Effects of Probiotics on Respiratory Tract Infections in Children: A Randomized, Placebo-Controlled Interventional Study

NCT07498127 | Enrolling By Invitation Phase 2

• 1 other identifier: 2025-225-(1)
• Study Type: interventional
• Target: 120
• Locations: 2 countries
• Sites: 2

Brief Summary

This study is a 14-day, randomized, double-blind, placebo-controlled trial involving children aged 3 months to 6 years who meet clinical diagnostic criteria for mild to moderate upper respiratory tract infection (URTI). Participants are randomized to receive either a mixed probiotic preparation (Lactobacillus rhamnosus CRL1505 and Bifidobacterium breve M-16V) or a placebo. The primary clinical outcome assessed is the duration and severity of respiratory symptoms. Secondary outcomes include changes in gut microbiota composition, intestinal immune markers, and quality of life. To investigate potential mechanisms, fecal samples are collected before and after intervention for metagenomic sequencing to analyze microbial diversity and composition, alongside immunological assessments such as sIgA and calprotectin.

Conditions

URTI

Keywords

URTI; probiotic; children

Outcome Measures

Primary Outcomes (1)

• Respiratory symptoms in children upon administration of probiotic or placebo as assessed via clinical questionnaire

  Differences in severity of respiratory symptoms in children upon administration of probiotic or placebo, assessed using a hospital-based clinical questionnaire scored on a 5-point ordinal scale (0 = no symptoms to 4 = severe symptoms), with lower scores indicating better respiratory status.

  Day-0, Day-14

Secondary Outcomes (3)

• Quality of life in children upon administration of probiotic or placebo via clinical questionnaire

  Day-0, Day-14

• Microbiota profiles of fecal samples in young children upon administration of probiotic or placebo as assessed via metagenomic sequencing

  Day-0, Day-14

• Intestinal immune markers from fecal samples in young children upon administration of probiotic or placebo via use of Enzyme-Linked Immunosorbent Assay (ELISA)

  Day-0, Day-14

Study Arms (2)

Probiotic

EXPERIMENTAL

Daily 6-drops of 1 × 10\^10 CFU containing Lactobacillus rhamnosus CRL1505 and Bifidobacterium breve M-16V in MCT oil

Dietary Supplement: Probiotic

Placebo

PLACEBO COMPARATOR

Daily 6-drops of MCT oil containing non-GMO cord starch

Dietary Supplement: Placebo Control

Interventions

Probiotic DIETARY_SUPPLEMENT

Daily 6-drops of 1 × 10\^10 CFU containing Lactobacillus rhamnosus CRL1505 and Bifidobacterium breve M-16V in MCT oil

Probiotic

Placebo Control DIETARY_SUPPLEMENT

Daily 6-drops of MCT oil containing non-GMO corn starch

Placebo

Eligibility Criteria

• Age: 3 Months - 6 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Children aged 3 months to 6 years, regardless of sex.
• Meet the clinical diagnostic criteria for upper respiratory tract infection, including but not limited to cough, rhinorrhea, nasal congestion, sore throat, and fever.
• Assessed by a clinician as having mild or moderate URTI, not requiring antibiotics or other systemic prescription medications, and suitable for observation and/or symptomatic management.
• Willing to discontinue other probiotics or supplements during the study period, except for the study product provided by the investigators.
• Agree to complete questionnaires and provide fecal biological samples during the study period.
• The child's parent(s) or legal guardian(s) are fully informed about the trial and voluntarily sign the written informed consent form before any study procedures begin.

You may not qualify if:

• Severe URTI as judged by the clinician, or symptoms severe enough to require antibiotics, corticosteroids, nebulized steroids/bronchodilators, or other systemic prescription medications, including suspected or confirmed bacterial infections such as bacterial tonsillitis, bacterial sinusitis, or acute suppurative otitis media.
• Acute lower respiratory tract infections, such as acute bronchitis, acute laryngitis/laryngospasm, or pneumonia.
• Respiratory tract infections secondary to underlying diseases, including primary immunodeficiency, acquired immunodeficiency syndrome, congenital airway malformation, congenital heart disease, gastroesophageal reflux, or abnormal lung development.
• Severe malnutrition.
• Severe chronic diseases, including severe asthma or other chronic respiratory diseases, chronic hepatitis or other liver diseases affecting liver function, renal insufficiency or other severe kidney diseases, neurological diseases such as epilepsy or neurodevelopmental disorders, and major genetic diseases such as chromosomal abnormalities or monogenic disorders.
• History of epilepsy or febrile convulsions.
• Planned vaccination during the trial period.
• Severe infection, severe trauma, or history of medium-to-major surgery within the past month, as judged by the investigator.
• Participation in other clinical intervention studies involving drugs, dietary supplements, probiotics, or prebiotics within the past 3 months.
• Known allergy to any component of the probiotic product.
• Any other condition that, in the opinion of the investigator, makes the participant unsuitable for this clinical study.

Sponsors & Collaborators

• Min-Tze LIONG: lead
• Shanghai 6th People's Hospital: collaborator

Study Sites (2)

Shanghai Sixth People's Hospital

Xuhui, Shanghai Municipality, 201306, China

Location

Universiti Sains Malaysia

Pulau Pinang, Pulau Pinang, 11800, Malaysia

Location

MeSH Terms

Interventions

Probiotics

Intervention Hierarchy (Ancestors)

Dietary Supplements; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Officials

• Jinping Zhang, MD

  Shanghai 6th People's Hospital

  PRINCIPAL INVESTIGATOR

Study Design

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

Study Record Dates

• First Submitted: March 23, 2026
• First Posted: March 27, 2026
• Study Start: February 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: April 2, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1); MY (1)