Male Circumcision May Help Protect Against Spread of HIV

First Posted: Apr 16, 2013 09:15 AM EDT

Numerous studies have suggested that male circumcision may aid as a defense against HIV infection. Now, a study led by Lance Price of the Translational Genomics Research Institute suggests that a significant shift in the bacterial community or microbiome of the penis as a result of the procedure may explain how the virus can be protected.

The researchers found that in 156 men from Uganda who were circumcised, the total bacterial load under the foreskin was 33.3 percent less than those who remained uncircumcised one year after the study began. Specifically, it was found that the population of anaerobic bacteria had decreased while the numbers of some aerobic bacteria increased slightly.

Many researchers hypothesize that larger amounts of bacteria in uncircumcised men may activate cells in the foreskin called Langerhans cells, which facilitate the transmission of HIV by recruiting more HIV target cells to the foreskin and delivering the virus to other susceptible cells. However, researchers also note that "curtailing the numbers of bacteria on the penis could prevent these Langerhans cells from betraying the body."

"Understanding the changes in the microbiome following surgery could eventually lead to interventions that don't require a surgical procedure," Price said. "The work that we're doing, by potentially revealing the underlying biological mechanisms, could reveal alternatives to circumcision that would have the same biological impact. In other words, if we find that it's a group of anaerobes that are increasing the risk for HIV, we can find alternative ways to bring down those anaerobes and prevent HIV infection in all sexually active men."

The study is to be published on April 16 in mBio, the online open-access journal of the American Society for Microbiology.

See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone