Probiotics and vitamin C for the management of upper respiratory tract infections

An investigation of the efficacy of long term consumption of a probiotic and vitamin C combination on the prevention of upper respiratory tract infections in children attending preschool or primary school

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN26587549

Enrollment

200

Registered

2019-10-16

Start date

2016-12-15

Completion date

Unknown

Last updated

2025-01-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Respiratory tract infections in children Respiratory

Interventions

Eligible subjects will be allocated in a 1:1 ratio to the two arms of the study according to a computer-generated random sequence using block randomisation with a block-size of four and stratified by

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Healthy children of either sex attending preschool facilities (3-6 years old) or primary school (7-10 years old) 2. Children with no flu vaccination 3. Parents/guardian who are willing to give written informed consent 4. Children who are willing to avoid any other probiotic supplements or dairy probiotic products (probiotic yoghurt, acidophilus milk, kefir etc.) for the duration of the project 5. Provision of faecal sample at the beginning and the end of the study will be voluntary

Exclusion criteria

Exclusion criteria: 1. Parents are unable/unwilling to give written informed consent 2. Taking regularly any dairy probiotic product (probiotic yoghurt, acidophilus milk, kefir, etc) 3. Taking regularly any probiotic and prebiotic supplements 4. Taking medication to stimulate the immune system 5. Taking regularly Vitamin C 6. Sensitive to xylitol/sorbitol

Design outcomes

Primary

Measure	Time frame
The incidence and duration of URTI assessed using daily health diaries completed by parents/guardians over the six month study period	—

Secondary

Measure	Time frame
Over the six month study period: 1. Absence from preschool or primary school assessed using the daily health diaries completed by parents/guardians 2. Antibiotic prescriptions assessed using the daily health diaries completed by parents/guardians and paediatric physician’s records 3. Lower respiratory tract infections assessed using the paediatric physician’s records 4. Gastrointestinal symptoms, such as change in bowel habits, vomiting, stomach ache, assessed using the daily health diaries completed by parents/guardians 5. Microbiota composition, diversity and functionality assessed using next-generation sequencing, traditional culture methods and 1H NMR spectroscopic analysis. The faecal sample collection is from a single centre and on a voluntary basis at day 0 (baseline) and 6 months	—

Measure

Time frame

Over the six month study period: 1. Absence from preschool or primary school assessed using the daily health diaries completed by parents/guardians 2. Antibiotic prescriptions assessed using the daily health diaries completed by parents/guardians and paediatric physician’s records 3. Lower respiratory tract infections assessed using the paediatric physician’s records 4. Gastrointestinal symptoms, such as change in bowel habits, vomiting, stomach ache, assessed using the daily health diaries completed by parents/guardians 5. Microbiota composition, diversity and functionality assessed using next-generation sequencing, traditional culture methods and 1H NMR spectroscopic analysis. The faecal sample collection is from a single centre and on a voluntary basis at day 0 (baseline) and 6 months

—

Countries

Slovakia

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 9, 2026