The urobiome of continent adult women: a cross-sectional study

Objective: To characterise the bladder microbiota of continent adult women. Design: Cross-sectional study of adult women who contributed catheterised urine samples, completed validated symptom questionnaires, and provided demographic data. Setting: US academic medical centre. Population: Well-characterised continent adult women. Methods: Participants contributed symptoms questionnaires, demographic data, and catheterised urine samples that were analysed by enhanced urine culture methodology and 16S rRNA gene sequencing. Main outcome measures: Associations between demographics and microbial community state structures (urotypes, defined by the dominant taxon of each specimen). Results: The bladder microbiota (urobiome) of a control group of 224 continent women were characterised, demonstrating variability in terms of urotype. The most common urotype was Lactobacillus (19%), which did not differ with any demographic. In contrast, the Gardnerella (P < 0.001) and Escherichia (P = 0.005) urotypes were more common in younger and older women, respectively. Conclusions: For urobiome research, enhanced culture methods and/or DNA sequencing are the preferred techniques for bacterial detection. The interpretation of clinical tests, such as the standard urine culture, should incorporate the knowledge that some women have Gardnerella or Escherichia urotypes without evidence of any clinical disorder. Clinical care strategies should preserve or restore the beneficial effects of the native urobiome, as disruption of that microbial community could result in unintended vulnerability to uropathogen invasion or opportunistic pathogen overgrowth. Longitudinal studies of urobiome responses to therapies should be encouraged. Tweetable abstract: In continent adult women bladder microbiome composition differs by age, with relevance for clinical practice.