According to a study to be published on April 16 in mBio, the online open-access journal of the American Society for Microbiology, circumcision drastically alters the microbiome of the penis, changes that could explain why circumcision offers protection against HIV and other viral infections.
Research team studied the effects of adult male circumcision on the types of bacteria that live under the foreskin before and after circumcision. By one year post-procedure, the total bacterial load in that area had dropped significantly and the prevalence of anaerobic bacteria, which thrive in locations with limited oxygen, declined while the numbers of some aerobic bacteria increased slightly.
Researchers concluded the change in the communities is really characterized by the loss of anaerobes. From an ecological perspective, it’s like rolling back a rock and seeing the ecosystem change. The foreskin removal increases the amount of oxygen, decreasing the moisture – changes the ecosystem.