Public health school researchers have discovered that some penile bacteria can increase the chances of an HIV infection in men, a risk factor that has previously gone unrecognized.

The study, released Tuesday examined a collection of bacteria under the foreskin of men and found that men who had a large amount of microbes were at greater risk of becoming HIV positive, according to a release from the Milken Institute School of Public Health.

Funded by the National Institutes of Health, the Bill and Melinda Gates Foundation and the Canadian Institutes of Health Research, the study was conducted over a two year period on uncircumcised heterosexual men in Rakai,Uganda, according to the release.

The researchers concluded that a higher number of penile anaerobes, bacteria that can live without oxygen, correlated to a higher production of the biochemicals that are capable of drawing HIV cells to the penis.

The study also found that the penile bacteria risk factor may be sexually transmissible.

Cindy Liu, an assistant research professor of environmental and occupational health, and Lance Price, a professor of environmental and occupational health, co-authored the study.

The study is part of the University’s greater involvement in studying the HIV/AIDS epidemic. Last year, GW researchers received a $28 million NIH grant to study immunotherapy advancements in HIV treatment.