The dominance of a particular type of bacteria in the cervicovaginal mucus (CVM) apparently increases the likelihood that the mucus will trap HIV, thus theoretically decreasing the chances of acquiring the virus. Publishing their findings in the journal mBio, researchers took CVM specimens from 31 women of reproductive age and studied the samples using high-resolution, time-lapse microscopy to determine whether the mucus trapped HIV-like particles or if they freely diffused.

There were two groups of CVM samples, one that trapped HIV well and another that didn’t. The researchers could not attribute this difference to the pH of the mucus, the total lactic acid present, or the Nugent score, which is an approximate indicator of vaginal health based on the balance of certain bacteria types.

The investigators theorized that the difference was caused by the presence Lactobacillus crispatus bacteria: When that type of bacteria dominated the CVM, the mucus more effectively trapped HIV, thus preventing it from spreading.

The scientists theorize that this finding could lead to new prevention methods for HIV and other sexually transmitted infections.

To read a press release about the study, click here.

To read the study abstract, click here.