A urobiome community type with fewer Lactobacilli and more diverse bacteria is associated with more severe urinary incontinence (UI) episodes vs a type with high predominance of a single genus, Lactobacillus, according to a recent study published in the American Journal of Obstetrics & Gynecology.
Takeaways
- The study suggests that urobiomes with fewer Lactobacilli and a more diverse range of bacteria are associated with more severe urinary incontinence episodes.
- By evaluating the composition of both vaginal and urinary microbiota, researchers identified distinct community types correlated with differing levels of urinary incontinence severity.
- Groups with increased alpha diversity and richness, particularly those with greater genera diversity, exhibited higher urinary incontinence severity, indicating a potential link between bacterial diversity and symptom severity.
- Tepidimonas, a genus not commonly found in control samples, was notably associated with more severe urinary incontinence episodes, suggesting a potential marker for identifying individuals at risk for more severe symptoms.
- While the study sheds light on the relationship between urobiome composition and urinary incontinence severity, further research is needed to determine the impact of Lactobacillus predominance on symptom severity and to explore potential interventions targeting urobiome diversity for managing urinary incontinence.
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
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
