Microbiome-Modulating Prophylaxis RCT: Antibiotic vs Gynoflor in Postmenopausal Women With Recurrent Cystitis

Evaluating Urinary Microbiome Modulation :An RCT of Antibiotic vs Gynoflor Prophylaxis in Postmenopausal Women With Recurrent Cystitis

Microbiome-Modulating Prophylaxis RCT: Antibiotic vs Gynoflor in Postmenopausal Women With Recurrent Cystitis (NCT07186465) is a Phase 4 interventional studying Cystitis, Recurrent and Urinary Tract Infections, sponsored by Mahidol University. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

This open-label, parallel-group randomized controlled trial compares two prophylaxis strategies for recurrent urinary tract infection (rUTI) in postmenopausal women: (1) nightly oral nitrofurantoin 100 mg for 6 months versus (2) a vaginal tablet containing Lactobacillus with ultra-low-dose estriol (Gynoflor: nightly for 14 days, then twice weekly to month 6). Participants (≥40 years) are randomized 1:1 in computer-generated blocks and followed for 6 months. The primary endpoint is the proportion with rUTI recurrence within 6 months. Secondary endpoints include time to first recurrence, antibiotic resistance in breakthrough infections, change in lower urinary tract symptoms (Thai RUTISS), and urinary microbiome measures (Lactobacillus dominance and community diversity by qPCR and 16S rRNA). Key assessments occur at baseline and month 6 (urinalysis, culture, urinary microbiome sampling, and kidney function). Adherence and adverse events are captured via twice-weekly phone/Line contacts. Approximately 100 participants (50 per arm) will be enrolled as a feasibility-sized pilot.

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 100 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Cystitis, Recurrent subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: - Female, postmenopausal, age ≥40 years - Clinical history of recurrent urinary tract infection (rUTI) as assessed by the investigator - Able and willing to take assigned prophylaxis for 6 months - Able to attend baseline and Month 6 study visits and provide urine samples - Able to provide written willing to sign a consent form - Willing and able to complete twice-weekly phone/LINE follow-ups Who Should NOT Join This Trial: - Current symptomatic UTI at enrollment (may be treated and reconsidered after resolution) - Known hypersensitivity or contraindication to nitrofurantoin or to the Lactobacillus/estriol vaginal tablet (Gynoflor) or their excipients; significant renal impairment or other label-based contraindications to nitrofurantoin per local practice - Planned urologic surgery or procedure expected during the 6-month study period - Recent bacterial vaginosis (e.g., within the past month) or active vulvovaginal skin disorders precluding vaginal product use - History of hormone-dependent malignancy (e.g., breast, uterine, or cervical cancer) or unexplained abnormal vaginal bleeding - Significant liver disease (e.g., active hepatitis) or other conditions judged by the investigator to make participation unsafe - Participation in another interventional trial that could interfere with outcomes - Withdrawal of consent or severe adverse event requiring discontinuation Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Female, postmenopausal, age ≥40 years * Clinical history of recurrent urinary tract infection (rUTI) as assessed by the investigator * Able and willing to take assigned prophylaxis for 6 months * Able to attend baseline and Month 6 study visits and provide urine samples * Able to provide written informed consent * Willing and able to complete twice-weekly phone/LINE follow-ups Exclusion Criteria: * Current symptomatic UTI at enrollment (may be treated and reconsidered after resolution) * Known hypersensitivity or contraindication to nitrofurantoin or to the Lactobacillus/estriol vaginal tablet (Gynoflor) or their excipients; significant renal impairment or other label-based contraindications to nitrofurantoin per local practice * Planned urologic surgery or procedure expected during the 6-month study period * Recent bacterial vaginosis (e.g., within the past month) or active vulvovaginal skin disorders precluding vaginal product use * History of hormone-dependent malignancy (e.g., breast, uterine, or cervical cancer) or unexplained abnormal vaginal bleeding * Significant liver disease (e.g., active hepatitis) or other conditions judged by the investigator to make participation unsafe * Participation in another interventional trial that could interfere with outcomes * Withdrawal of consent or severe adverse event requiring discontinuation

Treatments Being Tested

DRUG

Nitrofurantoin

Nightly oral nitrofurantoin 100 mg for 6 months as prophylaxis for recurrent UTI in postmenopausal women. If symptomatic UTI occurs, treat per standard care and, once resolved, continue assigned prophylaxis to complete 6 months. Monitoring per protocol: baseline and month-6 visits with urinalysis, urine culture, urinary microbiome, and kidney function; twice-weekly phone/Line check-ins for adherence, symptoms, and adverse events.

DRUG

Gynoflor

Vaginal tablet containing Lactobacillus with ultra-low-dose estriol. Insert 1 tablet nightly for 14 days, then twice weekly through month 6 as prophylaxis against recurrent urinary tract infection. If a symptomatic UTI occurs, treat per standard of care; after resolution, continue assigned prophylaxis to complete 6 months. Monitoring identical to comparator.

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Faculty of Medicine Ramathibodi Hospital Mahidol University

Bangkok, Phayatai Ratchathewi, Thailand

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT07186465), the sponsor (Mahidol University), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT07186465 clinical trial studying?

Who can participate in NCT07186465?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT07186465?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT07186465. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT07186465. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.