Circumcision has often been the cause of numerous debates, with some reports of the effects of unconventional practices even becoming substantial legal controversies. However, it has also been a perspective to consider when researching the spread of HIV among men. What most studies appear to have found is that circumcision is related to a lower risk of getting HIV by up to 60%. Now a recent study has confirmed this and explained the underlying mechanisms for why this may be.
The study, which was published in mBio, was a prospective observational intervention study. In total, 156 uncircumcised men took part. After the researchers obtained baseline levels of bacteria in the genital area from all of the men, they were randomly split into two groups. In one of the groups all the men received circumcision, whereas the other group did not receive any intervention. Both groups were then followed up a year later, with the same measurements being taken to see the levels of bacteria in the genital area. These results were then compared to the initial baseline levels as well as between groups. The key findings indicated that the circumcised men had a non-significant increase in aerobic bacteria levels and an average of 81% decrease of anaerobic bacteria levels. Based on this the researchers concluded that circumcision positively affected the men’s penile ecosystem as a result of increased oxygen reaching previously covered skin. As a result, the prevalence of anaerobic bacteria levels decrease, which reduces the risk of inflammation that has been associated with making HIV infections more likely.
Several aspects of this study are commendable, with its prospective design perhaps also being its strongest point. Theoretically speaking the findings are useful to rule out other competing theories within this field. Although the findings certainly appear robust, it is also important to bear in mind that understanding underlying mechanisms within biological research requires in depth research to rule out variables and competing theories. As such, the most ideal scenario would be if these findings were replicated in another study. However, it is questionable whether this is feasible given that the execution of this type of research may be rather difficult. Nevertheless, if further studies were to gain an understanding of the underlying mechanisms for this phenomenon, then it would have a substantial impact on developing interventions.
We were not surprised to read about these findings as we are already well aware of other studies where male circumcision was associated with a lower incidence of HSV-2 lower risk of transmission of STIs (such as HPV and Trichomonas Vaginalis infections) to their female partners. Therefore, it should not come as a surprise if we write other significant studies within this field in the future.