Over the last few years there have been a number of studies suggesting that male circumcision may protect against HIV infection. Several possible reasons have been offered by experts as to why circumcision offers protection against HIV infection. Now here's one more reason...
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 circumcision could explain HIV protection.
The researchers found that in men 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.
The researchers hypothesize that in uncircumcised men, high bacterial loads may activate cells in the foreskin called Langerhans cells, which facilitate the transmission of HIV by recruiting more HIV target cells - namely the CD4+ T-cells, to the foreskin and by delivering the virus to susceptible T-cells. In sharp contrast, curtailing the numbers of bacteria on the penis could prevent these Langerhans cells from betraying the body, say the researchers.
The findings were based on a large circumcision trial in Uganda, which involved 156 men.
Commenting on the study, Price said, "Understanding the changes in the microbiome following surgery could eventually lead to interventions that don't require a surgical procedure. 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.
by RTT Staff Writer
For comments and feedback: firstname.lastname@example.org