An interventional study of Multi-strain Probiotic Compound and Placebo in Overactive Bladder (OAB), sponsored by Qilu Hospital of Shandong University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-06-09.
Sponsored by Qilu Hospital of Shandong University · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to learn if probiotics can help improve symptoms in adults with overactive bladder (OAB) and anxiety. The main questions it aims to answer are:
Researchers will compare probiotics to a placebo (a look-alike powder that contains no active bacteria) to see if the probiotics work better to treat OAB and anxiety when both groups also use standard behavioral therapy (like bladder training).
Participants will:
Background and Scientific Rationale Overactive bladder (OAB) is a prevalent chronic condition that severely impairs patients' quality of life. Accumulating epidemiological evidence highlights a high comorbidity rate between OAB and psychological disorders, particularly anxiety. These two conditions often exacerbate each other, forming a vicious pathological cycle: anxiety heightens central sensitivity to bladder fullness, while unpredictable urinary urgency worsens psychosocial stress. Current pharmacological mainstays, such as antimuscarinics and β3-adrenoceptor agonists, primarily target local bladder smooth muscle. They often fail to address the underlying psychological comorbidities and are frequently associated with intolerable adverse effects (e.g., dry mouth, constipation), leading to high discontinuation rates. There is an urgent clinical need for systemic, well-tolerated therapeutic strategies that address both physical and emotional symptoms.
Theoretical Framework: The Brain-Gut-Bladder Axis This trial is grounded in the emerging "Brain-Gut-Bladder Axis" model. Chronic stress and anxiety can trigger systemic low-grade inflammation and alter the gut microbiome, which in turn influences peripheral neural pathways and bladder afferent signaling. We hypothesize that targeted microecological interventions using specific "psychobiotics" can modulate this axis. Scientific literature suggests that select probiotic strains can communicate with the central nervous system via the vagus nerve and systemic metabolites. By doing so, they may downregulate the hypothalamic-pituitary-adrenal (HPA) axis, optimize the levels of inhibitory neurotransmitters (such as GABA and Serotonin), and suppress neurogenic inflammation.
Intervention Strategy To test this hypothesis, this study employs an "add-on" clinical trial design. All enrolled participants will receive standardized behavioral therapy, which remains the fundamental first-line treatment for OAB, consisting of bladder training and lifestyle modification instructions. On top of this standard of care, participants will be randomized to receive either a multi-strain probiotic compound or a visually and organoleptically matched placebo.
The active intervention utilizes a compound of food-grade, widely recognized safe bacterial strains: Lactobacillus plantarum, Bacillus coagulans, Lactobacillus casei, and Lactobacillus acidophilus. These specific strains were selected for their documented potential in immune regulation, anti-inflammatory properties, and central nervous system modulation.
Study Execution and Clinical Significance Throughout the 12-week intervention period, the study avoids invasive procedures or the collection of extensive biological samples for complex genomic sequencing. Instead, it relies on validated clinical instruments, patient diaries, and standard routine urinalysis (strictly for safety monitoring and infection exclusion) to track treatment trajectories.
By bridging urology and neurogastroenterology, this study seeks to provide high-quality, evidence-based data for a paradigm shift in OAB management. If proven effective, this probiotic-assisted approach will offer a safe, non-pharmacological "mind-body" co-treatment option, potentially breaking the anxiety-urgency cycle and significantly improving the comprehensive well-being of a difficult-to-treat patient population.
858 studies on the registry are indexed under Urinary Bladder, Overactive; 127 are open to participants now.
This study's planned enrollment of 218 is above the median of 70 across 649 interventional studies indexed under Urinary Bladder, Overactive.
Browse Urinary Bladder, Overactive studies →Qilu Hospital of Shandong University is the lead sponsor of 310 studies on the registry; 188 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants assigned to this arm will receive a probiotic powder compound containing Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus acidophilus. The probiotic powder will be dissolved in a glass of water and taken orally once a day for 12 weeks. In addition to the probiotic, participants will receive standard behavioral therapy for overactive bladder (OAB) administered by trained clinical staff. This comprehensive, individualized therapy includes six core modules: bowel management (e.g., dietary fiber intake), fluid and diet modification (e.g., limiting caffeine and other bladder irritants), weight and smoking management, bladder training (including voiding diaries, delayed voiding, and urge suppression techniques), pelvic floor muscle training (PFMT), and personalized follow-up adjustments.
Dietary Supplement: Multi-strain Probiotic Compound
Participants assigned to this arm will receive a placebo powder dissolved in a glass of water, taken orally once a day for 12 weeks. The placebo is composed of inert excipients (such as maltodextrin) and contains no active bacteria, but is identical to the active probiotic product in color, texture, taste, and solubility. In addition to the placebo, participants will receive the exact same standard behavioral therapy for OAB as the experimental group. This comprehensive, individualized therapy includes six core modules: bowel management, fluid and diet modification (e.g., limiting bladder irritants), weight and smoking management, bladder training (including voiding diaries, delayed voiding, and urge suppression techniques), pelvic floor muscle training (PFMT), and personalized follow-up adjustments.
Other: Placebo
The active intervention consists of a probiotic powder containing Lactobacillus plantarum DY-1, Lactobacillus casei KDB-LC, and Lactobacillus acidophilus KDB-03. The powder is to be dissolved in a glass of water and administered orally once a day for 12 weeks.
Also known as: Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus
An inactive placebo powder composed of inert excipients (maltodextrin) containing no active bacteria. It is visually and organoleptically identical to the active probiotic product (matching in color, texture, taste, and solubility). The powder is to be dissolved in a glass of water and administered orally once a day for 12 weeks.
Also known as: Maltodextrin powder
Change in the Mean Number of Micturitions per 24 Hours
Assessed using a 3-day voiding diary. Participants record every voiding event over 3 consecutive days. The metric is calculated as the total number of micturitions divided by 3 to determine the mean daily frequency. A negative change (decrease) from baseline indicates an improvement in overactive bladder symptoms.
Time frame: Baseline (Week 0), Week 4, Week 8, and Week 12
Change in the Mean Number of Urgency Episodes per 24 Hours
Assessed using a 3-day voiding diary, where participants rate urgency for each voiding event on a 0-5 scale (0=no urgency, 5=severe urgency). The metric is calculated as the mean number of urgency episodes per day. A decrease in the number of episodes from baseline indicates symptom improvement.
Time frame: Baseline (Week 0), Week 4, Week 8, and Week 12
Change in the Mean Number of Urgency Urinary Incontinence (UUI) Episodes per 24 Hours
Assessed using a 3-day voiding diary, recording urine leakage (in mL). UUI is defined as the involuntary leakage of urine associated with urgency. The metric is calculated as the mean number of UUI episodes per day. A decrease from baseline indicates symptom improvement.
Time frame: Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Mean Volume Voided per Micturition
Assessed using a 3-day voiding diary. The value is calculated by dividing the total volume of urine voided over the 3-day period by the total number of micturitions during that same period, measured in milliliters (mL). An increase from baseline indicates improved functional bladder capacity.
Time frame: Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Generalized Anxiety Disorder-7 (GAD-7) Score
The GAD-7 is a standardized questionnaire used to measure the severity of anxiety. It consists of 7 items, each scored from 0 (not at all) to 3 (nearly every day). The total score ranges from 0 to 21. Higher scores indicate greater severity of anxiety symptoms. A decrease in the total score from baseline indicates clinical improvement.
Time frame: Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Overactive Bladder Symptom Score (OABSS)
The OABSS is a validated 4-item questionnaire assessing daytime frequency, nighttime frequency, urgency, and urgency urinary incontinence. The total score ranges from 0 to 15, derived from the sum of the four symptom scores. A higher score indicates more severe OAB symptoms. A decrease from baseline reflects clinical improvement.
Time frame: Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Overactive Bladder Questionnaire (OAB-q) Score
Assessed using a 13-item health-related quality of life and symptom bother questionnaire (OAB-q). Each item is rated on a 6-point Likert scale from 1 (never) to 6 (all the time). The total score ranges from 13 to 78. A higher score indicates worse symptom bother and a greater negative impact on the patient's quality of life. A decrease in score indicates improvement.
Time frame: Baseline (Week 0) and Week 12
Patient Global Impression of Improvement (PGI-I) Score
The PGI-I is a single-item questionnaire assessing the patient's overall perception of their OAB symptom condition compared to baseline. Participants rate their condition on a 7-point scale ranging from 1 ("very much better") to 7 ("very much worse"). A lower score indicates a better treatment outcome.
Time frame: Week 12
Incidence of Treatment-Emergent Adverse Events (TEAEs)
Safety and tolerability will be evaluated by monitoring the frequency, severity, and relatedness of adverse events (AEs) and serious adverse events (SAEs) reported by participants throughout the study period.
Time frame: From Baseline (Week 0) up to Week 12
Plan to share: Undecided
Start is estimated for Jul 2026; primary completion for Dec 2028, 29 months later.
Of 133 non-industry interventional studies with no phase under Urinary Bladder, Overactive, half reached primary completion within 22 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 40. This study's planned 29 months is above that.
Counting every sponsor, half of 174 studies reached it within 19 months; a quarter within 10 and three quarters within 40.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Lactobacillus plantarum
Qilu Hospital of Shandong University →