Background: Overactive bladder describes a syndrome characterized by frequent urges to urinate and increased urination with or without nocturia and with or without urinary incontinence. Overactive bladder affects approximately 13% of older women and thus represents a condition with high prevalence. Affected women report significant limitations in daily life, as well as social isolation. Despite the high occurrence of this condition, therapeutic options are limited, partly because the etiology of this condition is not fully understood. Increasingly, studies suggest an imbalance in the urogenital microbiome as a possible cause of the development of the condition. Therefore, the aim of this study is to test, whether the oral administration of a lactobacillus preparation can lead to a reduction in symptoms.

Design: Randomized controlled study

Methods: Intake of OMNi BiOTiC® 41167 or placebo twice daily for 6 months; swabs (vaginal and urethral) and urine samples from a single-use catheter for microbiome determination at 0, 3, and 7 months.

Outcome: Reduction of subjective symptoms (yes/no) after 3 and 7 months; reduction of Overactive Bladder Symptom Score after 3 and 7 months; change in the urogenital microbiome after 3 and 7 months (comparison of intervention vs. placebo).

Inclusion Criteria:

• diagnosis of overactive bladder syndrome or mixed urinary incontinence with predominance of overactive bladder symptoms

Exclusion Criteria:

• under age 18
• neurogenic overactive bladder