Probiotic power: could a daily capsule keep athletes in the game?
NCT ID NCT07782983
First seen Aug 24, 2026 · Last updated Aug 25, 2026 · Updated 1 time
Summary
This pilot study tests whether a daily multi-strain probiotic supplement can improve mucosal immunity and reduce upper respiratory symptoms in trained team-sport athletes. Over 28 days, participants take either a probiotic capsule or a placebo, with saliva samples collected to measure immune markers. The goal is to see if this approach is feasible for a larger trial that could help athletes stay healthy during training and competition.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Multi-strain probiotic supplement (Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Bifidobacterium lactis Bl-04, Bifidobacterium lactis Bi-07, Bifidobacterium bifidum Bb-02)
- What this could lead to
- If this pilot shows promise, it could lead to a larger trial testing whether daily probiotics help athletes fight off colds and other upper respiratory infections.
- What could go wrong
- This is a small pilot study focused on feasibility, not effectiveness. Results may not be conclusive, and individual responses to probiotics can vary.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Not a phased trial
Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.
- Participants
-
15 people
The number who actually took part.
- Started
-
May 2025
- Finished
-
Dec 2025
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
18 to 40 years
- Sex
-
Anyone
- Healthy volunteers
-
Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Male trained athletes aged 18-40 years. * Regularly participating in structured training and/or competitive sport. * Apparently healthy at enrolment, with no acute illness or injury that would prevent completion of the exercise testing protocol. * Able to complete high-intensity treadmill exercise testing. * Willing to consume the assigned supplement daily for the full intervention period. * Willing to avoid probiotic supplements, prebiotic supplements, and other new immune- or gut-health-related supplements during the study period. * Willing and able to provide saliva samples and complete daily upper respiratory symptom monitoring. * Able to provide written informed consent. Exclusion Criteria: * Current acute respiratory, gastrointestinal, or systemic illness at enrolment. * Use of antibiotics within the previous 4 weeks. * Regular use of probiotic or prebiotic supplements before enrolment, unless willing to stop before and during the study period. * Use of medication or supplements likely to affect immune, inflammatory, gastrointestinal, or salivary biomarker outcomes. * Known chronic gastrointestinal disease, immune disorder, metabolic disease, cardiovascular disease, or other medical condition that could affect study outcomes or exercise safety. * Known allergy or intolerance to any ingredient in the probiotic or placebo capsule. * Current smoker or regular nicotine user. * Any musculoskeletal injury or health condition limiting maximal or high-intensity treadmill exercise. * Participation in another intervention study during the study period. * Inability or unwillingness to comply with the study procedures.
Get updates
Get notified about this study
Sign up to get updates when this study changes or when new studies for Mucosal immunity are added.
By submitting, you agree to our Terms of use
Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
Ulster University Belfast Campus, Human Physiology Laboratory, Room BC-04-409
Belfast, Northern Ireland, BT15 1ED, United Kingdom
More trials for these conditions
Other studies related to the condition(s) this trial covers.