Trial Review

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12625000807459p
Ethics application status
Not yet submitted
Date submitted
26/06/2025
Date registered
29/07/2025
Date last updated
29/07/2025
Date data sharing statement initially provided
29/07/2025
Type of registration
Prospectively registered

Titles & IDs
Public title
OAK Study: Oligosaccharides during Antibiotic treatment in Kids
Scientific title
Can complex breastmilk sugars protect the gut microbiome during antibiotic therapy in young children, reducing rapid weight gain and allergic diseases?
Secondary ID [1] 314743 0
None
Universal Trial Number (UTN)
U1111-1324-5170
Trial acronym
OAK
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 337956 0
Childhood atopic eczema 337957 0
Wheezing Illnesses 337958 0
Infection, unspecified 337959 0
Condition category
Condition code
Metabolic and Endocrine 334274 334274 0 0
Other metabolic disorders
Skin 334275 334275 0 0
Dermatological conditions
Respiratory 334276 334276 0 0
Other respiratory disorders / diseases
Infection 334277 334277 0 0
Other infectious diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Study nutritional supplement: 1.5g of prebiotics (per gram: 2'-Fucosyllactose 540mg, Lacto-N-tetraose 150mg, Lacto-N-neotetraose 140mg, 6'-Sialyllactose 120mg, 3'-Sialyllactose 50mg; collectively also known as complex breastmilk sugars) and 1.5g skim milk powder to be reconstituted with 15mL water; and administered in three divided doses over a day.

Participant caregivers will be shown how to reconstitute and administer the first dose.
Course: 10 days commencing with oral antibiotic therapy.
Adherence monitoring: daily text message reminders to participant caregivers to administer intervention. 2 phone reviews with caregivers during the intervention course to ask about doses successfully administered.

The first participants enrolled will be asked to form the sub-group by providing two extra stool samples, until we reach sufficient numbers. The exclusion criterion for participation in the subgroup will be initial stool collection more than 48 hours from starting antibiotics.
The sub-group will involve a total sample size of 90 (45 per group) to be sufficiently powered to detect a significant short-term reduction in Bifidobacterium bifidum relative abundance.
The sub-group will have two extra brief visits by research staff, primarily for collection of stool samples on days 10 and 28 post-randomisation.
Intervention code [1] 331349 0
Treatment: Other
Comparator / control treatment
1.5g skim milk powder to be reconstituted with 15mL water; and administered orally in three divided doses over a day.
Course: 10 days commencing with oral antibiotic therapy.
Control group
Placebo

Outcomes
Primary outcome [1] 341937 0
Weight
Timepoint [1] 341937 0
Baseline, 6months, 12 months (primary timepoint) and 18 months post-randomisation
Secondary outcome [1] 449065 0
Weight gain
Timepoint [1] 449065 0
12 and 18 months post-randomisation
Secondary outcome [2] 449066 0
Gut microbiome composition
Timepoint [2] 449066 0
Baseline and 6, 12 and 18 months post-randomisation With a sub-group having additional stool analyses at 10 and 28 days post-randomisation.
Secondary outcome [3] 449067 0
Wheezing illnesses: incidence
Timepoint [3] 449067 0
Baseline, 6, 12 and 18 months post-randomisation
Secondary outcome [4] 449068 0
Childhood atopic eczema: incidence
Timepoint [4] 449068 0
Baseline, 6, 12 and 18 months post-randomisation
Secondary outcome [5] 449069 0
Infection, unspecified: incidence of non-wheezing infectious illnesses
Timepoint [5] 449069 0
6, 12 and 18 months post-randomisation
Secondary outcome [6] 449550 0
Wheezing illnesses: severity
Timepoint [6] 449550 0
Baseline, 6, 12 and 18 months post-randomisation
Secondary outcome [7] 449552 0
Childhood atopic eczema: severity
Timepoint [7] 449552 0
Baseline, 6, 12 and 18 months post-randomisation

Eligibility
Key inclusion criteria
- Aged 12 to 15 months
- Have mostly stopped taking breastmilk or formula
- Residence in the Auckland region
- Prescribed a course of oral antibiotics for an acute infection
- Caregiver able and willing to provide written informed consent and complete questionnaires in English
Minimum age
12 Months
Maximum age
15 Months
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
- Severe chronic conditions requiring repeated hospitalisations
- Major congenital anomaly or chronic condition expected to affect growth or immune function (e.g. cystic fibrosis)
- Prior gastrointestinal surgery (e.g. bowel resection or stoma)
- Hospitalised at time of recruitment
- Frequent watery stools
- Preterm birth
- Small for gestational age (SGA)
- >100mL/ day infant/ toddler follow-on formula containing pre-biotic oligosaccharides
- Ongoing intake of a specific probiotic supplement
- Antibiotics within 4 weeks of enrolment (excluding the current course)

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Concealed: allocation involves contacting the holder of the allocation schedule who is independent of the study team at central administration site.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Random
The allocation sequence will be computer generated using permuted, varying blocks of 2 and 4; participants assigned in a 1:1 ratio to placebo or active treatment.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
11/08/2025
Actual
Date of last participant enrolment
Anticipated
31/08/2026
Actual
Date of last data collection
Anticipated
3/03/2028
Actual
Sample size
Target
212
Accrual to date
Final
Recruitment outside Australia
Country [1] 27140 0
New Zealand
State/province [1] 27140 0

Funding & Sponsors
Funding source category [1] 319296 0
Charities/Societies/Foundations
Name [1] 319296 0
Rank Group Foundation
Country [1] 319296 0
New Zealand
Primary sponsor type
University
Name
University of Auckland
Address
Country
New Zealand
Secondary sponsor category [1] 321770 0
None
Name [1] 321770 0
Address [1] 321770 0
Country [1] 321770 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 317874 0
Northern B Health and Disability Ethics Committee 
Ethics committee address [1] 317874 0
Ethics committee country [1] 317874 0
New Zealand
Date submitted for ethics approval [1] 317874 0
05/08/2025
Approval date [1] 317874 0
Ethics approval number [1] 317874 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 142426 0
Prof Wayne Cutfield
Address 142426 0
Liggins Institute, University of Auckland, Private Bag 92019, Victoria St West, Auckland 1142
Country 142426 0
New Zealand
Phone 142426 0
+64 21734441
Fax 142426 0
Email 142426 0
[email protected]
Contact person for public queries
Name 142427 0
Wayne Cutfield
Address 142427 0
Liggins Institute, University of Auckland, Private Bag 92019, Victoria St West, Auckland 1142
Country 142427 0
New Zealand
Phone 142427 0
+64 21734441
Fax 142427 0
Email 142427 0
[email protected]
Contact person for scientific queries
Name 142428 0
Wayne Cutfield
Address 142428 0
Liggins Institute, University of Auckland, Private Bag 92019, Victoria St West, Auckland 1142
Country 142428 0
New Zealand
Phone 142428 0
+64 21734441
Fax 142428 0
Email 142428 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.