Importance of the Microbiome in HIV Prevention and HIV Disease (Pt 1)

So you’ve just finished a hot, relaxing shower with your favorite shower gel and then you brush your teeth with your brand new electric toothbrush. You feel sparkling clean as you dress for a date. Well, in reality, you are essentially a walking sewer of bacteria. No matter how clean you may think you are, your body is a seething cauldron of bacteria and other microorganisms. Sound scary? No worries. It’s all good.

It’s estimated that our bodies host anywhere from 10 to 100 trillion bacteria. That’s Trillion with a “T”! Throughout our bodies, a healthy person has communities of bacteria and these species are vitally important to our health because they carry out many important functions. This is especially true for the bacteria in our intestines, but for other areas as well. Specialized communities of bacteria live in our oral cavity, lungs, skin, intestines and reproductive tract. These healthy bacteria are called the normal flora.

We are increasingly beginning to understand that diseases can be linked to changes in the normal flora, when bacteria that aren’t so friendly displace bacteria that are normal flora creating an imbalance. Also, antibiotics used to treat infections from invading bacteria can sometimes damage the normal flora and possibly lead to an imbalance between bacterial species.The variety of bacterial species in an organ, whether they reflect health or disease, are referred to as the microbiome (my-crow-BI-ome).

The risks of acquiring or transmitting HIV are related to the microbiome in the reproductive tract. We will focus on the vaginal microbiome and the risk for HIV infection.

One species of bacteria that is important normal flora in the vagina is called Lactobacillus. Studies have shown that when Lactobacillus is the most common bacteria in the vagina, there is a reduced risk of HIV transmission.There appear to be racial differences in the levels of Lactobicillus in the vagina, where this species is the major bacterial species in white women, but is found at a lower percentage in African, Asian and Hispanic women.