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Trial registered on ANZCTR


Registration number
ACTRN12620000460909
Ethics application status
Approved
Date submitted
11/03/2020
Date registered
8/04/2020
Date last updated
8/04/2020
Date data sharing statement initially provided
8/04/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Assessing the glycemic lowering potential of kombucha when consumed with a high glycemic index meal by healthy volunteers with normoglycemia.
Scientific title
Assessing the glycemic lowering potential of kombucha when consumed with a high glycemic index meal by healthy volunteers with normoglycemia.
Secondary ID [1] 300686 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Glucose metabolism 316496 0
Diabetes 316497 0
Condition category
Condition code
Metabolic and Endocrine 314743 314743 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The glycemic index (GI) is a metric that ranks the glycemic potential of carbohydrate foods using a scale from 0 to 100 where glucose = 100. The GI of a given food is the relative extent to which the 50 g of available carbohydrates in a food or drink (gram for gram) raise blood glucose levels compared to an equivalent amount of pure glucose. Our studies are conducted according to the International standard for the determination of the glycemic index of foods (ISO 26642:2010).

In this instance, GI methodology will be used to assess the glycemic lowering potential of a popular fermented drink known as kombucha. A meal with and without various beverages will be fed to a group of healthy volunteers who have fasted overnight (10-12 hours fasting, water only). The meal and drink must be consumed under within 15 minutes from the first mouthful. The food will be prepared and administered by university research assistant, who will also teach the participants how to collect their own blood by finger-pricking. Fingerprick blood samples will be collected by the individual at regular intervals over 2 hours while sitting quietly in the research facility. The research assistant will prepare the blood for measuring blood glucose in the glucose autoanalyser (Beckman Coulter AU-480).The concentration of glucose in the blood will be measured and incremental area under the curve (iAUC) calculated. On another day, the same people return to our lab, and the procedures are repeated after they have consumed an equal-carbohydrate portion of the reference food (glucose sugar in water). The iAUC value for the test food/meal is expressed as a percentage of the average response produced by the reference food.
There is a 24 hour wash-out period between tests.

The meals and drinks to be tested are:
1. Reference food of 50 g glucose solution.
2. Jasmine rice, peas and soy sauce with 330mls kombucha
3. Reference food of 50 g glucose solution.
4. Jasmine rice, peas and soy sauce with 330mls soda water
5. Reference food of 50 g glucose solution.
6. Jasmine rice, peas and soy sauce with 330mls diet lemonade.
Intervention code [1] 317042 0
Treatment: Other
Comparator / control treatment
The control in this study is the meal with soda water. The meal with diet lemonade will be tested for comparison with kombucha.
Control group
Placebo

Outcomes
Primary outcome [1] 323139 0
The glycemic index for the following meals:
1. Jasmine rice, peas, soy sauce and 330mls kombucha.
2. Jasmine rice, peas, soy sauce and 330mls soda water
3. Jasmine rice, peas, soy sauce and 330mls diet lemonade.
On an individual basis blood glucose measurements are taken 5 mins before starting the meal, 0, 15, 30, 45, 60, 90 and 120 mins after the test food or reference food is consumed. The area under the curve (iAUC) for the test food is calculated relative to the glucose reference food for that individual. The final glycemic index result is the average of all the participants calculated glycemic index.
Timepoint [1] 323139 0
Blood samples are collected at -5, 0, 15, 30, 45, 60, 90 and 120 mins after the test food or reference food is consumed.
Secondary outcome [1] 380945 0
Insulin responses (expressed as iAUC) will be compared on the same basis as glycemia. The outcome is assessed from finger-prick blood samples collected at -5, 0, 15, 30, 45, 60, 90 and 120 mins after the test food or reference food is consumed and measured on a Beckman Coulter AU-480 auto-analyser.
Timepoint [1] 380945 0
Finger-prick blood samples collected at -5, 0, 15, 30, 45, 60, 90 and 120 mins after the test food or reference food is consumed

Eligibility
Key inclusion criteria
Healthy volunteers with normal glucose tolerance.
Minimum age
18 Years
Maximum age
50 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Individuals with impaired glucose metabolism.

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)
Not possible.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The 3 meals will be fed in random order.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
The same participants will test all 3 meals on 3 separate days:
1. Jasmine rice, peas, soy sauce and 330mls kombucha.
2. Jasmine rice, peas, soy sauce and 330mls soda water
3. Jasmine rice, peas, soy sauce and 330mls diet lemonade.
and on another 3 visits consume the 50gm glucose drink (on separate days).
In total 6 data collection days.
Phase
Not Applicable
Type of endpoint(s)
Bio-availability
Statistical methods / analysis
Paired t test for kombucha meal vs soda water meal.
Paired t test for kombucha meal vs diet lemonade meal.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 29573 0
2006 - The University Of Sydney

Funding & Sponsors
Funding source category [1] 305130 0
University
Name [1] 305130 0
The University of Sydney
Address [1] 305130 0
Level 6 Charles Perkins centre D17 The University of Sydney NSW 2006
Country [1] 305130 0
Australia
Primary sponsor type
University
Name
The University of Sydney
Address
Level 6 Charles Perkins centre D17 The University of Sydney NSW 2006
Country
Australia
Secondary sponsor category [1] 305490 0
Commercial sector/Industry
Name [1] 305490 0
The Good Brew Company Pty Ltd
Address [1] 305490 0
54 Hope Street, Brunswick Victoria, 3056
Country [1] 305490 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 305500 0
The University of Sydney NSW Human Research Ethics Committee
Ethics committee address [1] 305500 0
Office of Research Integrity/Research Portfolio
Level 6, Jane Foss Russell Building G02
The University of Sydney
NSW 2006
Ethics committee country [1] 305500 0
Australia
Date submitted for ethics approval [1] 305500 0
15/11/2017
Approval date [1] 305500 0
15/11/2017
Ethics approval number [1] 305500 0
2017/801

Summary
Brief summary
The primary goal of this study is to assess if a 330ml kombucha drink will reduce the glycemic response to a meal.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 100578 0
Prof Jennie Brand-Miller
Address 100578 0
Level 6 Charles Perkins Centre D17 The University of Sydney, 2006 NSW
Country 100578 0
Australia
Phone 100578 0
+61 0293513759
Fax 100578 0
Email 100578 0
jennie.brandmiller@sydney.edu.au
Contact person for public queries
Name 100579 0
Dr Roslyn Muirhead
Address 100579 0
Level 6 Charles Perkins Centre D17 The University of Sydney, 2006 NSW
Country 100579 0
Australia
Phone 100579 0
+61 2 86271936
Fax 100579 0
Email 100579 0
roslyn.muirhead@sydney.edu.au
Contact person for scientific queries
Name 100580 0
Prof Jennie Brand-Miller
Address 100580 0
Level 6 Charles Perkins Centre D17 The University of Sydney, 2006 NSW
Country 100580 0
Australia
Phone 100580 0
+61 0293513759
Fax 100580 0
Email 100580 0
jennie.brandmiller@sydney.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
This is industry contract testing.
What supporting documents are/will be available?
No other documents available
Summary results
No Results