The penile microbiota of Black South African men: relationship with human papillomavirus and HIV infectionOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This cross-sectional study examined the penile skin microbiota of men in relation to human papillomavirus (HPV) and HIV infection. It analyzed archived samples from an HPV Couples Cohort Study in South Africa. Penile swabs of the shaft, foreskin, and glans were profiled by Illumina 16S rRNA gene sequencing of the V3 to V4 regions. Community state types, diversity, and differentially abundant taxa were compared across infection status using machine learning approaches including LEfSe.
Who was studied?
Participants were 238 heterosexually-active Xhosa-speaking Black South African men aged 19 to 67 years, recruited from Gugulethu, Cape Town, South Africa. The median age was 36 years and all circumcised men were traditionally circumcised. Among them, 54.6 percent were positive for any HPV and 37.0 percent for HIV. High-risk HPV was detected in 42.9 percent (102 of 238). This was a human cohort using archived penile specimens with confirmed sample integrity.
What were the most important findings?
Corynebacterium and Prevotella were the most abundant genera, and communities clustered into six community state types. CST-1, dominated by Corynebacterium, had fewer high-risk HPV infections; men there had lower odds of high-risk HPV (odds ratio 0.6, 95 percent CI 0.3 to 0.9, p = 0.036). Men in CST-5, rich in Prevotella, Clostridiales, and Porphyromonas, were more likely to carry HPV or high-risk HPV (p = 0.034 and p = 0.005). Bacterial-vaginosis-associated Prevotella, Peptoniphilus, and Dialister were enriched in high-risk HPV, while HIV-positive men had greater Staphylococcus abundance.
What are the greatest implications of this study?
The study, the largest culture-independent survey of penile skin microbiota, suggests penile bacterial communities differ meaningfully with HPV and HIV status. Corynebacterium dominance tracked with less high-risk HPV, while anaerobic bacterial-vaginosis-associated taxa tracked with more. These associations may reflect increased susceptibility or delayed viral clearance, offering possible microbial targets for HPV and HIV risk. Because the design is cross-sectional, causation cannot be established. Recent sexual exposure and dry-swab sampling are noted limitations, so longitudinal studies are needed.