title: Free glycogen in vaginal fluids is associated with Lactobacillus colonization and low vaginal pH.
abstract: OBJECTIVE
  Lactobacillus dominates the lower genital tract microbiota of many women, producing a low vaginal pH, and is important for healthy pregnancy outcomes and protection against several sexually transmitted pathogens. Yet, factors that promote Lactobacillus remain poorly understood. We hypothesized that the amount of free glycogen in the lumen of the lower genital tract is an important determinant of Lactobacillus colonization and a low vaginal pH.
  
  
  METHODS
  Free glycogen in lavage samples was quantified. Pyrosequencing of the 16S rRNA gene was used to identify microbiota from 21 African American women collected over 8-11 years.
  
  
  RESULTS
  Free glycogen levels varied greatly between women and even in the same woman. Samples with the highest free glycogen had a corresponding median genital pH that was significantly lower (pH 4.4) than those with low glycogen (pH 5.8; p<0.001). The fraction of the microbiota consisting of Lactobacillus was highest in samples with high glycogen versus those with low glycogen (median = 0.97 vs. 0.05, p<0.001). In multivariable analysis, having 1 vs. 0 male sexual partner in the past 6 months was negatively associated, while BMI ≥30 was positively associated with glycogen. High concentrations of glycogen corresponded to higher levels of L. crispatus and L. jensenii, but not L. iners.
  
  
  CONCLUSIONS
  These findings show that free glycogen in genital fluid is associated with a genital microbiota dominated by Lactobacillus, suggesting glycogen is important for maintaining genital health. Treatments aimed at increasing genital free glycogen might impact Lactobacillus colonization.
authors.affiliation: Department of Immunology/Microbiology, Rush University, Chicago, Illinois, United States of America.
authors.forename: Paria
authors.initials: P
authors.lastname: Mirmonsef
authors.affiliation: The CORE Center, Cook County Health & Hospital System, Chicago, Illinois, United States of America.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Hotton
authors.affiliation: Department of Immunology/Microbiology, Rush University, Chicago, Illinois, United States of America.
authors.forename: Douglas
authors.initials: D
authors.lastname: Gilbert
authors.affiliation: Department of Immunology/Microbiology, Rush University, Chicago, Illinois, United States of America.
authors.forename: Derick
authors.initials: D
authors.lastname: Burgad
authors.affiliation: Department of Immunology/Microbiology, Rush University, Chicago, Illinois, United States of America.
authors.forename: Alan
authors.initials: A
authors.lastname: Landay
authors.affiliation: The CORE Center, Cook County Health & Hospital System, Chicago, Illinois, United States of America.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Weber
authors.affiliation: The CORE Center, Cook County Health & Hospital System, Chicago, Illinois, United States of America.
authors.forename: Mardge
authors.initials: M
authors.lastname: Cohen
authors.affiliation: Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Jacques
authors.initials: J
authors.lastname: Ravel
authors.affiliation: Department of Immunology/Microbiology, Rush University, Chicago, Illinois, United States of America.
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Spear
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D005260:Female; D006003:Glycogen / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000302:isolation & purification*; D064307:Microbiota / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012725:Sexual Behavior; D014621:Vagina / Q000378:metabolism* / Q000382:microbiology* / Q000502:physiology; D016585:Vaginosis, Bacterial; D055815:Young Adult
chemical_list: D012336:RNA, Ribosomal, 16S; D006003:Glycogen