Symptom improvement with mirabegron treatment is associated with urobiome changes in adult women

INTRODUCTION AND HYPOTHESIS: Mirabegron, a beta-3 agonist, is prescribed for urgency urinary incontinence (UUI). We assessed the correlation of symptom improvement with urobiome characteristics in adult women participants prescribed mirabegron for UUI treatment. METHODS: We enrolled participants seeking UUI treatment who selected mirabegron and agreed to participate in this 12-week, open label study conducted at the Female Pelvic Medicine and Reconstructive Surgery Center at Loyola University Medical Center. Following eligibility screening and research consent, participants completed the overactive bladder questionnaire (OAB-Q) and provided a catheterized urine sample at baseline, 4, 8, and 12 weeks. The primary outcome, symptom improvement at 12 weeks, was based on the validated Patient Global Symptom Control questionnaire score to dichotomize symptom response (responder vs nonresponder [PGSC score ≤3]). Urine samples were processed by the Expanded Quantitative Urine Culture (EQUC) protocol. RESULTS: Eighty-three participants (mean age 68 years) completed baseline assessment. Of the 47 participants with primary outcome data and samples analysis, there were 16 responders and 31 nonresponders; responder groups were similar demographically. Living microbes were detected in most participants. There were no significant differences in alpha diversity (within sample) at baseline between groups. However, at the 12-week follow-up, the responder urobiome became significantly richer, with a larger number of genera (p = 0.027) and was significantly more diverse than the nonresponders. CONCLUSIONS: Longitudinal urobiome changes are associated with symptom improvement in adult women being treated with mirabegron for UUI. The mechanism for symptoms improvement may relate to the detected changes in the urobiome and warrants further study.