaginal discharge.However, there is fascinating new research that has also revealed that some women, genetically, are predisposed to various unique types and levels of bacteria in their vagina. This apparently follows ethnic lines as well as the diet and other things that change what vaginal bacteria we have. Your gyno can help you determine if you are one of these women, and the science is first being studied more in depth.
Vaginal culture has potentially limited role in the confirming of the diagnosis of BV. However, there is no signal bacteria that confirms the diagnosis of BV. Many women can harbor some types of bacteria without symptoms at all and it has been shown that for instance the Gardnerella bactacteria G. vaginalis may be positive most women with symptomatic infection, the Gardneralla organism is also detected in up to 50 to 60 percent of healthy asymptomatic women. Mobiluncus organisms are not in a normal healthy, asymptomatic, woman's vagina. If you test positive for these you may need to be treated for a vaginal infection. It is a personalized approach. Your gyno will need to determine if you also have the physical and other clinical signs of infection. to determine if in fact there is reason to treat any particular culture result that they find. What we don't know is whether women with no symptoms and a positive culture are more likely to become symptomatic if we don't treat, but we think that is probably true.