Bladder Bacterial Diversity Differs in Continent and Incontinent Women: A Cross-sectional Study

ABSTRACT BACKGROUND Since the discovery of the bladder microbiome (urobiome), interest has grown in learning whether urobiome characteristics have a role in clinical phenotyping and/or provide opportunities for novel therapeutic approaches for women with common forms of urinary incontinence (UI). OBJECTIVES To test our hypothesis that the bladder urobiome differs between continent women and women affected by UI by assessing associations between UI status and the cultured urobiome. STUDY DESIGN With IRB oversight, transurethral catheterized urine specimens were collected from 309 adult women, who were categorized into three groups using response to the validated Pelvic Floor Distress Inventory (PFDI): Continent Controls (N=150) and 2 Urinary Incontinence (UI cohorts) - Stress Urinary Incontinence (SUI) (N=50) and Urgency Urinary Incontinence (UUI) (N=109). Symptom severity was assessed with the Urinary Distress Inventory (UDI) subscale score of the PFDI. Microbes were assessed by the Expanded Quantitative Urine Culture protocol, which detects the most common bladder microbes (bacteria and yeast). Microbes were identified to the species level by MALDI-TOF mass spectrometry. Alpha diversity indices were calculated for culture-positive samples and compared across the three groups. The association between UDI scores versus alpha diversity indices and species abundance were estimated. RESULTS Participants had a mean age of 53 years (range 22-90); most were Caucasian (65%). Women with UI were slightly older (Control=47, SUI=54, UUI=61). By design, UDI symptom scores differed (Control = 8.43 (10.1), SUI = 97.95 (55.36), UUI = 93.71 (49.12), p CONCLUSIONS In adult women, the composition of the culturable bladder urobiome is associated with UI, regardless of common incontinence subtype. Detection of more unique living microbes was associated with worse incontinence severity. Culturable species richness is significantly greater in the UI cohorts than continent controls.