Study to Evaluate Efficacy and Safety of Gyntima® Balance in Preventing Recurrences of Bacterial Vaginosis (GYNBAL-RBV)

A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Gyntima® Balance in Preventing Recurrences of Bacterial Vaginosis.

The vagina is a dynamic muscular organ whose health relies on a Lactobacillus-dominant microbiota that maintains low pH and protects against infections. Bacterial vaginosis (BV) is the most common vaginal imbalance in women of reproductive age, caused by depletion of protective Lactobacillus species and overgrowth of anaerobic bacteria such as Gardnerella vaginalis. BV affects an estimated 23-29 percentage of women globally (10-30 percentage in India) and is associated with discharge, odor, discomfort, and significant risks including recurrent disease, adverse reproductive outcomes, and increased susceptibility to STIs. Although antibiotics are effective for acute treatment, recurrence rates are high (50-60 percentage within 12 months), highlighting an unmet need for preventive strategies.

Probiotics, particularly Lactobacillus species, have emerged as promising options to restore vaginal microbiota balance and reduce BV recurrence. Lactobacillus gasseri is a natural vaginal commensal with antimicrobial activity against BV pathogens and the ability to lower vaginal pH. L. gasseri KABP®064 has demonstrated vaginal colonization after oral administration, good tolerability, and potential to promote vaginal health.

The present randomized, double-blind, placebo-controlled trial aims to evaluate the efficacy and safety of oral L. gasseri KABP®064 in preventing BV recurrence over six months following standard antibiotic therapy. Outcomes include recurrence rates and timing, symptom severity, microbiological balance, inflammation markers, and patient-reported vaginal health, supporting a microbiome-focused, non-antibiotic approach to BV recurrence prevention.

Study Overview

• Status: Not yet recruiting
• Conditions: Vaginosis, Bacterial; Bacterial Vaginosis; Bacterial Vaginosis (BV)
• Intervention / Treatment: Dietary supplement: Lactobacillus gasseri KABP®064 10e9 CFU/capsule; Dietary supplement: Placebo (maltodextrin)

• Study Type: Interventional
• Enrollment (Estimated): 160
• Phase: Phase 2; Phase 3

Contacts and Locations

• Study Contact: Name: Maria Rodriguez-Palmero, PhD; Phone Number: +34 638679157; Email: rodriguezpalmero@ab-biotics.com
• Study Contact Backup: Name: Núria Gispets Parés; Phone Number: +34 607026612; Email: gispets@ab-biotics.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Females of ages 18-45 years (both values included) who are premenopausal.
• History of recurrent BV (at least 3 episodes in the last 12 months with at least one of them documented in the last 6 months).

• Positive Amsel's criteria (confirming active BV) determined by at least 3 out of the following 4 symptoms or signs:

  • Homogeneous, thin, yellowish-white/greyish white discharge that smoothly coats the vaginal walls.
  • Presence of the clue cells on microscopic examination (as assessed by wet mount test).
  • A fishy odor of vaginal discharge after adding 10% potassium hydroxide (KOH) solution to wet mount - also known as "whiff test".
  • Vaginal pH > 4.5
• Imbalance in vaginal pH (pH > 4.5).
• Participants with Body Mass Index (BMI) 18.5-32.0 kg/m2.
• Non-smokers.
• Participants able to comply with and perform the procedures requested by the protocol (including dietary restrictions, consumption of study treatments, blood and urine sample collection procedures and study visit schedule).
• Participants who are literate enough to understand the essence of study, are informed about the purpose of the study, and understand their rights.
• Participants able to give written informed consent and willingness to participate in the study and comply with its procedures.

Exclusion Criteria:

• Participants currently taking contraceptives and/or sexual hormones.
• Pregnant or breastfeeding.
• Menstrual period expected within the next 6 days of screening.
• Irregular cycle ("irregular" (e.g., less than 21 or more than 35 days consistently, or cycle variability more than 4 days month-to-month).
• Participants who have documented resistance to metronidazole.
• Participants diagnosed with any vaginal or urinary tract infection other than BV.
• Participants who have used other probiotics or antibiotics (vaginal, oral, parenteral) in the last 15 days.
• Participants using other vaginal products with bacteriostatic or bactericide activity (such as lactic acid gels, herbal extracts, dequalinum chloride, etc.).
• Participants with an intrauterine contraceptive device (IUCD/IUD) in situ at screening.
• Participants who have undergone total hysterectomy or any other surgery involving the female reproductive system.
• Women diagnosed with Sexually transmitted infections (STIs) or Human immunodeficiency virus (HIV) infection.
• Participants diagnosed with Polycystic ovary syndrome (PCOS) or other such diseases that further affect the hormonal homeostasis in women.
• Presence of uncontrolled diabetes mellitus (Indicated by Fasting Blood Glucose (FBG) more than or equal to 126 mg/dL. Fasting is defined as no caloric intake for at least 8 hours).
• Presence of uncontrolled hypertension (Defined as Systolic Blood Pressure (SBP) more than or equal to 140 mm Hg and/or Diastolic Blood Pressure (DBP) more than or equal to 90 mm Hg).
• Untreated previously diagnosed thyroid disorders.
• Participants who have a history of any significant neurological and psychiatric condition which may affect the participation and inference of the study's end points.
• Participation in other clinical trials in last 3 months prior to screening.

• Participants with substance abuse problems defined as:

  • High-risk drinking as defined by consumption of 4 or more alcohol containing beverages on any Day or 8 or more alcohol containing beverages per week for women.
• Participants who have any of the following clinically significant illness, i.e., Cardiovascular, endocrine system, immune system, respiratory system, hepatobiliary system, kidney and urinary system, neuropsychiatric, musculoskeletal, inflammatory, blood and tumors, chronic gastrointestinal diseases, etc.
• Any condition that could, in the opinion of the Investigator, preclude the participant's ability to successfully and safely complete the study or that may confound study outcomes.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Probiotic; Lactobacillus gasseri KABP064 in delayed-released (DR)-capsules. Strength: 1 x 10^9 CFU/capsule	Dietary supplement: Lactobacillus gasseri KABP®064 10e9 CFU/capsule; Phase 1: 15 days, 1 capsule/day post-randomization. Phase 2: 10 days per month for ~6 months, starting 6th day of menstruation, 1 capsule/day.
Placebo Comparator: Placebo; Placebo capsules filled with maltodextrine. Exact same appearance as active capsules.	Dietary supplement: Placebo (maltodextrin); Phase 1: 15 days, 1 capsule/day post-randomization. Phase 2: 10 days per month for ~6 months, starting 6th day of menstruation, 1 capsule/day.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the efficacy of Lactobacillus gasseri KABP®064 in preventing recurrence of BV infections, diagnosed using Amsel criteria, over a period of 6 months as compared to placebo.	Amsel criteria (≥3 out of 4 positive)	Day 6 to Day 180

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Analysis of BV recurrences diagnosed using Nugent score (≥ 7) (main secondary endpoint)	Compared to Placebo	Day 6 to Day 180
Analysis of BV recurrences diagnosed using both Amsel criteria (≥ 3 of 4 positive) and Nugent score (≥7)	Compared to placebo	Day 6 to Day 180
Time to first BV recurrence as per Amsel's criteria (≥3 of 4 positive) and/or Nugent Score (≥7)	Compared to Placebo	Day 6 to Day 180
Proportion of participants experiencing 2 or more, and 3 or more BV infections during the study period.	Compared to Placebo	Day 6 to Day 180
Percentage of patients receiving first-line or second-line SOC and duration (days).	Compared to Placebo	Day 6 to Day 180
Absolute difference in the duration of the SOC consumption (days).	Compared to Placebo	Day 6 to Day 180
Reducing the duration and severity of symptoms (itching, vaginal discharge, and odor) assessed by Visual Analogue Scale (VAS).	Compared to Placebo	Day 0, Day 6, Day 22, Day 90, Day 180, and at recurrence visits (if patients have a BV recurrence during the study time frame, they will ask for a "recurrence visit" to assess medication and some study parameters).
Percentage of patients with recovery of normal Nugent score (0-3).	Compared to Placebo	Day 6 to Day 22
Vaginal health by International Consultation on Incontinence Questionnaire - Vaginal symptoms (ICIQ-VS).	Compared to Placebo	Day 0, Day 6, Day 22, Day 90 and Day 180
Change in vaginal pH assessed by vaginal pH strip method.	Compared to Placebo	Day 0, Day 6, Day 22, Day 90, Day 180, and at recurrence visits (if patients have a BV recurrence during the study time frame, they will ask for a "recurrence visit" to assess medication and some study parameters).
Concentration of proinflammatory cytokines.	Compared to Placebo	Day 0, Day 22
Relative abundances of lactobacilli and common pathogens associated to BV assessed by using Next-Generation Sequencing (NGS).	Compared to Placebo	Day 0, Day 6, Day 22, Day 90, Day 180
Percentage of women with vaginal Community State Types (CSTs) associated to healthy vaginal microbiota.	Compared to Placebo	Day 0, Day 6, Day 22, Day 90, Day 180
Analysis of BV recurrences (including intermediate BV) as confirmed per Amsel criteria (≥ 3 of 4 positive) and Nugent score (score≥4) throughout the 6-month period.	Compared to Placebo	Day 6 to Day 180
Analysis of BV recurrences (including intermediate BV) as confirmed per Nugent score (score ≥4) throughout the 6-month period.	Compared to Placebo	Day 6 to Day 180

Collaborators and Investigators

• Sponsor: Kaneka Americas Holding Inc.
• Collaborators: Vedic Lifesciences Pvt. Ltd.; AB-Biotics

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): October 1, 2027

Study Registration Dates

• First Submitted: March 25, 2026
• First Submitted That Met QC Criteria: April 9, 2026
• First Posted (Actual): April 14, 2026

Study Record Updates

• Last Update Posted (Actual): April 14, 2026
• Last Update Submitted That Met QC Criteria: April 9, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Microbiome; Metronidazole; Recurrence; Bacterial Vaginosis
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Pathologic Processes; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Disease Attributes; Infections; Genital Diseases, Female; Bacterial Infections; Bacterial Infections and Mycoses; Vaginitis; Vaginal Diseases; Pathological Conditions, Signs and Symptoms; Recurrence; Vaginosis, Bacterial; maltodextrin
• Other Study ID Numbers: 241002/IP/BV

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No