UROBIOME community types with fewer Lactobacilli and greater bacterial diversity are associated with more severe urinary incontinence (UI) episodes in females, according to recent findings.
A team conducted a secondary cross-sectional analysis to investigate whether specific types of urinary or vaginal microbiome communities correlate with the severity of UI. The study included 126 participants from the Effects of Surgical Treatment Enhanced With Exercise for Mixed Urinary Incontinence trial, and 84 controls (n=210; mean age: 53 years; 73% White; 52.4% post-menopausal).
UI severity was measured using a 3-day bladder diary and 19-item Urogenital Distress Inventory (UDI), including 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. Catheterised urine samples and vaginal swabs were collected to assess urinary and vaginal microbiomes, and sequencing of the 16S rRNA V4 to V6 variable regions identified bacterial taxa to the genus level.
The study identified six urinary microbiome community types, characterised by varying levels of common genera, such as Lactobacillus, Gardnerella, and Prevotella. The analysis of UI severity identified a Lactobacillus-dominated reference group with the highest abundance of Lactobacillus (mean relative abundance of 76%). Findings revealed that a community characterised by fewer Lactobacilli and greater alpha diversity was associated with higher total of both UI and urgency UI episodes, compared to the reference group. Specifically, this community had 2.67 daily leaks (95% confidence interval: 0.76–4.59; P=0.007) for total UI episodes, and 1.75 daily leaks (95% confidence interval: 0.24–3.27; P=0.02) for urgency episodes.
No significant association was found between community type and stress UI episodes or UDI scores. Vaginal community types did not show any association with UI severity.
The authors noted that the exact reasons for this association between urinary microbiome and UI severity remain to be determined. Further research could elucidate whether mixed UI severity is due to lesser predominance of Lactobacillus, greater presence of other non-Lactobacillus genera, or the complement of bacteria consisting of urobiome community types.
