NCT06940622 · University of Texas Southwestern Medical Center
A Trial of D-mannose for the Prophylaxis of Recurrent Urinary Tract Infections
(DmannoseRCT)
What this study is about
A randomly assigned, where neither patients nor doctors know which treatment is given, compared against an inactive treatment, 12-month study to determine the effectiveness of D-mannose (2g daily) supplementation in rUTI (recurrent urinary tract infection) prevention in post-menopausal women.
View original scientific description
A randomized, double-blind, placebo-controlled, 12-month study to determine the effectiveness of D-mannose (2g daily) supplementation in rUTI (recurrent urinary tract infection) prevention in post-menopausal women.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Female, post-menopausal, age ≥ 55 years old
- Diagnosis of recurrent UTI, defined as ≥ 3 symptomatic culture-proven UTI episodes in 12 months or ≥ 2 in 6 months.
- Currently free from a UTI determined based on absence of symptoms as determined by the UTI symptom assessment questionnaire79 and negative urine culture (\<103 colony forming units per ml of urine).
- Able to attend all follow-up appointments for the study.
- A negative upper and lower urinary tract evaluation, including pelvic examination for pelvic organ prolapse (less than stage 2), measurement of post-void residual (less than 50 ml), and imaging (renal ultrasound and standing voiding cystourethrogram) to exclude kidney stone, hydronephrosis, reflux, or urethral diverticulum.
Exclusion criteria
- Current use of D-mannose. Patients willing to stop taking D-mannose will be offered to join the trial after a 4-week wash-out period.
- Complicated UTIs, including need for catheter drainage or intermittent catheterization, neurogenic bladder, bladder augmentation, or urinary diversion.
- Ongoing supplement use (Box 1). Patients willing to stop taking the listed supplements will be offered to join the trial after a 4-week wash-out period.
- Evidence of upper tract infection (pyelonephritis), including temperature higher than 38°C, flank/lumbar pain or tenderness
- Diagnosis of interstitial cystitis or overactive bladder syndrome
- Prophylactic antibiotics started in the last 3 months and unwilling to discontinue, or intention to start in the next 12 months
- Use of Uromune or other vaccine approaches to reduce rUTI
- Participation in a research study involving an investigational product in the past 12 weeks
- Receipt of phage treatment
- History of chronic diarrhea requiring regular therapy
- Inability to swallow or known history of gastrointestinal malabsorption
- History of recurrent vaginal yeast infections
- Systemic disease precluding enrollment in this study (uncontrolled diabetes with HgA1C above 7, ongoing chemotherapy or immunotherapy, renal insufficiency \[creatinine \> 1.5 g/dl\]), mental or cognitive impairment, weight loss diet requiring excessively large amounts of fluid intake, or other health-related specific diet).
- Nursing home resident
- BMI \>40 Box 1 Supplements to avoid
- Multi-Vitamins and Multi-Mineral capsules
- Specific Vitamins or Minerals (e.g., Calcium, Citrical, Calcium Gummies, Vitamin A, D, Niacin, Pyridoxine, Selenium, Vitamin E, B6, Iron, Omega 3, D3, Magnesium, B-Complex, Women's Ultra MultiVitamin, GNC B-Complex, B-12, PreserVision Areds2, Vitamins D, B Pollen)
- Cranberry Mannose or Cranberry Extract Weight loss products to avoid
- OptiVin Products
- Appetite Suppressants
Where
- Dallas, Texas
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 22, 2025 · Source of record for eligibility and locations