Urobiome community type linked with more severe incontinence episodes

These results indicated more severe total and urge incontinence episodes among women with urobiomes with fewer Lactobacilli and more diverse bacteria.

A recent American Journal of Obstetrics & Gynecology study indicates that urobiome community types containing fewer Lactobacilli and greater bacterial diversity are associated with more severe urinary incontinence episodes.¹

Bacteria has been categorized into various niches, including the bladder niche and adjacent vaginal niche in women. Sequencing methods allow for urothelial and squamous intracellular bacteria to be identified. These bacteria may serve as reservoirs for chronic conditions such as urinary tract infection (UTI).

As bacteria are not isolated, it is important to evaluate bacteria within their community structure. Evaluating vaginal and urinary microbiota associated with UI may allow bacteria associated with UI severity to be identified.

Investigators conducted a study to evaluate bacteria associated with UI severity. Women enrolled in the Effects of Surgical Treatment Enhanced with Exercise for Mixed Urinary Incontinence trial were included in the analysis.

Exclusion criteria included recent antibiotic use, current probiotic use, and complaints of dysuria, clinically suggestive UTI, or dipstick-positive urine. Samples from women with and without UI were included for improved representation of microbiome profiles.

The 19-item Urogenital Distress Inventory (UDI) and a 3-day bladder diary were used to evaluate baseline mixed urinary incontinence (MUI). Severity measures included UDI irritative symptoms, UDI stress symptoms, total of all subscales from the UDI, and 3-day urge leaks, stress leaks, and total leaks per day.

Transurethral catheterization was employed to collect urine samples, while swabs (ESwab; Copan Diagnostics, Murietta, CA) were used to collect vaginal samples.

There were 210 participants included in the final analysis, 126 of whom were MUI cases and 84 were controls. The mean age among cases and controls was 53 years. Of cases, 73% were White and 52.4% were postmenopausal.

A mean 5.6 leakage episodes per day and mean UDI score of 179.7 was reported among cases at the time of sample collection. As similar community compositions were reported between MUI cases and controls, investigators focused on evaluating relationships between urobiome community types and UI severity.

There were 6 communities identified: a high Lactobacillus group 1, moderate Lactobacilli and Gardnerella group 2, fewer Lactobacilli and greater proteobacteria group 3, similar to group 3 but with more Lactobacilli and less proteobacteria group 4, similar Lactobacilli and Gardnerella to group 2 and moderate Prevotella and Escherichia-Shigella group 5, and high Escherichia-Shigella group 6.

Greater genera were observed in groups 3, 4, and 5, indicating these groups had increased alpha diversity compared to other groups. Additionally, decreased richness was observed in groups 1, 2, and 6 vs these groups.

A greater association with total leaks was observed in group 3 with 2.67 daily leaks, as well as urge leaks with 1.75 daily leaks. Group 3 was also associated with UI severity and had high levels of Tepidimonas.

Notably, consistent Tepidimonas was not observed in the control samples. When removing Tepidimonas, a community with low Lactobacillus and high proteobacteria was associated with 3.39 daily total leaks and 2.05 daily urge leaks, indicating a significant association.

These results indicated more severe total and urge incontinence episodes among women with urobiomes with fewer Lactobacilli and more diverse bacteria. Investigators concluded more research is needed to determine if Lactobacillus predominance impacts UI severity.

REFERENCE

1. Carnes MU, Siddiqui NY, Karstens L, et al. Urinary microbiome community types associated with urinary incontinence severity in women. Am J Obstet Gynecol. 2024;230:344.e1-20.doi:10.1016/j.ajog.2023.10.036