Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12621001558819
Ethics application status
Approved
Date submitted
8/10/2021
Date registered
17/11/2021
Date last updated
23/02/2024
Date data sharing statement initially provided
17/11/2021
Date results information initially provided
23/02/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
The influence of kefir consumption on the intestinal microbiome of healthy adults – a pilot study
Scientific title
The influence of kefir consumption on the intestinal microbiome of healthy adults – a pilot study
Secondary ID [1] 305496 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Prevention of gastrointestinal disease 324130 0
Condition category
Condition code
Oral and Gastrointestinal 321394 321394 0 0
Normal oral and gastrointestinal development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Commercially available kefir drink based on fermented full-cream cow milk. The kefir has no thickeners/gels and is made with unhomogenised fresh milk from free range pasture fed cows.
Participants take the kefir at home, 200ml per day in total, taken twice daily (100ml in the morning, 100ml in the evening)
The intervention is for 14 days in total, and consumption will be monitored via a diary, in which participants indicate whether they have used the intervention as directed
Intervention code [1] 321898 0
Lifestyle
Intervention code [2] 322056 0
Treatment: Other
Comparator / control treatment
Commercially available kefir drink based on fermented full-cream cow milk. The kefir has no thickeners/gels and is made with unhomogenised fresh milk from free range pasture fed cows.
Participants take the kefir at home, 400ml per day in total, taken twice daily (200ml in the morning, 200ml in the evening)
The intervention is for 14 days in total, and consumption will be monitored via a diary, in which participants indicate whether they have used the intervention as directed
Control group
Dose comparison

Outcomes
Primary outcome [1] 329166 0
Oral microbiome profile
Saliva swabs will be assessed using Amplicon Sequencing – 16S to determine the oral microbial profile
Timepoint [1] 329166 0
14 days post-commencement of intervention
Primary outcome [2] 329167 0
Gut microbiome profile
Stool samples will be assessed using Amplicon Sequencing – 16S to determine the gut microbial profile
Timepoint [2] 329167 0
14 days post-commencement of intervention
Secondary outcome [1] 401705 0
Oral microbiome profile
Saliva swabs will be assessed using Amplicon Sequencing – 16S to determine the oral microbial profile
Timepoint [1] 401705 0
28 days post-commencement of intervention
Secondary outcome [2] 401706 0
Gut microbiome profile
Stool samples will be assessed using Amplicon Sequencing – 16S to determine the gut microbial profile
Timepoint [2] 401706 0
28 days post-commencement of intervention
Secondary outcome [3] 401708 0
Compliance via consumption of recommended doses, data collected via participant diary
Timepoint [3] 401708 0
Daily from baseline to 14 days post-commencement of intervention
Secondary outcome [4] 401709 0
Acceptability via participant feedback, open question on participant's experiences with the trial intervention
Timepoint [4] 401709 0
Daily from baseline to 14 days post-commencement of intervention
Secondary outcome [5] 401710 0
Safety via adverse events (diary, phone interview)
Timepoint [5] 401710 0
14 days, and 28 days after commencement of the intervention
Secondary outcome [6] 402345 0
Safety via gastrointestinal symptoms (Structured Assessment of Gastrointestinal Symptoms instrument - SAGIS, Koloski et al., 2017)
Timepoint [6] 402345 0
14 days, and 28 days after commencement of the intervention

Eligibility
Key inclusion criteria
Healthy
BMI 18.5-29.9
Minimum age
18 Years
Maximum age
45 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
- Acute illness (injury, infection)
- Chronic gastrointestinal conditions (inflammatory or functional bowel diseases, celiac disease, food intolerance or allergies (especially milk), lactose intolerance
- Use of long-term medication
- Use of antimicrobial medication (incl. antibiotics) in the previous 6 months
- Regular use of pre-, pro-, or synbiotics in the previous 6 months, specifically natural yogurt, probiotic drinks, or products (at least once weekly)
- Consumption of fermented foods for health purpose within the last 2 months, specifically kefir, sauerkraut, kombucha, miso, kimchi (occasional consumption is acceptable)
- Diet prescribed for medical purposes
- Recent lifestyle changes (including new dietary regimen, or uptake of exercise regimen)
- Women currently undergoing menopause, and women who are pregnant, or breastfeeding

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)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
10/01/2022
Actual
4/10/2022
Date of last participant enrolment
Anticipated
30/11/2022
Actual
7/09/2023
Date of last data collection
Anticipated
31/12/2022
Actual
20/10/2023
Sample size
Target
24
Accrual to date
Final
18
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 35502 0
2480 - Lismore

Funding & Sponsors
Funding source category [1] 309855 0
University
Name [1] 309855 0
Southern Cross University
Country [1] 309855 0
Australia
Primary sponsor type
University
Name
Southern Cross University
Address
Military Rd
East Lismore NSW 2480
Australia
Country
Australia
Secondary sponsor category [1] 310890 0
University
Name [1] 310890 0
University of New South Wales Microbiome Research Centre
Address [1] 310890 0
St George and Sutherland Clinical School
Faculty of Medicine & Health
UNSW SYDNEY NSW 2052
Country [1] 310890 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 309592 0
Southern Cross University Human Research Ethics Committee
Ethics committee address [1] 309592 0
Southern Cross University
PO Box 157, Lismore NSW 2480
Ethics committee country [1] 309592 0
Australia
Date submitted for ethics approval [1] 309592 0
Approval date [1] 309592 0
24/09/2021
Ethics approval number [1] 309592 0
2021/129
Ethics committee name [2] 309593 0
The University of New South Wales Research Ethics Committee
Ethics committee address [2] 309593 0
Research Ethics & Compliance Support
UNSW Sydney
Sydney NSW 2052 Australia
Ethics committee country [2] 309593 0
Australia
Date submitted for ethics approval [2] 309593 0
Approval date [2] 309593 0
01/10/2021
Ethics approval number [2] 309593 0
2021/RL00200

Summary
Brief summary
The human digestive tract, especially the gut, is populated by millions of microorganisms including bacteria, and fungi, the so-called microbiome. Many studies have shown that the microbiome is linked to health from digestive disorders, to heart health, or mental health. The microbiome can be modified by your diet, and probiotics are frequently advertised to alter the gut microbiome. One such product is kefir, a probiotic dairy beverage that has been consumed for over 2,000 years. Traditional kefir is produced by taking for example cow’s milk, and adding Kefir ‘grains’ which contain a diverse range of symbiotic bacteria and yeast species. Anecdotal statements in the media continue to link the consumption of Kefir to gut health, despite a lack of scientific evidence to support this. In order to advance the scientific understanding of Kefir, this study aims to examine whether kefir consumption leads to changes in the oral and gut microbiome, i.e. the bacteria living in the digestive tract. It is hypothesised, that kefir will increase the number of beneficial bacteria in the mouth and gut.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 114702 0
A/Prof Romy Lauche
Address 114702 0
National Centre for Naturopathic Medicine
Southern Cross University
Military Rd
East Lismore NSW 2480
Country 114702 0
Australia
Phone 114702 0
+61 266203362
Fax 114702 0
Email 114702 0
romy.lauche@scu.edu.au
Contact person for public queries
Name 114703 0
A/Prof Romy Lauche
Address 114703 0
National Centre for Naturopathic Medicine
Southern Cross University
Military Rd
East Lismore NSW 2480
Country 114703 0
Australia
Phone 114703 0
+61 266203362
Fax 114703 0
Email 114703 0
ncnmtrials@scu.edu.au
Contact person for scientific queries
Name 114704 0
A/Prof Romy Lauche
Address 114704 0
National Centre for Naturopathic Medicine
Southern Cross University
Military Rd
East Lismore NSW 2480
Country 114704 0
Australia
Phone 114704 0
+61 266203362
Fax 114704 0
Email 114704 0
romy.lauche@scu.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


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.