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Trial registered on ANZCTR


Registration number
ACTRN12618001060235
Ethics application status
Approved
Date submitted
15/06/2018
Date registered
26/06/2018
Date last updated
26/06/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Digestive health effects of high amylose wheat in healthy Australian men and women
Scientific title
The effect of high amylose wheat on fecal butyrate and total short-chain fatty acids levels in healthy Australian men and women
Secondary ID [1] 295218 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Gut health 308372 0
Condition category
Condition code
Diet and Nutrition 307361 307361 0 0
Other diet and nutrition disorders
Oral and Gastrointestinal 307439 307439 0 0
Normal oral and gastrointestinal development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
STUDY DESIGN
The study will be designed as a completely randomised, double-blinded (where possible), controlled parallel intervention. During a 2-week low dietary fibre (<20g/day) run-in period, all participants will consume 160 g/day of the Control wheat- refined bread (Low Amylose Wheat). Participants will then be randomised to one of four groups (n=20 in each group). Each group will consume their assigned test grain products daily for a 4-week period.
The intervention test foods will be bread and biscuits containing the following type of wheat flour:
High amylose wheat – refined
High amylose wheat – wholemeal

STUDY DIET & TEST FOODS
Other than the dietary changes outlined in this study protocol, participants will maintain their habitual diets for the duration of the 6-week study (fibre intake (not including test foods) limited to <20 g/day with energy intake to remain unchanged). During the 4-week intervention period the Control refined wheat group will continue to have a fibre intake <20 g/day and fibre intakes will increase above this level for the other intervention groups. The participants will also be instructed not to consume probiotics (including probiotic yoghurts and other foods containing probiotics such as Kombucha tea and Kefir) and refrain from using fibre supplements and laxatives. Each participant will be reviewed throughout the study by a Research Dietitian to ensure these changes are achieved and maintained.
The intervention test foods will be bread and biscuits containing the following type of wheat flour:
1. High amylose wheat – refined
2. High amylose wheat – wholemeal
3. Control wheat – refined
4. Control wheat - wholemeal

Participants will be required to consume 160g of their allocated test bread and 100g of test biscuits each day. Dietitian guidance will be provided to ensure that the test foods are consumed throughout the day and are incorporated into the participant’s usual diet.

Prior to the low fibre run in participants will attend the Nutrition & Health Research Clinic and meet with a dietitian (week 0). Dietary intake will be assessed by a general diet history. This information will be used by the dietitian to help counsel the participant about consuming the low fibre diet (<20g/day). Anthropometric data will be collected by a trained Clinical Research Technician.

Two 24 hour diet recalls will be conducted over the phone on consecutive days at the end of the low fibre run-in period and at the end of the 4 week test grain period (weeks 2 and 6). These diet recalls will coincide with the 48 hr faecal collection. Daily energy, macronutrient and micronutrient intake data will be calculated using FoodWorks Professional 9 software (Xyris Software, Highgate Hill, QLD, Australia).

Dietary and study compliance will be assessed via an online survey, weekly. Survey results will be assessed by trained Clinical Research Technicians and/or Research Dietitians and contact will be made with participants if protocol deviations occur. A gut comfort questionnaire will also be completed at weeks 2, 4 and 6.

24-hour diet recall (Computer Assisted Telephone Interview)
Four computer-assisted telephone interview (CATI) 24-hour diet recall questionnaires will be completed with a research dietitian. These will be conducted over the phone at the end of the low fibre run in period (week 2) and at the end of the 4 week intervention period (week 6). These diet recalls will coincide with the 48 hour faecal collection periods. The 24 hour diet recalls require the participant to recall their food, drink and supplement intake for the previous 24 hours. The three pass methodology will be used to prompt participants to recall their intake in as much detail as possible, and reduce error by providing opportunity to remember forgotten foods. The research dietitian will enter the outcomes of the interviews directly into Foodworks at CSIRO.

Digestive Comfort questionnaire
Digestive comfort will be assessed by a validated short questionnaire which has been used in previous successful bowel health studies performed by CSIRO. It will provide semi-quantitative data and other information on bowel habits, such as defecation frequency and stool form and also abdominal disturbances (bloating, wind etc) that sometimes accompany a shift to a diet high in fibre.

Product Consumption & Accidental Intake checklist
A short checklist will be completed by participants each day to aid their adherence to the study dietary protocol and enable us to determine whether a participant has fully complied with the study design. It will also provide information that will assist with statistical analyses and interpretation of the results.

Intervention code [1] 301557 0
Lifestyle
Comparator / control treatment
The control test foods will be bread and biscuits containing the following type of wheat flour:
Control wheat – refined
Control wheat - wholemeal
Control group
Active

Outcomes
Primary outcome [1] 306333 0
Faecal total short-chain fatty acid excretion (mmol/L).
Timepoint [1] 306333 0
4 weeks post-intervention commencement
Primary outcome [2] 306334 0
Faecal total short-chain fatty acid excretion (mmol/48hr).
Timepoint [2] 306334 0
4 weeks post-intervention commencement
Primary outcome [3] 306409 0
Faecal wet weight (g/48hr)
Timepoint [3] 306409 0
4 weeks post-intervention commencement
Secondary outcome [1] 348415 0
acetate (intestinal fermentation fecal measure)
Timepoint [1] 348415 0
4 weeks post-intervention commencement
Secondary outcome [2] 348416 0
propionate (Intestinal fermentation fecal measure)
Timepoint [2] 348416 0
4 weeks post-intervention commencement
Secondary outcome [3] 348417 0
pH (Intestinal fermentation fecal measure)
Timepoint [3] 348417 0
4 weeks post-intervention commencement
Secondary outcome [4] 348419 0
phenols (Intestinal fermentation fecal measure)
Timepoint [4] 348419 0
4 weeks post-intervention commencement
Secondary outcome [5] 348420 0
p-cresol (Intestinal fermentation fecal measure)
Timepoint [5] 348420 0
4 weeks post-intervention commencement
Secondary outcome [6] 348425 0
Faecal moisture (Intestinal fermentation fecal measure)
Timepoint [6] 348425 0
4 weeks post-intervention commencement
Secondary outcome [7] 348426 0
Perceived gut comfort (Gastrointestinal Symptom Rating Scale, a validated questionnaire)
Timepoint [7] 348426 0
4 weeks post-intervention commencement
Secondary outcome [8] 348477 0
butyrate (Intestinal fermentation fecal measure)
Timepoint [8] 348477 0
4 weeks post-intervention commencement
Secondary outcome [9] 348478 0
Faecal weight (g/48hr, Intestinal fermentation fecal measure)
Timepoint [9] 348478 0
4 weeks post-intervention commencement
Secondary outcome [10] 348479 0
Defecation frequency (number of times taken to pass faeces/48hr, Intestinal fermentation fecal measure)
Timepoint [10] 348479 0
4 weeks post-intervention commencement
Secondary outcome [11] 348481 0
Faecal microbiome diversity and abundance
Timepoint [11] 348481 0
4 weeks post-intervention commencement

Eligibility
Key inclusion criteria
• Healthy adult male or female, aged 18-80 years.
• BMI 18.5-29.9 kg/m2.
• Understand the study requirements, including faecal collections and willing to adhere closely to prescribed food consumption as per the research protocol.
• Willing to maintain body weight for the duration of the study (i.e. no more than 3 kg weight loss/gain).
Minimum age
18 Years
Maximum age
80 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
EXCLUSION CRITERIA
• Received any medication or undergone surgery that in the opinion of the Principal Investigator or designee could interfere with the study and likely to modulate gut function.
• Self-reported history of alcohol or drug abuse.
• Self-reported participation in a study with any experimental drug within 30 days of commencement of the study.
• Self-reported history of diabetes, gastrointestinal, renal, hepatic disease or intestinal inflammation, including inflammatory bowel disease (Crohn’s disease and ulcerative colitis), coeliac disease, irritable bowel syndrome, chronic constipation or regular bouts of diarrhoea.
• Use of any form of medication/nutraceutical that may interfere with bowel function (such as antibiotics, laxatives, fibre supplements consumed on a regular basis).
• Known or suspected allergy, hypersensitivity or intolerance to consumption of plant-based foods which will be tested in this study.
• Night shift worker
• History of smoking within the 6 months prior to the study
• Self-reported pregnant or currently lactating women
• Extended absences due to travel or other commitments

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)
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
The effect of wheat amylose content and grain processing (refined and wholemeal flour) on changes in gut health endpoints will be determined by a two-way analysis of variance (ANOVA).
Dietary intervention adherence and gut comfort will be assessed by repeated measures two-way ANOVA. A Tukey’s post-hoc test will be used if a significant interaction is observed between amylose content and grain processing. Pearson linear regression analysis will be used to estimate correlations between parameters. These analyses will be performed using SPSS and criterion of significance will be p < 0.05.

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)
SA

Funding & Sponsors
Funding source category [1] 299806 0
Commercial sector/Industry
Name [1] 299806 0
Arista Cereal Technologies
Address [1] 299806 0
Arista Cereal Technologies Pty Ltd
56 Araba Street
ARANDA ACT 2614
AUSTRALIA
Country [1] 299806 0
Australia
Primary sponsor type
Commercial sector/Industry
Name
Arista Cereal Technologies
Address
Arista Cereal Technologies Pty Ltd
56 Araba Street
ARANDA ACT 2614
AUSTRALIA
Country
Australia
Secondary sponsor category [1] 299156 0
None
Name [1] 299156 0
Address [1] 299156 0
Country [1] 299156 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 300688 0
CSIRO Health and Medical Human Ethics Committee (CHM HREC)
Ethics committee address [1] 300688 0
Ecosciences Presinct, Dutton Park, QLD 4102
GPO Box 2583
Brisbane, QLD, 4001 Australia
Ethics committee country [1] 300688 0
Australia
Date submitted for ethics approval [1] 300688 0
24/05/2018
Approval date [1] 300688 0
13/06/2018
Ethics approval number [1] 300688 0
HREC 3/2018

Summary
Brief summary
Fibre is a component of all plant materials and in Australia is consumed in the diet largely through bread and cereals (40%) and also to a smaller extent fruits and vegetables (10 and 30% respectively). There is increasing interest in fibre, in particular, resistant starch for maintenance of large bowel health and prevention of chronic diseases such as cardiovascular disease, type 2 diabetes and certain cancers. Resistant starch, as its name suggests, resists digestion in the small intestine and travels to the large bowel where fermentation and short chain fatty acid production occur. This promotes healthy colonic function and hinders the growth of pathogenic bacteria. Unfortunately most commonly consumed starchy foods contain only very small amounts of this kind of dietary fibre. CSIRO has developed a new wheat variety containing very high levels of amylose, a form of starch that is more resistant to digestion. High amylose wheat has the potential to greatly improve resistant starch intakes in the Australian community.
The purpose of this study is to investigate the influence of high amylose wheat foods on markers of digestive health and bowel function in men and women. This clinical trial is a vital step on the path to developing staple food products that will deliver health and economic advantages for Australians.
The aim of this trial is to assess digestive health outcomes of high amylose wheat food products following daily consumption for 4 weeks, in healthy Australian men and women.
Trial website
https://www.csiro.au/en/Research/Health/Nutrition-and-health-research-clinic/Current-studies
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 84482 0
Dr Tony Bird
Address 84482 0
CSIRO
Gate 13, Kintore Avenue
Adelaide SA 5000
Country 84482 0
Australia
Phone 84482 0
+61 8 8303 8902
Fax 84482 0
Email 84482 0
tony.bird@csiro.au
Contact person for public queries
Name 84483 0
Dr Damien Belobrajdic
Address 84483 0
CSIRO
Gate 13, Kintore Avenue
Adelaide SA 5000
Country 84483 0
Australia
Phone 84483 0
+61 8 8303 8815
Fax 84483 0
Email 84483 0
damien.belobrajdic@csiro.au
Contact person for scientific queries
Name 84484 0
Dr Damien Belobrajdic
Address 84484 0
CSIRO
Gate 13, Kintore Avenue
Adelaide SA 5000
Country 84484 0
Australia
Phone 84484 0
+61 8 8303 8815
Fax 84484 0
Email 84484 0
damien.belobrajdic@csiro.au

No information has been provided regarding IPD availability
How or where can supporting documents be obtained?
Type [1] 1931 0
Informed consent form
Citation [1] 1931 0
Link [1] 1931 0
Email [1] 1931 0
Other [1] 1931 0
Statistical analysis plan is detailed in the Study Protocol
Summary results
No Results