Efficacy of Probiotics for OAB Patients With Anxiety

June 3, 2026 updated by: Qilu Hospital of Shandong University

Evaluating the Efficacy of Probiotics as an Adjunct to Behavioral Therapy in Patients With Overactive Bladder (OAB) and Anxiety Symptoms: A Randomized, Double-Blind, Placebo-Controlled Trial

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:

  1. Does taking probiotics lower the number of times participants need to urinate in a 24-hour period?
  2. Does taking probiotics lower participants' anxiety levels?

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:

  1. Take probiotics or a placebo twice a day for 12 weeks.
  2. Learn and practice bladder training using a manual and educational videos.
  3. Keep a 3-day diary of when they urinate and what they drink at the beginning, middle, and end of the study.
  4. Answer survey questions about their anxiety and quality of life during clinic visits.
  5. Provide urine samples for routine checkups to ensure they do not have infections.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Interventional

Enrollment (Estimated)

218

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
    • Shandong
      • Jinan, Shandong, China
        • Qilu Hospital of Shandong University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Aged between 18 and 80 years old (inclusive).
  2. Able to understand study-related instructions and independently complete the required questionnaires.
  3. Able to provide written informed consent and willing to comply with all study requirements, including completing diaries/questionnaires and refraining from taking any other probiotic or prebiotic supplements during the 3-month study period.
  4. Meet the diagnostic criteria for Overactive Bladder (OAB) as defined by the International Continence Society (ICS) (urgency as the core symptom, with or without urgency urinary incontinence, frequency, and nocturia); have an Overactive Bladder Symptom Score (OABSS) ≥ 6; and have a daytime voiding frequency of ≥ 8 times.
  5. Have a preliminary diagnosis of "Generalized Anxiety Disorder" or "Anxiety state" assessed by a psychiatrist or trained investigator according to DSM-5 or ICD-10 criteria, or have a Generalized Anxiety Disorder-7 (GAD-7) scale score ≥ 5.
  6. If previously using any over-the-counter medications or other products for anxiety relief (e.g., magnesium, melatonin, anticholinergic drugs) or receiving psychotherapy, these must have been discontinued for at least 4 weeks prior to randomization and must remain completely discontinued throughout the entire study period.

Exclusion Criteria:

  1. Presence of organic diseases of the urinary system (e.g., urinary tract obstruction, tumors, stones, acute infection, interstitial cystitis, stress urinary incontinence).
  2. Neurogenic bladder caused by neurological diseases or a history of pelvic surgery.
  3. Use of antibiotics, probiotics, or prebiotics within the past 1 month prior to screening.
  4. Any adjustment to medications used for treating OAB or anxiety within the past 2 weeks prior to screening.
  5. Pregnant or lactating women, or individuals with a known allergy to any components of the study preparation.
  6. Suffering from other severe psychiatric/psychological disorders or severe systemic diseases (e.g., uncontrolled diabetes mellitus, severe obesity).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Probiotics + Standard Behavioral Therapy
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
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.
Other Names:
  • Lactobacillus acidophilus
  • Lactobacillus plantarum
  • Lactobacillus casei
Experimental: Placebo + Standard Behavioral Therapy
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
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.
Other Names:
  • Maltodextrin powder

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in the Mean Number of Micturitions per 24 Hours
Time Frame: Baseline (Week 0), Week 4, Week 8, and Week 12
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.
Baseline (Week 0), Week 4, Week 8, and Week 12

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in the Mean Number of Urgency Episodes per 24 Hours
Time Frame: Baseline (Week 0), Week 4, Week 8, and Week 12
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.
Baseline (Week 0), Week 4, Week 8, and Week 12
Change in the Mean Number of Urgency Urinary Incontinence (UUI) Episodes per 24 Hours
Time Frame: Baseline (Week 0), Week 4, Week 8, and Week 12
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.
Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Mean Volume Voided per Micturition
Time Frame: Baseline (Week 0), Week 4, Week 8, and Week 12
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.
Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Generalized Anxiety Disorder-7 (GAD-7) Score
Time Frame: Baseline (Week 0), Week 4, Week 8, and Week 12
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.
Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Overactive Bladder Symptom Score (OABSS)
Time Frame: Baseline (Week 0), Week 4, Week 8, and Week 12
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.
Baseline (Week 0), Week 4, Week 8, and Week 12
Change in Overactive Bladder Questionnaire (OAB-q) Score
Time Frame: Baseline (Week 0) and Week 12
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.
Baseline (Week 0) and Week 12
Patient Global Impression of Improvement (PGI-I) Score
Time Frame: Week 12
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.
Week 12
Incidence of Treatment-Emergent Adverse Events (TEAEs)
Time Frame: From Baseline (Week 0) up to Week 12
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.
From Baseline (Week 0) up to Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Qilu Hospital of Shandong University

Investigators

  • Study Chair: Yuchao Sun, Bachelor, Shandong University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2028

Study Registration Dates

First Submitted

June 3, 2026

First Submitted That Met QC Criteria

June 3, 2026

First Posted (Actual)

June 9, 2026

Study Record Updates

Last Update Posted (Actual)

June 9, 2026

Last Update Submitted That Met QC Criteria

June 3, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • KYLL-2026-03-006-1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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