umigs_vaginal_microbiota_composition_study
The vaginal microbiome in reproductive age women
Targeted Gene Survey
The means by which vaginal microbiomes help prevent urogenital diseases in women and maintain health are poorly understood. To gain insight to this the vaginal bacterial communities of 396 asymptomatic North American women that represented four ethnic groups (White, Black, Hispanic and Asian) were sampled and the species composition was characterized by pyrosequencing of barcoded 16S rRNA genes. The communities clustered into five groups; four were dominated by Lactobacillus iners, L. crispatus, L. gasseri or L. jensenii, while the fifth had lower proportions of lactic acid bacteria and higher proportions of strictly anaerobic organisms. A key ecological function – the production of lactic acid – was conserved in all communities. The proportions of each community group varied among the four ethnic groups and these differences were statistically significant (?2 = 36.8 on 10 df, P<.0001). Moreover, the vaginal pH of women in different ethnic groups also differed and was higher in Hispanic (pH 5.0±0.59) and Black (pH 4.7±1.04) women as compared to Asian (pH 4.4±0.59) and White (pH 4.2±0.3) women. Phylotypes with correlated relative abundances were found in all communities, and these patterns were associated with either high or low Nugent scores that are used as a diagnostic for bacterial vaginosis. The inherent differences within and between women in different ethnic groups strongly argues for a more refined definition of the kinds of bacterial communities normally found in healthy women, and the need to appreciate differences between individuals so they can be taken into account in risk assessment and disease diagnosis.