Alterations in vaginal and urinary microbiota among women of different ages based on a cross-sectional study from Health Examination Center

Abstract

Abstract Background: Role of vaginal and urinary microbiomes have gaining increasing concern in many health aspects. The dynamic change of these bacterial communities of healthy females throughout their life remained poorly understood, and how vaginal and urinary microbiota interact with each other requires further exploration. Therefore, we conducted a cross-sectional study to examine vaginal and urinary microbiota of healthy female of different age based on 16S rRNA gene sequencing. Results: A total of 348 vaginal swab samples and 209 urine samples were collected and 90 pairs of samples were matched. The average age of all participants was 44.76±0.55 years old. All the participants were further divided into 5 age groups: <=30 years old (G1), 31-40 years old (G2), 41-50 years old (G3), 51-60 years old (G4), >60 years old (G5). 16s rRNA analysis of vaginal and urinary microbiota identified 3458 OTUs and 1282 OTUs respectively. Lactobacillus was the most abundant genus in both vaginal and urinary microbiota of female under 40 years old, but the abundance decreased with age. The diversity of both vaginal and urinary microbiota increased with age. Moderate to high Pearson correlations were found in some genera presenting in both sites, including Lactobacillus (R2=0.7735, P≤0.001), Gardnerella (R2=0.6698, P≤0.001), Actinomyces (R2=0.6118, P≤0.001), while vaginal Anaerococcus was also positively associated with urine Peptoniphilus (R2=0.6352, P≤0.001). Urine Lactobacillus was negatively associated with Streptococcus (R2=-0.62275, P≤0.001), Peptoniphilus (R2=-0.6097, P≤0.001), and Finegoldia (R2=-0.60703, P≤0.001). Age and the status of menopause appeared to be the most dominant clinical factors impact both vaginal and urinary microbiota. Conclusions: Significant variations of vaginal and urinary microbiota in different age groups were observed. Lactobacillus was the most dominant genus in both in female under 40 and correlated highly between different samples. The diversity increased, with the decrease of Lactobacillus dominance in both vaginal and urinary microbiota after 40 and the change was especially significant in the perimenopausal period. This change may be partially related to the susceptibility of some urogenital diseases of the postmenstrual women, but more studies on microbiota of patients are required to further explore it.