title: The effects of circumcision on the penis microbiome.
abstract: BACKGROUND
  Circumcision is associated with significant reductions in HIV, HSV-2 and HPV infections among men and significant reductions in bacterial vaginosis among their female partners.
  
  
  RESULTS
  We assessed the penile (coronal sulci) microbiota in 12 HIV-negative Ugandan men before and after circumcision. Microbiota were characterized using sequence-tagged 16S rRNA gene pyrosequencing targeting the V3-V4 hypervariable regions. Taxonomic classification was performed using the RDP Naïve Bayesian Classifier. Among the 42 unique bacterial families identified, Pseudomonadaceae and Oxalobactericeae were the most abundant irrespective of circumcision status. Circumcision was associated with a significant change in the overall microbiota (PerMANOVA p = 0.007) and with a significant decrease in putative anaerobic bacterial families (Wilcoxon Signed-Rank test p = 0.014). Specifically, two families-Clostridiales Family XI (p = 0.006) and Prevotellaceae (p = 0.006)-were uniquely abundant before circumcision. Within these families we identified a number of anaerobic genera previously associated with bacterial vaginosis including: Anaerococcus spp., Finegoldia spp., Peptoniphilus spp., and Prevotella spp.
  
  
  CONCLUSIONS
  The anoxic microenvironment of the subpreputial space may support pro-inflammatory anaerobes that can activate Langerhans cells to present HIV to CD4 cells in draining lymph nodes. Thus, the reduction in putative anaerobic bacteria after circumcision may play a role in protection from HIV and other sexually transmitted diseases.
authors.affiliation: Translational Genomics Research Institute (TGen), Flagstaff, Arizona, United States of America. lprice@tgen.org
authors.forename: Lance B
authors.initials: LB
authors.lastname: Price
authors.forename: Cindy M
authors.initials: CM
authors.lastname: Liu
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Johnson
authors.forename: Maliha
authors.initials: M
authors.lastname: Aziz
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Lau
authors.forename: Jolene
authors.initials: J
authors.lastname: Bowers
authors.forename: Jacques
authors.initials: J
authors.lastname: Ravel
authors.forename: Paul S
authors.initials: PS
authors.lastname: Keim
authors.forename: David
authors.initials: D
authors.lastname: Serwadda
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Wawer
authors.forename: Ronald H
authors.initials: RH
authors.lastname: Gray
mesh_terms: D001421:Bacteria, Anaerobic / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D001499:Bayes Theorem; D002944:Circumcision, Male; D006801:Humans; D008297:Male; D010413:Penis / Q000382:microbiology*; D012329:RNA, Bacterial / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D013045:Species Specificity
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S