The Effects of Postbiotic Supplementation in Female Athletes
The Effect of Daily Supplementation With Humiome® Post LB on Gastrointestinal Symptoms in Female Athletes. A Double-blinded Randomised Controlled Trial.
Liverpool John Moores University
100 participants
May 5, 2026
INTERVENTIONAL
Conditions
Summary
The goal of this clinical trial is to learn if a postbiotic supplement can reduce stomach and gut symptoms in physically active women. The main questions it aims to answer are: Does the supplement reduce gut symptoms during the menstrual cycle? Does it improve symptoms related to exercise? Researchers will compare the postbiotic supplement to a placebo (a look-alike capsule that contains no active ingredient) to see if the supplement works. Participants will be physically active, premenopausal female athletes. Participants will: Take either the postbiotic supplement or a placebo each day for two menstrual cycles Track their menstrual cycle and training Report gut symptoms using regular questionnaires Provide stool samples to assess gut health This study will help researchers understand whether postbiotic supplements can improve gut health and reduce symptoms that may affect training and performance in female athletes.
Eligibility
Inclusion Criteria11
- Female, cisgender, premenopausal.
- Minimum age 18 years.
- Regular, natural menstrual cycle (21-35 days in duration), with 9 or more consecutive periods per year, if possible documented with tracker apps, calendars, or other tools
- Ability to give informed consent.
- Body mass index (BMI) ≥ 18.5 and < 24.9 kg/m²
- Agreeing to maintain lifestyle habits during the study (same dietary and physical activity habits)
- Having a smartphone and a history of consistent tracking of training and health records via apps.
- Having regular GI issues during exercise, and during menstruation. During pre-screening, this will be assessed with a shortened GSRS questionnaire, where participants need to have had, in the month preceding pre-screening, the equivalent of at least a score of 2 in a GSRS focus area (diarrhoea, pain, indigestion).
- No relevant self-reported abnormalities from medical history.
- Trained athlete (trains at least 3 times per week for more than 1 hour per day and who has been involved in endurance training for at least 2 years in alignment with previous research (Pfeiffer et al., 2010). This will be evaluated by assessing training records (Strava or similar applications, certificates of attendance at athletic events, club membership, etc.).
- Access to a health-care provider, who can be contacted by the CRO, and who reside in areas with available emergency health services.
Exclusion Criteria13
- Individuals who are pregnant, lactating, or plan to become pregnant before study end.
- Individuals with secondary amenorrhea.
- Individuals who use hormonal contraceptives during the last 6 months before (and during) the trial.
- Individuals who are currently participating in another clinical trial or have participated in a trial within the last two months prior to enrolment.
- Tobacco smokers and vapers.
- Individuals with acute illnesses.
- Individuals with a current musculoskeletal injury or one within the last month.
- Individuals taking probiotic supplements or have taken probiotics two weeks prior to enrolment.
- Individuals controlling chronic diseases with treatments known to alter the intestinal microbiome or to alter GI symptoms, such as certain pain killers, antacids, proton pump inhibitors, anti-diarrhoeal medication or supplements, and laxatives.
- Individuals having received antibiotics treatments within three months of trial start.
- Individuals having planned major changes in lifestyle (i.e. diet, weight loss program, exercise level, travelling) during the duration of the study.
- Individuals who have hypersensitivity/allergy to any of the components of the test product.
- Individuals who have planned major elective surgery during the study period.
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Interventions
Postbiotic supplement (Humiome® Post LB) administered as two oral capsules daily, providing 340 mg of postbiotic per day. The supplement contains heat-inactivated microbial strains and fermentation products. Participants will take the supplement daily for two consecutive menstrual cycles following a one-cycle placebo run-in phase.
Placebo capsules containing microcrystalline cellulose, matched in appearance to the postbiotic supplement. Participants will take two capsules daily during a one-cycle placebo run-in phase and, if randomized to the placebo group, continue for two additional menstrual cycles.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT07580118