Fermented Milk Drink With Lacticaseibacillus Paracasei Strain Shirota Helps Triathletes With Cold-Like Symptoms Before and After a Race

NCT ID: NCT06970964

Last Updated: 2026-01-15

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

80 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-08-13

Study Completion Date

2025-11-05

Brief Summary

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This study aims to evaluate whether a fermented milk drink containing the probiotic strain Lacticaseibacillus paracasei strain Shirota (LCS), commonly found in Yakult®, can help reduce upper respiratory symptoms in triathletes before and after competition.

Athletes often experience cold-like symptoms due to physical stress, intense training, and immune system challenges. The study investigates whether daily consumption of this probiotic drink can help improve immune response and reduce the incidence or severity of symptoms such as sore throat, nasal congestion, or coughing.

This is a randomized, double-blind, placebo-controlled, parallel-group study involving healthy adult triathletes. Participants will be randomly assigned to receive either the probiotic drink or a placebo for a specific period before and after a triathlon event. Symptoms and health markers will be tracked through questionnaires and biological samples.

The goal is to explore whether probiotic supplementation can provide practical, non-pharmacological support for athletes' immune health and well-being during intense physical activity.

Detailed Description

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Background:

Endurance athletes are frequently exposed to high physical stress, which may lead to temporary immune suppression and increased susceptibility to upper respiratory tract infections (URTIs). Previous studies suggest that probiotics may play a role in supporting the immune system.

Objective:

To assess the efficacy of a fermented milk drink containing Lacticaseibacillus paracasei strain Shirota (LCS) in reducing upper airway symptoms in triathletes before and after a competitive event.

Study Design:

This is a multi-center, double-blind, randomized, placebo-controlled, parallel-group study. Eligible participants will be healthy adult triathletes preparing for a scheduled race. They will be randomized to consume either the probiotic drink or a placebo daily, starting several weeks before the race and continuing for a defined recovery period afterward.

Primary Outcome:

-Salivary IgA Concentration The primary outcome is the change in salivary immunoglobulin A (IgA) concentration before and after the competition, assessed at five time points. This measure will reflect mucosal immune function and the potential modulatory effect of daily intake of fermented milk containing Lacticaseibacillus paracasei strain Shirota.

Secondary Outcomes:

* Systemic Immune and Inflammatory Response Blood samples will be analyzed for markers of systemic immune activation and inflammation (e.g., cytokines), collected at five time points to evaluate the broader immunomodulatory effects of the probiotic intervention.
* Upper Airway Symptoms Incidence, severity, and duration of upper airway symptoms (e.g., sore throat, cough, nasal congestion) will be assessed using the Wisconsin Upper Respiratory Symptom Survey-21 (WURSS-21). Higher scores indicate more severe symptoms and a greater impact on daily functioning.
* Mood State Mood state changes will be evaluated using the Brunel Mood Scale (BRUMS) across six subscales. Total Mood Disturbance (TMD) scores will reflect the psychological response to training and competition. Higher scores indicate worse mood states.

Conditions

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Respiratory Tract Infections (RTI) Mucosal Immunity Systemic Inflammation Depressive Disorder Exercise-Induced Immunosuppression Athletic Performance Upper Respiratory Tract Symptoms Mental Health Cytokine Response Probiotic Therapy

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Participants will be randomly assigned to one of two parallel groups: one receiving fermented milk containing Lacticaseibacillus paracasei strain Shirota and the other receiving placebo (non-fermented milk).
Primary Study Purpose

PREVENTION

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors
This is a double-blind study. Participants, care providers, investigators, and outcomes assessors will be blinded to group assignments to prevent bias.

Study Groups

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Probiotic

Participants will receive one bottle per day of fermented milk containing 40 billion colony-forming units of Lacticaseibacillus paracasei strain Shirota (LcS) for 44 days.Intervention:

Type: Dietary Supplement Name: Lacticaseibacillus paracasei strain Shirota Description: Daily intake of fermented milk containing 40 billion CFU of LcS.

Group Type EXPERIMENTAL

Intervention Name: Fermented milk containing Lacticaseibacillus paracasei strain Shirota. Intervention Name: Non-fermented milk (placebo)

Intervention Type DIETARY_SUPPLEMENT

Participants will ingest 80 mL per day of fermented milk containing 40 billion colony-forming units (CFU) of Lacticaseibacillus paracasei strain Shirota (LcS), starting 30 days before a triathlon competition and continuing until 14 days post-race. The fermented milk is stored refrigerated and consumed once daily.

Placebo Group

Name: Non-fermented milk Description: Daily intake of placebo (non-fermented milk) matched in appearance and taste to the probiotic.

Group Type PLACEBO_COMPARATOR

Non-fermented milk (placebo)

Intervention Type DIETARY_SUPPLEMENT

Participants will ingest 80 mL per day of non-fermented milk identical in taste, appearance, and packaging to the probiotic drink, but without Lacticaseibacillus paracasei strain Shirota. Administration follows the same schedule as the probiotic group.

Interventions

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Intervention Name: Fermented milk containing Lacticaseibacillus paracasei strain Shirota. Intervention Name: Non-fermented milk (placebo)

Participants will ingest 80 mL per day of fermented milk containing 40 billion colony-forming units (CFU) of Lacticaseibacillus paracasei strain Shirota (LcS), starting 30 days before a triathlon competition and continuing until 14 days post-race. The fermented milk is stored refrigerated and consumed once daily.

Intervention Type DIETARY_SUPPLEMENT

Non-fermented milk (placebo)

Participants will ingest 80 mL per day of non-fermented milk identical in taste, appearance, and packaging to the probiotic drink, but without Lacticaseibacillus paracasei strain Shirota. Administration follows the same schedule as the probiotic group.

Intervention Type DIETARY_SUPPLEMENT

Other Intervention Names

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LcS Lacticaseibacillus casei Shirota Probiotic milk drink Placebo milk

Eligibility Criteria

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Inclusion Criteria

* Aged between 25 and 45 years.
* Amateur triathletes with regular endurance training and prior competition experience.
* In good general health, with no history of chronic diseases or conditions affecting immune or inflammatory responses.
* Willing and able to comply with all study procedures, including sample collections and completion of validated questionnaires at five time points.
* Agree to consume a daily dose of fermented milk containing Lacticaseibacillus paracasei strain Shirota (LcS) or placebo from 30 days before until 14 days after the competition.
* No use of probiotics, antibiotics, or immunomodulatory supplements in the 30 days prior to enrollment

Exclusion Criteria

* Known allergy or intolerance to dairy products, including lactose.
* Use of probiotics or antibiotics within 30 days prior to enrollment.
* Current use of any pharmacological treatment.
* History of chronic rhinopathy.
* Diagnosis of autoimmune disease.
* History of recurrent infections not involving the upper airway.
* Presence of major medical conditions or chronic diseases, including but not limited to respiratory or gastrointestinal disorders.
* Incomplete or missing data necessary for determining eligibility or for study outcomes.
Minimum Eligible Age

25 Years

Maximum Eligible Age

45 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Federal University of São Paulo

OTHER

Sponsor Role lead

Responsible Party

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Jonatas Bussador do Amaral

Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Jonatas B do Amaral, PHD

Role: PRINCIPAL_INVESTIGATOR

Federal University of São Paulo

André Luis L Bachi, PHD

Role: STUDY_CHAIR

Santo Amaro University

Cesar Miguel M dos Santos, PHD

Role: STUDY_CHAIR

Enau College

Mauro W Vaisberg, PHD

Role: STUDY_CHAIR

Federal University of São Paulo

Locations

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Federal University of Sao Paulo

São Paulo, São Paulo, Brazil

Site Status

Countries

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Brazil

References

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Vaisberg M, Paixao V, Almeida EB, Santos JMB, Foster R, Rossi M, Pithon-Curi TC, Gorjao R, Momesso CM, Andrade MS, Araujo JR, Garcia MC, Cohen M, Perez EC, Santos-Dias A, Vieira RP, Bachi ALL. Daily Intake of Fermented Milk Containing Lactobacillus casei Shirota (Lcs) Modulates Systemic and Upper Airways Immune/Inflammatory Responses in Marathon Runners. Nutrients. 2019 Jul 22;11(7):1678. doi: 10.3390/nu11071678.

Reference Type BACKGROUND
PMID: 31336570 (View on PubMed)

Provided Documents

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Document Type: Study Protocol and Statistical Analysis Plan

View Document

Related Links

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https://ppg.unifesp.br/otorrino/institucional/laboratorio-de-pesquisa-em-otorrinolaringologia-orl-lab

ORL Lab -Official website of the laboratory where the activities will be carried out at the Federal University of Sao Paulo-Brazil

Other Identifiers

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7.349.261

Identifier Type: -

Identifier Source: org_study_id

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