It’s no secret that your vagina can do some pretty amazing things. But it might be even more awe-inspiring than you think.
According to new research from the University of North Carolina (UNC) at Chapel Hill, the bacteria in your vagina could be protecting you from sexually transmitted diseases, including HIV.
For the study, scientists examined vaginal mucus from 31 women and used high-resolution time-lapse microscopes to test whether HIV particles became trapped in the mucus or spread out (which could then lead to an infection). The results were published in mBio, an open-access journal published by the American Society for Microbiology.
Vaginal bacteria is considered “healthy” if it’s dominated by a species of the bacteria Lactobacillus, lead study author Sam Lai, Ph.D., an assistant professor at the UNC Eshelman School of Pharmacy, said in a press release. But Lai and his team discovered that a strain of this bacteria, Lactobacillus crispatus, helps create a mucus barrier that fights off HIV and other STDs.
Cervicovaginal mucus that contained Lactobacillus crispatus and higher levels of the compound D-lactic acid was very good at trapping HIV, researchers found.
But not all cervicovaginal mucus is created equal. Researchers also discovered that mucus didn’t trap HIV when it had low levels of D-lactic acid, Lactobacillus iners (another type of Lactobacillus) or significant amounts of Gardnerella vaginalis, a bacterium associated with bacterial vaginosis (a condition that happens when you get too much bad bacteria in your vagina).
“These findings could lead to the development of novel strategies to protect women against HIV,” researchers wrote in the study.
The downside: Your body can’t make D-lactic acid, so you can’t take a supplement or eat something new to add it to your cervicovaginal mucus. There’s also no way of knowing the makeup of your vaginal bacteria without undergoing a lab test like this, so you’ll definitely want to keep having safe sex. Still—pretty cool!