A new study reveals that circumcision may protect men against HIV and other viral infections because the procedure alters the various kinds of bacteria that exist on the penis.
"The change in the communities is really characterized by the loss of anaerobes. It's dramatic. From an ecological perspective, it's like rolling back a rock and seeing the ecosystem change," said Lance Price from the Translational Genomics Research Institute and George Washington University.
"You remove the foreskin and you're increasing the amount of oxygen, decreasing the moisture-we're changing the ecosystem," said Price who was not involved in the study.
Researchers found that the amount of bacteria on the penis dropped a year following a circumcision, changing the bacterial landscape from anaerobic to aerobic.
And this is not the first study to suggest that circumcision presents men with protection against HIV.
Previous studies have demonstrated that men have an estimated 50 percent lower risk of being diagnosed with HIV.
For this study, researchers collected swabs from circumcised men in Uganda and analyzed bacteria communities from each sample. The bacterial composition in both circumcised and uncircumcised men were then compared, as well as the bacterial presence before and after the procedure.
"There was a dramatic and significant change in the penis microbiome as a result of male circumcision," Price said.
The study, published in the journal mBIO, also found that anaerobic bacteria decreased a large amount, changing the microbiome population on the penis.
Researchers are still trying to figure out how the bacterial alteration present via circumcision affects how HIV is contracted.
"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," Price said.
"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."