Effect of a Short-term Multi-strain Probiotic Supplementation in Endurance Athletes

NCT07252778 | Recruiting Phase 2

• 1 other identifier: ZDS2025_0002
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this project is to evaluate and identify the effect of a short-term 2-week multi-strain probiotic (MPRO) supplementation on the exercise-associated gastrointestinal (GI) symptoms and perturbations in high level female athletes of the Polish national team during strictly controlled conditions of a training camp, based on recommendations for best practices for probiotic (PRO) research in athletes and assessment of EX-associated GI perturbations.

Conditions

Sports Nutrition; Biochemical Markers; Exercise Performance; Aerobic Capacity; Supplementation

Keywords

Probiotics; Gastro-intestinal markers; Microbiota; Rowing; Females

Outcome Measures

Primary Outcomes (7)

• Changes in gastrointestinal integrity and inflammation markers (I-FABP, claudin-3, zonulin, LPS, scd-14, LBP, ocludin, lipocalin-2, DAO) (ng/mL) in blood after MPRO supplementation and PLA treatment

  Assessment of the gastrointestinal integrity markers (I-FABP, claudin-3, zonulin, LPS, scd-14, LBP, ocludin, lipocalin-2, DAO) (ng/mL) in blood at three time-points (resting \[REST\]; 3 min \[POST-EX\] and 60 min after completion of the test exercise \[REC\]) will be carried out at four main visits to the laboratory (T1-T4; before/after supplementation with MPRO and PLA).

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in gastrointestinal integrity and inflammation markers (zonulin, ocludin, lipocalin-2) (ng/mL) in stool after MPRO supplementation and PLA treatment

  Assessment of the gastrointestinal integrity markers (zonulin, ocludin, lipocalin-2) (ng/mL) in stool at rest will be carried out at four main visits to the laboratory (T1-T4; before/after supplementation with MPRO and PLA).

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in gastrointestinal integrity and inflammation markers (calprotectin, lactoferrin) (μg/g) in stool after MPRO supplementation and PLA treatment

  Assessment of the gastrointestinal integrity markers (calprotectin, lactoferrin) (μg/g) in stool at rest will be carried out at four main visits to the laboratory (T1-T4; before/after supplementation with MPRO and PLA).

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in gastrointestinal integrity and inflammation markers (α-1 antitripsin) (mg/g) in stool after MPRO supplementation and PLA treatment

  Assessment of the gastrointestinal integrity markers (α-1 antitripsin) (mg/g) in stool at rest will be carried out at four main visits to the laboratory (T1-T4; before/after supplementation with MPRO and PLA).

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in gut microbiota phylogenetic diversity (Faith's phylogenetic diversity index) after MPRO supplementation and PLA treatment

  Assessment of phylogenetic α-diversity of the gut microbiome assessed from stool 16S rRNA gene sequencing; computed as Faith's Phylogenetic Diversity (sum of branch lengths on the phylogenetic tree corresponding to observed taxa) at rest will be carried out at four main visits to the laboratory (T1-T4; before/after supplementation with MPRO and PLA).

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in gut microbiota species diversity (Shannon diversity index) after MPRO supplementation and PLA treatment

  Assessment of species (taxonomic) α-diversity of the gut microbiome assessed from stool 16S rRNA gene sequencing; computed using the Shannon diversity index (accounts for richness and evenness) at rest will be carried out at four main visits to the laboratory (T1-T4; before/after supplementation with MPRO and PLA).

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in gut microbiota species richness (number of observed species (OTUs)) after MPRO supplementation and PLA treatment

  Assessment of species richness of the gut microbiome assessed from stool 16S rRNA gene sequencing; reported as the number of observed operational taxonomic units (Observed OTUs) at rest will be carried out at four main visits to the laboratory (T1-T4; before/after supplementation with MPRO and PLA).

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

Secondary Outcomes (7)

• Changes in blood cytokines (IL-1β/1ra/6/8/10/17, TNF-α) (pg/mL) after MPRO supplementation and PLA treatment

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in stress marker (cortisol) (ng/ml) in blood and saliva after MPRO supplementation and PLA treatment

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in saliva SIgA concentration (μg/mL) after MPRO supplementation and PLA treatment

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in gastrointestinal symptoms incidence and severity (points) after MPRO supplementation and PLA treatment

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in psychological stress and mood (points) after MPRO supplementation and PLA treatment

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

Other Outcomes (26)

• Changes in the aerobic fitness and exercise performance test results (aerobic capacity measured by maximum workload at exhaustion in Watts) after MPRO supplementation and PLA treatment IRT performance

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in the aerobic fitness and exercise performance test results (aerobic capacity measured by maximal oxygen uptake in mL/min/kg) after MPRO supplementation and PLA treatment IRT performance

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

• Changes in heart rate (bpm) during aerobic fitness and exercise performance test after MPRO supplementation and PLA treatment

  Baseline (before MPRO supplementation) and after 2 weeks of MPRO supplementation; baseline (before PLA supplementation) and after 2 weeks of PLA supplementation.

Study Arms (2)

MPRO supplementation

EXPERIMENTAL

The experimental procedure for each participant in this group will include a 2-week period of MPRO supplementation. The entire study protocol will include familiarization and 4 main study visits (T1-T4; before/after supplementation). Enrolled volunteers will be randomly assigned to the treatment order with specific codes by an impartial biostatistician. Each study visit will consist of anthropometric indices and body composition evaluation, three saliva and blood samplings (resting; 3 min and 60 min after exercise) and exercise performance evaluation. Additionally, all participants will donate their stool samples into specially prepared two empty tubes. Samples will be collected on the same days as saliva/blood samples, early in the morning. Moreover, during each study visit, participants will complete a specific, validated GI symptoms questionnaire and specific and validated stress and mood questionnaires to assess their stress and mood before and after MPRO supplementation.

Dietary Supplement: MPRO supplementation

PLA treatment

PLACEBO COMPARATOR

The experimental procedure for each participant in this group will include a 2-week period of placebo supplementation. The entire study protocol will include familiarization and 4 main study visits (T1-T4; before/after supplementation). Enrolled volunteers will be randomly assigned to the treatment order with specific codes by an impartial biostatistician. Each study visit will consist of anthropometric indices and body composition evaluation, three saliva and blood samplings (resting; 3 min and 60 min after exercise) and exercise performance evaluation. Additionally, all participants will donate their stool samples into specially prepared two empty tubes. Samples will be collected on the same days as saliva/blood samples, early in the morning. Moreover, during each study visit, participants will complete a specific, validated GI symptoms questionnaire and specific and validated stress and mood questionnaires to assess their stress and mood before and after placebo supplementation.

Dietary Supplement: Placebo treatment

Interventions

MPRO supplementation DIETARY_SUPPLEMENT

In the experimental procedure each athlete will be supplemented with a certificated, commercially available MPRO supplement SANPROBI® Barrier (Bifidobacterium lactis W52, Lactobacillus brevis W63, Lactobacillus casei W56, Lactococcus lactis W19, Lactococcus lactis W58, Lactobacillus acidophilus W37, Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Lactobacillus salivarius W24). The supplement will be provided in the capsule form and will be taken twice a day \[4 capsules of MPRO/day (2×10to9 CFU/g, 500 milions CFU/capsule) in two servings/day (2x2 capsules\].

MPRO supplementation

Placebo treatment DIETARY_SUPPLEMENT

In the control procedure each athlete will be supplemented with a placebo (PLA). The PLA group will receive corn starch mixed with maltodextrins. The PLA will be provided in the capsule form and will be taken twice a day (2x2 capsules/day).

PLA treatment

Eligibility Criteria

• Age: 16 Years - 50 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• belonging to the national rowing team;
• training experience ≥5 years;
• a currently issued medical certificate confirming
• good health and capacity to practice sports;
• good health without chronic health disorders;
• written informed consent to participate.

You may not qualify if:

• injury, any health contraindication or failure to perform exercise procedures;
• gastrointestinal infections, diseases, disorders;
• past history of gastrointestinal surgery, and
• other self-reported gastrointestinal issues;
• reporting symptoms of infection or taking any medication (e.g. antibiotics) for 4 weeks before the study protocol;
• current supplementation of prebiotics,
• probiotics, synbiotics (last 4 weeks);
• current intake of pharmaceutical agents (e.g., nonsteroidal anti-inflammatory drugs, laxatives, antidiarrhea agents, antacids, and/or antiemetics) (last 4 weeks);
• failure to follow the study protocol;
• declared general feeling of being unwell;
• pregnancy or current pregnancy planning.

Sponsors & Collaborators

• Krzysztof Durkalec-Michalski: lead
• Institute of Human Genetics, Polish Academy of Sciences: collaborator

Study Sites (1)

Department of Sports Dietetics, Poznan University of Physical Education Poznań

Poznan, Wielkopolska, 61-871, Poland

RECRUITING

Study Officials

• Krzysztof Durkalec-Michalski, PhD

  Department of Sports Dietetics, Poznan University of Physical Education Poznań

  STUDY CHAIR

Central Study Contacts

Natalia Główka, PhD

CONTACT

+48 691 756 944; glowka@awf.poznan.pl

Krzysztof Durkalec-Michalski, PhD

CONTACT

durkalec-michalski@awf.poznan.pl

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Prof.

Study Record Dates

• First Submitted: September 27, 2025
• First Posted: November 28, 2025
• Study Start: November 20, 2025
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 30, 2027
• Last Updated: November 28, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will share

Locations

PL (1)