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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
The Effect of SunGold Kiwifruit on Gut Health Function
Scientific title
A randomised, controlled, single blinded cross-over trial to investigate the effect of Zespri SunGold kiwifruit on digestive health and gut health function in individuals with constipation with or without Irritable Bowel Syndrome.
Secondary ID [1] 287142 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Constipation 295690 0
Irritable Bowel Syndrome 299101 0
Condition category
Condition code
Oral and Gastrointestinal 295967 295967 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon
Diet and Nutrition 295968 295968 0 0
Other diet and nutrition disorders

Study type
Description of intervention(s) / exposure
The study duration is a total of 16 weeks; 2-week lead in, 4-week intervention, 4-week washout, 4-week intervention, and final 2-week follow up. The cross-over design will be completed using the kiwifruit intervention (3 SunGold kiwifruit per day (Actinidia chinensis 'Zesy002)), compared to a positive control intervention of psyllium (Two and a half teaspoons of Metamucil(Registered trademark) per day providing 5.0g fibre). The kiwifruit and Metamucil (Registered trademark) can be consumed in two doses, preferably one dose in the morning and one dose at night. There is no restriction as to what other foods are consumed with them. Adherence to the treatments is measured by a daily diary and food diaries at the end of each treatment. The lead-in period requires individuals to stop taking laxatives and kiwifruit.
Intervention code [1] 292404 0
Treatment: Other
Intervention code [2] 292405 0
Comparator / control treatment
Participants will be asked to consume two and a half teaspoons of Metamucil(Registered Trademark) as the control for this study. This treatment phase is 4 weeks in duration. The Metamucil(Registered Trademark) will be provided as a powder and participants will be instructed to consume the Metamucil(Registered Trademark) in conjunction with sufficient cool fluid (at least 250ml).
Control group

Primary outcome [1] 295648 0
Complete Spontaneous Bowel Movement (CSBM) Frequency (CSBM/week) as a measure of overall bowel function in constipation. The number, or occurrence, of CSBM is recorded by all participants in a daily dairy recording bowel movements. A spontaneous bowel movement (SBM) is defined as a stool not induced by rescue medication. A CSBM is defined as a SBM associated with a sensation of complete evacuation.
Timepoint [1] 295648 0
CSBM will be measured daily across the 16 week study
Secondary outcome [1] 316090 0
The frequency of bowel movements (BM)
Timepoint [1] 316090 0
Measured daily through the daily dairy for the entire 16 week duration of the study.
Secondary outcome [2] 316091 0
Ease of defecation/level of straining. Measured by a question in the daily diary (e.g. Did you have to use strain in order to defecate at any of the times you had a bowel movement?)
Timepoint [2] 316091 0
Measured daily through the daily dairy for the entire 16 week duration of the study.
Secondary outcome [3] 316092 0
Stool form (Bristol Stool Scale).
Timepoint [3] 316092 0
Measured daily through the daily dairy for the entire 16 week duration of the study.
Secondary outcome [4] 316093 0
Gastrointestinal Symptom Rating Scale (GSRS). Used to determine the potential effect of kiwifruit on the gastrointestinal symptoms and pain, together with stool habit. The GSRS uses questions to assess symptom severity using a 7-grade Likert scale ranging from 1 ("no discomfort at all") to 7 ("very severe discomfort")
Timepoint [4] 316093 0
Measured weekly during the entire 16 week duration of the study through an interview with a researcher. Participants will be asked to answer questions in relation to the previous week.
Secondary outcome [5] 316094 0
Quality of life. This is measured via an End of Study Period Quality of Life (IBS-QOL) Evaluation.
Timepoint [5] 316094 0
Completed at the start of the trial (at enrolment) and at the end of each study period (end of week 2, end of week 6, end of week 10, end of week 14 and end of week 16)

Key inclusion criteria
Functionally Constipated Group and Irritable Bowel Sydrome with constipation group: Adult (18-65 years), BMI 18-25, Both male and female (females will be required to declare stage of menstrual cycle during different trial stages), Presence of Functional Constipation or Irritable Bowel Syndrome according to ROME III diagnostic criteria.
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. Alarm features associated with bowel habit (recent changes in bowel habit (<3 months), rectal bleeding, weight loss, blood in stools, bleeding haemorrhoids, family history of Gastrointestinal (GI) cancer or Irritable Bowel Disease (IBD).

2. Chronic disease (cardiovascular, cancer, renal failure, previous GI surgery (not including appendectomy or cholecystectomy), neurological conditions (e.g. stroke, spinal chord injury, multiple sclerosis)

3. Fasting blood glucose of 6.0 mmol/l or greater. Participants will be screened during recruitment.

4. Participants with diagnosed and stable conditions requiring the use of selective serotonin uptake inhibitors, triglycerides, opiates or anti-inflammatories will only be permitted into the trial on condition that the medication has been in use continually and the condition has been stable for > 3 months. Similarly those with stable and controlled diabetes for > 3 months will also be permitted to take part in the study.

5. Women who are pregnant, breastfeeding or planning a pregnancy in the 3 months post selection will be excluded.

6. Potential participants with known kiwifruit or latex allergy will be excluded.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will be enrolled by investigators following a face to face interview and given a unique identifying number (ID) for labelling all further trial data. The ID number will be provided to an independent biostatistician who will randomise the participants to the treatment schedule.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
The study is designed to detect an increase of 1.0 or more CSBM per week in functionally constipated and Irritable Bowel Syndrome individuals with constipation.

An initial calculation has been completed using available data. Based on previous studies, the standard deviation for the primary outcome (number of CSBM per week) is 1.41. In order to detect an increase in CSBM of 1.0 per week in the treatment group compared to the control group, with 80% power and 5% significance, 47 subjects are required to complete the trial. This is based on an unpublished study carried out in Europe in 2014. In order to allow for dropouts, a total of 50 individuals will be recruited.

All statistical analysis will be completed by an independent bio-statistician. Statistical analysis will describe the relationship between the consumption of kiwifruit and the parameters of bowel habit and digestive comfort measured. In addition the analysis will compare the effects of the two treatment (kiwifruit and Metamucil(Registered Trademark)) and determine the effects of the two treatments. P values of 0.05 or less will be considered significant.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 7049 0
New Zealand
State/province [1] 7049 0

Funding & Sponsors
Funding source category [1] 291708 0
Commercial sector/Industry
Name [1] 291708 0
Zespri International Ltd
Address [1] 291708 0
40 Maunganui Road
Mt Maunganui
New Zealand 3116
Country [1] 291708 0
New Zealand
Primary sponsor type
Government body
The New Zealand Institute for Plant & Food Research
Gerald Street
Christchurch 8140
New Zealand
Secondary sponsor category [1] 290383 0
Name [1] 290383 0
Address [1] 290383 0
Country [1] 290383 0

Ethics approval
Ethics application status
Ethics committee name [1] 293230 0
Health and Disability Ethics Commitee
Ethics committee address [1] 293230 0
Ministry of Health
20 Aitken Street
Wellington 6011
Ethics committee country [1] 293230 0
New Zealand
Date submitted for ethics approval [1] 293230 0
Approval date [1] 293230 0
Ethics approval number [1] 293230 0

Brief summary
Gastrointestinal discomfort, including constipation, is a common condition throughout the world, which often leads to a reduction in the quality of life. The prevelance of constipation is reported to affect around 15% of adults in the western world. The consumption of green kiwifruit is recognised to assist with the relief of constipation and provide potential relief of gastrointestinal symptoms. A more recently commerecialised cultivar marketed as SunGold may also have a similar effect.
The aim of this study is to examine the effect of daily consumption of three SunGold kiwifruit in individuals who suffer from functional constipation or irritable bowel syndrome with constipation to determine if kiwifruit can improve bowel regularity, digestive discomfort, digestive health and function and gut health.
The effect of the kiwifruit will be compared with psyllium (Metamucil(Registered Trademark)), a bowel bulking agent that has been shown to be an effective treatment for constipation. The trial is a randomised, single-blinded cross-over study where individuals will consume either 3 SunGold kiwifruit daily for four weeks or 2.5 teaspoons of Metamucil(Registered Trademark) powder for four weeks. There will be a four week washout period and then the participants will swap over treatments for a further four weeks. The trial will start and finish with a 2 week washout period. Participants will be asked to complete a daily diary to record bowel movement and general wellbeing during the study. Faecal samples and blood will be collected at the beginning of the trial and at the end of each treatment period. Participants will also be asked to complete at questionnaire relating to bowel health at these points.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 58986 0
Prof Richard Gearry
Address 58986 0
Gastroenterology and Endoscopy Specialists
Level 1
40 Stewart Street
Christchurch 8140
Country 58986 0
New Zealand
Phone 58986 0
+64 3 378 6236
Fax 58986 0
Email 58986 0
Contact person for public queries
Name 58987 0
Dr Alison Wallace
Address 58987 0
New Zealand Institute for Plant and Food Research
Private Bag 4704
Christchurch 8140
Country 58987 0
New Zealand
Phone 58987 0
+64 3 325 9638
Fax 58987 0
+64 3 325 2074
Email 58987 0
Contact person for scientific queries
Name 58988 0
Dr Alison Wallace
Address 58988 0
New Zealand Institute for Plant and Food Research
Private Bag 4704
Christchurch 8140
Country 58988 0
New Zealand
Phone 58988 0
+64 3 325 9638
Fax 58988 0
+64 3 325 2074
Email 58988 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary