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We would like to invite you to participate in our study which aims to investigate whether long term dietary fibre intake influences how the bacteria within your gastrointestinal system (gut) respond to a prebiotic supplement.
Read through the information sheet carefully before making a decision on whether or not to participate. The information sheet will inform you on what the purpose of the study is, whether you meet the study inclusion criteria, what is involved in the study, the risks and benefits of participating in the study and participant rights.
If you agree to participate in the study you will need to complete a Consent Form.
Research has shown that what we eat can influence the type of bacteria in our gut. It has also been shown that the bacteria in our gut can have an influence on our health. The presence of “unfavourable” bacteria within the gut has been linked to obesity, diabetes and some gastrointestinal disorders such as inflammatory bowel disease and irritable bowel syndrome. Researchers are therefore trying to determine what can be done to ensure the bacteria living in our gut are “favourable” to help optimise our health. A number of dietary fibre supplements, known as prebiotics, have been shown to improve our health through their actions on “favourable” gut bacteria. Prebiotics are not digested by humans and therefore reach the large bowel where they are used by the gut bacteria as a source of energy.
On a day to day basis we consume dietary fibre from the foods we eat. Some people consume a large amount of dietary fibre while others consume small amounts. We believe that if someone is already consuming foods high in dietary fibre then the gut bacteria will likely respond in a different way to a prebiotic than the gut bacteria of an individual with a low intake of dietary fibre foods. The aim of the study is to determine what influence a person’s long term dietary fibre intake has on how their gut bacteria respond to a prebiotic supplement.
You are under no obligation to accept this invitation. If you decide to participate, you have the right to:
At the end of the study you will receive a $25 grocery or petrol voucher for each research unit visit (of which there are 5 in total) you attended to contribute towards your travel costs and the time you have committed to participating in the study.
All samples collected (i.e. blood and faecal) are stored in a containment laboratory and
therefore cannot be returned at the end of the study.
To be able to participate in this study you need to meet the following criteria:
*Please note: If you are taking prebiotic or probiotic containing foods or supplements and are willing to stop taking these foods or supplements for a month prior to starting the study and during the study then you are also eligible to take part in the study.
If you decide to participate in the study you will initially be asked to complete a screening questionnaire to ensure you are able to be involved in the study.
If you appear to be eligible to participate in the study the researcher will make an appointment with you to visit the Palmerston North Massey University Human Nutrition Research Unit.
At your first visit you will:
The following tests will be undertaken: liver function test, calcium, creatinine, C-reactive protein, glucose, complete blood count, potassium and sodium.
You will need to fast overnight for the blood test.
Breakfast will be provided after the blood sample has been taken
The first visit will take approximately 1 hour.
Within a week of the first visit you will be invited back to the Research Unit for a second visit.
During the second visit you will:
This visit will take around 30 minutes.
During this visit your blood test results will be reviewed. If any of the blood tests are not in the normal range you will not be eligible for inclusion in the study and you will be provided with a letter that you can take with you when you next visit your general practitioner or on request the letter can be sent to your medical practice directly.
If you are eligible for inclusion in the study you will be randomly allocated a treatment order so you receive the prebiotic and placebo in a random order. You will take both treatments over the course of the study. You and the researcher will not know what treatment you are on. This will help ensure that you and the researcher have no influence on the effect of the treatment. The total length of the study is 10 weeks. There will be a 1 week run in period, two 3 week treatment periods with a 3 week no treatment period (washout) between the treatments.
During the 3 week prebiotic treatment period you will be required to take 8g of prebiotic powder twice a day (16g in total; equivalent to around 4 teaspoons) mixed into hot and cold liquids (i.e. yoghurt, tea, coffee etc.). During the 3 week placebo treatment period you will be required to take 8g of placebo powder twice a day (16g in total; equivalent to around 4 teaspoons) mixed into hot and cold liquids. You will not receive a treatment during the 3
week no treatment period.
Throughout the study three additional visits to the Research Unit will be organised with you (5 visits in total). The third visit will occur at the end of the first 3 week treatment period.
The fourth visit will occur at the start of the second treatment period which will also be the end of the 3 week no treatment period. The final visit will occur at the end of the second treatment period.
At each of these visits you will:
These visits will take around 30 minutes each.
The 3 day diet record and appetite questionnaires are estimated to take around 45 minutes each to complete (3 hours over the duration of the study).
The FI-FFQ is estimated to take around 10 minutes to complete (40 minutes over the duration of the study).
Also over the course of the study you will be asked to complete a daily diary to record when you took the treatments and whether you experience any gastrointestinal symptoms. This will only take around 5 minutes per day to complete.
A potential benefit of being involved in this study is that you will contribute to gaining a better understanding of what influence long term dietary fibre intakes have on the responsiveness of the gut bacteria to a prebiotic.
If you are interested you can also request to be sent information relating to your body composition measurements and dietary intake analysis.
You will also receive a summary of the main findings of the study which will either be emailed or posted to you.
Some people may experience mild to moderate gastrointestinal symptoms, such as diarrhoea, bloating and flatulence/wind, as a result of taking the treatment. Often these symptoms only last a few days while your gastrointestinal system adjusts. If any adverse events occur during the study you will be immediately withdrawn.
As with all blood tests there may be some discomfort when the needle is inserted. You may also receive a bruise after the blood sample is taken, however this is unlikely.
The data will be used only for the purposes of this study and no individual will be identified. Only the researchers and administrators of the study will have access to personal information and this will be kept secure and strictly confidential. Participants will be identified only by a participant identification number. Results of this study may be published or presented at conferences or seminars. No individual will be able to be identified. At the end of this study the list of participants and their study identification number will be disposed of. Any raw data on which the results of the study depend will be retained in secure storage for 10 years, after which the data will be destroyed.
This project has been reviewed and approved by the Massey University Human Ethics Committee: Southern A, Application 15/34. If you have any concerns about the conduct of this research, please contact Mr Jeremy Hubbard, Acting Chair, Massey University Human Ethics Committee: Southern A, telephone 04 801 5799 ext 63487, email
If physical injury results from your participation in this study, you should visit a treatment provider to make a claim to ACC as soon as possible. ACC cover and entitlements are not automatic and your claim will be assessed by ACC in accordance with the Injury Prevention, Rehabilitation and Compensation Act 2001. If your claim is accepted, ACC must inform you of your entitlements, and must help you access those entitlements. Entitlements may include, but not be limited to, treatment costs, travel costs for rehabilitation, loss of earnings, and/or lump sum for permanent impairment. Compensation for mental trauma may also be included, but only if this is incurred as a result of physical injury. If your ACC claim is not accepted you should immediately contact the researcher. The researcher will initiate processes to ensure you receive compensation equivalent to that to which you would have been entitled had ACC accepted your claim.
Thank you very much for considering participating in this study
Page authorised by Head of School, School of Food and Nutrition
Last updated on Saturday 18 August 2018