Characterization of the GU microbiome in women with self‐perceived bladder health over the life course
Authors: Mueller Margaret G. , Das Promi , Andy Uduak , Dieter Alexis A. , Dwarica Denicia , Kirby Anna C. , Shepherd Jonathan P. , Gregory W. Thomas , Amundsen Cindy L. , Kenton Kimberly 
Published: October 2022

Background

A variety of factors influence bladder health, including environmental factors, life experiences, biologic foundations, and coexistent medical conditions. A biologically diverse microbial community exists in the urine that is likely influenced by the microbial inhabitants of the vagina. The relationship between the genitourinary (GU) microbiome and self‐perceived bladder health is unknown.

Objective

To longitudinally define the GU microbiome in women with self‐percieved bladder health sampled across multiple time points over a year.

Study Design

Women with no reported lower urinary tract dysfunction or symptoms (LUTS) were recruited from six clinical sites and assessed every 6 weeks for 1 year. Voided urine and vaginal samples were longitudinally collected. Self‐perceived bladder health was assessed with select items from the LURN comprehensive assessment of self‐reported urinary symptoms (CASUS) tool. We defined four life phases as follows: young (18−34 years, nulliparous), midlife (35−45 years, menstruating), transitional (46−60 years, perimenopausal), mature (>60 years, not using vaginal and/or systemic hormone replacement therapy). DNA was extracted from samples, and the V4 region of the 16S rRNA gene was amplified with region‐specific primers. The 16S rRNA sequencing on an Illumina NovaSeq. Microbial beta‐diversity was calculated using DEICODE to identify microbial taxa that cluster in the samples. Longitudinal volatility analysis was performed using the gemelli plugin. Log‐abundance ratios of microbial features were explored and visualized in Qurro.

Results

Fifty‐four (N = 16 young, N = 16 midlife, N = 15 transitional, N = 7 mature) women were enrolled and provided baseline data. Most women in each life phase (93%−98%) continued to report self‐perceived bladder health throughout the 1‐year follow‐up as assessed by CASUS items. Temporal‐based microbial diversity of urinary and vaginal microbiome remained relatively stable over 1 year in all subjects. The GU microbiomes of mature women were distinct and microbially diverse from that of young, midlife, and transitional women, with genera of Gardnerella, Cupriavidus, and Dialister contributory to the microbial features of the mature microbiome. The mature GU microbiome was statistically different (p < 0.0001) from the midlife, transitional, and young microbiome for the log ratio of Gardnerella and Cupriavidus (in the numerator) and Lactobacillus (in the denominator) for voided samples and Gardnerella and Dialister (in the numerator) and Lactobacillus (in the denominator) for vaginal samples. Differences in the GU microbiome were also demonstrated via longitudinal beta‐diversity between women developing urinary frequency as reported by CASUS responses or objectively on bladder diary compared to women without urinary frequency.

Conclusion

In women with a self‐perceived healthy bladder, the GU microbiome remained stable in all age groups over a 1 year period. Differences were seen with respect to life phase, where mature women were distinct from all other groups, and with respect to self‐reported LUTS.