NCT07846371 · Cambiotics ApS
Effect of a Dietary Supplement Versus Placebo on Serum PFAS Levels in Male Firefighters
(AFCRO202)
What this study is about
This study is designed to evaluate the effect of a probiotic dietary supplement containing Streptococcus salivarius on serum PFAS levels in male firefighters with documented occupational PFAS exposure, following twice-daily use over a 12-week period.
View original scientific description
This study is designed to evaluate the effect of a probiotic dietary supplement containing Streptococcus salivarius on serum PFAS levels in male firefighters with documented occupational PFAS exposure, following twice-daily use over a 12-week period.
Interventions
DIETARY_SUPPLEMENT
Streptococcus salivarius 46-SL1
One capsule (\~400 mg live probiotic) consumed twice daily with water, in the morning with breakfast and with the evening meal, for 84 days.
DIETARY_SUPPLEMENT
Placebo
Matching placebo capsule containing microcrystalline cellulose, magnesium stearate and silicon dioxide, consumed twice daily with water for 84 days.
Primary outcome measures
Change in serum linear perfluorooctane sulfonic acid (n-PFOS)
Time frame: Baseline (Day 0) to Day 84 of each intervention period
Change in serum n-PFOS concentration (ng/mL) from baseline to end of each 84-day intervention period, comparing the dietary supplement with placebo.
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
- Able to give written informed consent
- Male firefighter with previous career exposure to PFAS
- BMI between 18.5 and 35 kg/m²
- Serum PFOS level ≥5 ng/mL at screening
- Willing to consume the study product daily for the duration of the study
Exclusion criteria
- History of drug and/or alcohol abuse (\>15 standard drinks per week)
- Food allergy, intolerance or dietary restriction that, in the opinion of the investigator, would preclude consumption of the study product
- Blood donation within the past 3 months
- Current smoker of \>20 cigarettes per day, or former smoker with a history of ≥20 cigarettes per day who quit within 6 months prior to Visit 1
- Any significant acute or chronic health condition that would prevent participation, pose a risk, or confound interpretation of results, including: diagnosed gastrointestinal disorders (irritable bowel syndrome, inflammatory bowel disease, Crohn's disease, ulcerative colitis, coeliac disease, or other chronic diarrhoeal disorders); uncontrolled medical conditions; history of chronic kidney or liver disease; chronic inflammatory or autoimmune disease; history of gastrointestinal surgery; hospitalisation within the past 3 months
- Current or recent (past 12 weeks) use of medications affecting bile acid metabolism (e.g. bile acid sequestrants, fibrates) or antibiotics
- Current or recent (past 4 weeks) use of supplements affecting gut microbiota (prebiotics, probiotics, postbiotics, fibres, synbiotics), detoxification pathways (milk thistle, N-acetylcysteine, glutathione) or bile acid metabolism (e.g. psyllium husk)
- Current or recent (past 2 weeks) consumption of prohibited foods, including probiotic yoghurts
- Considered by the investigator unlikely to comply with study requirements
- Current participation in another clinical study, or insufficient time elapsed since a previous experimental study
Where
- Chicago, Illinois
Collaborators
Atlantia Food Clinical Trials
Related conditions & keywords
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 Oct 8, 2026 · Source of record for eligibility and locations