URTI - Viral Upper Respiratory Tract InfectionNCT07091955
Clinical Trial to Evaluate the Efficacy of a Probiotic Preparation in the Prevention of Upper Respiratory Tract Infections in Adults
A study testing Lacticaseibacillus rhamnosus CRL1505 in people with URTI - Viral Upper Respiratory Tract Infection and Prevention, run by Bioithas SL at 1 site in Spain.
Trial summary
Randomized, double-blind, placebo-controlled, parallel-group, clinical trial to assess the efficacy of the intake of a probiotic product composed of Lacticaseibacillus rhamnosus CRL1505 strain in reducing or preventing upper respiratory tract infections (URTIs) in a healthy adult population Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- URTI - Viral Upper Respiratory Tract Infection, Prevention
- What is being tested?
- Lacticaseibacillus rhamnosus CRL1505
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 140 participants
- Where
- 1 siteSpain
- Study dates
- 16 Oct 2023to 27 Feb 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Healthy men and women between 18 and 65 years.
- Signed Informed Consent to participate in the study
- BMI less than 35 kg/m2
Who cannot join
- Chronic pathological conditions such as chronic respiratory diseases (asthma, chronic bronchitis, chronic obstructive pulmonary disease etc), chronic heart diseases (chronic heart failure etc), chronic neurological diseases (Parkinson´s diseases, multiple esclerosis etc), chronic liver diseases, kidney liver diseases, gastrointestinal diseases, hematologic disorders etc, or other disease or condition that the researcher considers
- Metabolic disorders (diabetes, obesity with BMI greater than 35.1 kg/m2 etc).
- Congenital or acquired immune defects (including allergies).
- Immunocompromised individuals (HIV infection, chemotherapy, post-trasplant, chronic corticosteroid treatment etc).
- Presence of nasal ulcers/nasal polyps or other conditions that could cause nasal obstruction.
- Abuse of alcohol, tobacco or other drugs.
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- Pregnancy or lactation.
- Regular intake of products that could influence the study outcome (immune suppressants/immune stimulants including paramedication such as Echinacea, analgesics, antiinflammatories, antitussives/expectorants, influenza remedies, mouth or throat therapeutics, decongestants, antibiotics, antihistaminergic drugs, probiotics) within the last 4 weeks prior to the study start.
- Influenza vaccination in the last 6 monts.
Trial locations and contacts
1 site in 1 country.
Spain1 site
Universidad Católica San Antonio de Murcia (UCAM)
Murcia, Murcia, 30107
About this study
Official title: Randomized, Double-blind, Placebo-controlled Clinical Trial to Evaluate the Efficacy of a Probiotic Preparation in the Prevention of Upper Respiratory Tract Infections in a Healthy Adult Population
Randomized, double-blind, placebo-controlled, parallel-group, clinical trial to assess the efficacy of the intake of a probiotic product composed of Lacticaseibacillus rhamnosus CRL1505 strain in reducing or preventing upper respiratory tract infections (URTIs) in a healthy adult population
Read the detailed description
Randomized, double-blind, placebo-controlled, parallel-group, clinical trial. The study aims to demonstrate the efficacy of the intake of a probiotic product composed of Lacticaseibacillus rhamnosus CRL1505 strain in reducing or preventing upper respiratory tract infections in a healthy adult population.
The study will be focused on a healthy population, so the exclusion criteria will rule out individuals with major acute or chronic illnesses and an immunocompromised state. In addition, those subjects with a regular pharmacological treatment or consumption of food supplements that could influence the outcome of the study in the last 4 weeks prior to inclusión will be excluded. If patients could discontinue this treatment after a washout period and during the intervention period, they would be able to participate in the study. However, the usual medication that is considered not to influence the results of the study will be allowed. Subjects recently vaccinated against influenza will also be excluded, but as the study focuses on a healthy population, a priori vaccination is not recommended and there would be no problem in finding subjects with these characteristics because there is no contradiction.
In addition, subjects included will be asked not to modify their diet or physical activity during the study.
An important data that is not usually recorded in many studies is the use of medication to alleviate the symptoms of URTI, either non-prescription or prescribed by the physician. Only antibiotic medication to treat or prevent bacterial upper respiratory tract coinfections or complications is usually established as a variable (the use of antibiotics is established as a secondary variable in the present study). The investigators consider that it is very important to record the use of these treatments to evaluate if any study group is unbalanced in this regard and/or whether it is a confusion factor when interpreting the results. The investigators could consider the possibility of performing a post hoc analysis of this topic and present it in the final report if the results are interesting.
Similarly, it is important to collect baseline data related to the type of work or continuous contact with people with risk factors such as children or elderly to assess whether the groups are balanced. It will also be collected data about the number of URTIs in the study subjects since 3 months prior to inclusion.
The treatment period will be 12 weeks. There will then be a follow-up period (without treatment) of 4 weeks to evaluate the sustained effect of the probiotic product. The study will be structured in 3 face-to-face visits at week 0, 12 and 16.
For the evaluation of the efficacy variables, a diary would be provided to the study subject for a daily evaluation. Saliva collection kits for the determination of salivary IgA in the initial o final visits will also be provided.
The complete inclusion process will be carried out in October and November so that the study was located in the months of highest URTI incidence.
- Being tested
- Lacticaseibacillus rhamnosus CRL1505, Placebo Comparator
- Keywords
- upper respiratory tract infections, prevention, probiotics, microbiota, microbiome
- Medical subject headings
- Respiratory Tract Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lacticaseibacillus rhamnosus CRL1505Dietary supplement
Probiotic product containing Lacticaseibacillus rhamnosus CRL1505 formulated in a vegetable hydroxymethylpropyl-cellulose capsule of size 2
Placebo ComparatorDietary supplement
Placebo product containing cornstarch, in a vegetable hydroxymethylpropyl-cellulose capsule of size 2
| Study group | Role | What they receive |
|---|---|---|
| Lacticaseibacillus rhamnosus CRL1505 | Experimental | Probiotic product containing Lacticaseibacillus rhamnosus CRL1505 formulated in a vegetable hydroxymethylpropyl-cellulose capsule of size 2 Receives: Dietary Supplement: Lacticaseibacillus rhamnosus CRL1505 |
| Placebo | Placebo comparator | Placebo product containing cornstarch, in a vegetable hydroxymethylpropyl-cellulose capsule of size 2 Receives: Dietary Supplement: Placebo Comparator |
What is being measured
The primary outcome is the main question the study is designed to answer.
Patients who were diagnosed with at least 1, 2 or 3 URTIs
Difference in the proportion of patients who were diagnosed with at least 1, 2 or 3 URTIs during the intervention (12 weeks) and follow-up period (16 weeks) between the study groups
Measured: 16 weeks
Number of URTIs per patient
Difference in the mean number of URTIs per patient between the study groups during the intervention period (12 weeks) and follow-up period (16 weeks)
Measured: 16 weeks
Patients who were diagnosed of common cold and influenza
Difference in the proportion of patients who were diagnosed of common cold and influenza during the intervention (12 weeks) and follow-up period (16 weeks) between the study groups.
Measured: 16 weeks
Secondary outcomes (14)
Participants who presented URTI complications
Difference in the proportion of participants who presented URTI complications such as pneumonia, otitis media and acute sinusitis during intervention and follow-up periods between study groups
Measured: 16 weeks
Number of URTI complications
Difference in the number of URTI complications such as pneumonia, otitis media and acute sinusitis during intervention and follow-up periods between study groups
Measured: 16 weeks
Number of days until the occurrence of the first URTI episode
Mean number of days until the occurrence of the fist URTI episode during the 12 week intervention period
Measured: 12 weeks
Number of days with URTI episode per participant
Difference in the mean number of days with URTI episode per participant (days with URTI/number of participants) during the study (12 weeks treatment period and 16 weeks follow-up period)
Measured: 16 weeks
Duration of URTI episode
Difference in the mean duration of each episode of URTI (days with URTI/number of URTIs) during the study, including the treatment period (12 weeks) and the follo-up (16 weeks)
Measured: 16 weeks
URTI-Free Time Rate
Difference in the URTI-Free Time Rate, defined as the proportion of accumulated days where patients do not experience URTIs in relation to the total days of all study (intervention period of 12 weeks and follo up period of 16 weeks)
Measured: 16 weeks
Participants who presented gastrointestinal infections
Difference in the proportion of participants who presented gastrointestinal infections at the intervention and follow-up periods between study groups
Measured: 16 weeks
Number of gastrointestinal infections
Difference in the number of gastrointestinal infections at the intervention and follow-up periods between study groups
Measured: 16 weeks
Salivary IgA concentrations
Difference in mean salivary IgA concentrations during intervention period between study groups
Measured: 12 weeks
Participants using antibiotics
Difference in the proportion of participants using antibiotics during intervention and follow-up periods between study groups
Measured: 16 weeks
Number of days with antibiotics treatment
Difference in the days with antibiotics treatment during intervention and follow-up periods between study groups
Measured: 16 weeks
Participants using symptomatic treatment
Difference in the proportion of participants using symptomatic treatment during intervention and follow-up periods between study groups
Measured: 16 weeks
Number of days with symptomatic treatment during the study
Difference in the days with symptomatic treatment during intervention and follow-up periods between study groups
Measured: 16 weeks
"Common cold episode day" Wisconsin Upper Respiratory Symptom Survey - 21 item score (WURSS-21 score)
Difference in mean "common cold episode day" WURSS-21 score during intervention and follow-up periods between study groups.
The WURSS-21 score is a validated patient-reported outcome measure designed to assess the impact of upper respiratory tract infections (URTI), such as the common cold, on patients' daily lives.
Each item is rated on a Likert-type scale from 0 to 7.
0 = no symptoms / not at all
7 = very severe / very much
Measured: 16 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jul 2025
- Study start16 Oct 2023
- Primary completion27 Feb 2024
- Study completion27 Feb 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for URTI - Viral Upper Respiratory Tract InfectionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, double-blind, placebo-controlled with parallel assignment
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 140 participants (actual)
Sponsor and investigators
- Lead sponsor
- Bioithas SL
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Centro Sperimentale del Latte S.r.l.
- Responsible party
- Sponsor
- Investigators
- Valentina Taverniti, Microbes & Health R&D Leader, Study director, Centro Sperimentale del Latte S.r.l.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07091955
- Sponsor's protocol ID
- IRESP.PROB
- Status last verified
- Aug 2025
- First submitted
- 8 Jul 2025
- Last updated
- 22 Aug 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized, Double-blind, Placebo-controlled Clinical Trial to Evaluate the Efficacy of a Probiotic Preparation in the Prevention of Upper Respiratory Tract Infections in a Healthy Adult Population
- ClinicalTrials.gov ID
- NCT07091955
- Acronym / sponsor ID
- IRESP.PROB
- Keywords
- upper respiratory tract infections, prevention, probiotics, microbiota, microbiome
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 140 participants (actual)
- Lead sponsor
- Bioithas SLIndustry (pharma, biotech, devices)
- Collaborators
- Centro Sperimentale del Latte S.r.l.
- Study start
- 16 Oct 2023 (actual)
- Primary completion
- 27 Feb 2024 (actual)
- Study completion
- 27 Feb 2024 (actual)
- First posted
- 29 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Randomized, double-blind, placebo-controlled, parallel-group, clinical trial to assess the efficacy of the intake of a probiotic product composed of Lacticaseibacillus rhamnosus CRL1505 strain in reducing or preventing upper respiratory tract infections (URTIs) in a healthy adult population
Detailed description
Randomized, double-blind, placebo-controlled, parallel-group, clinical trial. The study aims to demonstrate the efficacy of the intake of a probiotic product composed of Lacticaseibacillus rhamnosus CRL1505 strain in reducing or preventing upper respiratory tract infections in a healthy adult population.
The study will be focused on a healthy population, so the exclusion criteria will rule out individuals with major acute or chronic illnesses and an immunocompromised state. In addition, those subjects with a regular pharmacological treatment or consumption of food supplements that could influence the outcome of the study in the last 4 weeks prior to inclusión will be excluded. If patients could discontinue this treatment after a washout period and during the intervention period, they would be able to participate in the study. However, the usual medication that is considered not to influence the results of the study will be allowed. Subjects recently vaccinated against influenza will also be excluded, but as the study focuses on a healthy population, a priori vaccination is not recommended and there would be no problem in finding subjects with these characteristics because there is no contradiction.
In addition, subjects included will be asked not to modify their diet or physical activity during the study.
An important data that is not usually recorded in many studies is the use of medication to alleviate the symptoms of URTI, either non-prescription or prescribed by the physician. Only antibiotic medication to treat or prevent bacterial upper respiratory tract coinfections or complications is usually established as a variable (the use of antibiotics is established as a secondary variable in the present study). The investigators consider that it is very important to record the use of these treatments to evaluate if any study group is unbalanced in this regard and/or whether it is a confusion factor when interpreting the results. The investigators could consider the possibility of performing a post hoc analysis of this topic and present it in the final report if the results are interesting.
Similarly, it is important to collect baseline data related to the type of work or continuous contact with people with risk factors such as children or elderly to assess whether the groups are balanced. It will also be collected data about the number of URTIs in the study subjects since 3 months prior to inclusion.
The treatment period will be 12 weeks. There will then be a follow-up period (without treatment) of 4 weeks to evaluate the sustained effect of the probiotic product. The study will be structured in 3 face-to-face visits at week 0, 12 and 16.
For the evaluation of the efficacy variables, a diary would be provided to the study subject for a daily evaluation. Saliva collection kits for the determination of salivary IgA in the initial o final visits will also be provided.
The complete inclusion process will be carried out in October and November so that the study was located in the months of highest URTI incidence.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized, double-blind, placebo-controlled with parallel assignment
| Arm | Type | Receives |
|---|---|---|
| Lacticaseibacillus rhamnosus CRL1505 | Experimental | Dietary Supplement: Lacticaseibacillus rhamnosus CRL1505Probiotic product containing Lacticaseibacillus rhamnosus CRL1505 formulated in a vegetable hydroxymethylpropyl-cellulose capsule of size 2 |
| Placebo | Placebo comparator | Dietary Supplement: Placebo ComparatorPlacebo product containing cornstarch, in a vegetable hydroxymethylpropyl-cellulose capsule of size 2 |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Healthy men and women between 18 and 65 years.
- Signed Informed Consent to participate in the study
- BMI less than 35 kg/m2
Key exclusion criteria (9 listed)
- Chronic pathological conditions such as chronic respiratory diseases (asthma, chronic bronchitis, chronic obstructive pulmonary disease etc), chronic heart diseases (chronic heart failure etc), chronic neurological diseases (Parkinson´s diseases, multiple esclerosis etc), chronic liver diseases, kidney liver diseases, gastrointestinal diseases, hematologic disorders etc, or other disease or condition that the researcher considers
- Metabolic disorders (diabetes, obesity with BMI greater than 35.1 kg/m2 etc).
- Congenital or acquired immune defects (including allergies).
- Immunocompromised individuals (HIV infection, chemotherapy, post-trasplant, chronic corticosteroid treatment etc).
- Presence of nasal ulcers/nasal polyps or other conditions that could cause nasal obstruction.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Lacticaseibacillus rhamnosus CRL1505Probiotic product containing Lacticaseibacillus rhamnosus CRL1505 formulated in a vegetable hydroxymethylpropyl-cellulose capsule of size 2 | Dietary supplement | Lacticaseibacillus rhamnosus CRL1505 |
| Placebo ComparatorPlacebo product containing cornstarch, in a vegetable hydroxymethylpropyl-cellulose capsule of size 2 | Dietary supplement | Placebo |
Primary outcome
Patients who were diagnosed with at least 1, 2 or 3 URTIs
Time frame: 16 weeks
Difference in the proportion of patients who were diagnosed with at least 1, 2 or 3 URTIs during the intervention (12 weeks) and follow-up period (16 weeks) between the study groups
Number of URTIs per patient
Time frame: 16 weeks
Difference in the mean number of URTIs per patient between the study groups during the intervention period (12 weeks) and follow-up period (16 weeks)
Patients who were diagnosed of common cold and influenza
Time frame: 16 weeks
Difference in the proportion of patients who were diagnosed of common cold and influenza during the intervention (12 weeks) and follow-up period (16 weeks) between the study groups.
14 secondary outcomes
Participants who presented URTI complications
Time frame: 16 weeks
Number of URTI complications
Time frame: 16 weeks
Number of days until the occurrence of the first URTI episode
Time frame: 12 weeks
Number of days with URTI episode per participant
Time frame: 16 weeks
Duration of URTI episode
Time frame: 16 weeks
URTI-Free Time Rate
Time frame: 16 weeks
Participants who presented gastrointestinal infections
Time frame: 16 weeks
Number of gastrointestinal infections
Time frame: 16 weeks
Salivary IgA concentrations
Time frame: 12 weeks
Participants using antibiotics
Time frame: 16 weeks
Number of days with antibiotics treatment
Time frame: 16 weeks
Participants using symptomatic treatment
Time frame: 16 weeks
Number of days with symptomatic treatment during the study
Time frame: 16 weeks
"Common cold episode day" Wisconsin Upper Respiratory Symptom Survey - 21 item score (WURSS-21 score)
Time frame: 16 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Aug 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Valentina Taverniti, Microbes & Health R&D Leader study director
Centro Sperimentale del Latte S.r.l.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Lacticaseibacillus rhamnosus CRL1505 in people with URTI - Viral Upper Respiratory Tract Infection and Prevention, run by Bioithas SL at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Patients who were diagnosed with at least 1, 2 or 3 URTIs (time frame: 16 weeks). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Aug 2025.