Plain English Summary
Background and study aims
High fibre diets are known to be related to a number of health benefits and have been widely advertised (in breakfast cereals, for example) as a way of helping people to lose weight. Short chain fatty acids, one of the breakdown products of fibre, may be responsible for the beneficial effects of fibre. One specific short chain fatty acid, propionate, may be associated with a reduction in feelings of hunger. Different dietary fibres produce different amounts of propionate. It is currently unknown which dietary fibres produce the largest amounts of propionate and whether they affect appetite (i.e. how hungry or full you feel). The aim of this study is to find out the effects of a range of dietary fibres on propionate levels and appetite. This may be important in terms of controlling body weight and therefore preventing obesity.
Who can participate?
Healthy men and women, aged 18-65, who are either normal weight or overweight
What does the study involve?
There are two parts to this study. Part A and B both consist of three separate study visits. In Part A, on the study days participants receive a standard breakfast containing 25g of one of three food supplements and two non-radioactive tracer molecules, which are used to track the digestive process. A standard snack and meal is also provided. Participants complete questionnaires to measure appetite, and breath and blood samples are collected. In Part B, participants are instructed to consume one of the three dietary supplements from Part A in an increased dose for 7 days before each of the three study visits. On study days, participants consume a standard breakfast, which contains 25 g of the same dietary supplement that they have been taking. A snack and buffet meal are also provided. The following measurements are collected: amount of propionate in blood, appetite ratings using questionnaires, food intake at a buffet meal (where participants are instructed to eat until they feel comfortably full) and breath hydrogen samples.
What are the possible benefits and risks of participating?
Volunteers will not benefit directly from this study but the results may help doctors in the future treat patients with obesity. Some of the procedures in this study, such as the recording of your weight, height and blood pressure, and the collection of breath samples, present no risk. Taking blood samples can cause mild discomfort when the needle is inserted, and possible bruising and infection in that area. These procedures will only be carried out by experienced healthcare professionals under germ-free conditions in order to minimise such risks. As with any high fibre diet, volunteers may experience tummy bloating and discomfort. There is also a small chance that volunteers may experience episodes of diarrhoea during the study. In order to minimise the risk of this happening, in Part B the total dose of dietary supplement being consumed will be increased slowly over the course of the 7 days before each study visit. Volunteers may also find the taste of the dietary supplements unpleasant and so will be advised on the best way to add it into your diet. The addition of the dietary supplement to their daily routine will be an inconvenience and will require a change in lifestyle. To minimise inconvenience, all supplements will be provided in ready-to-use sachets.
Where is the study run from?
Hammersmith Hospital (UK)
When is the study starting and how long is it expected to run for?
August 2014 to July 2015
Who is funding the study?
Medical Research Council (MRC) (UK)
Who is the main contact?
Miss Claire Byrne
Claire.byrne@imperial.ac.uk
Trial website
Contact information
Type
Scientific
Primary contact
Miss Claire Byrne
ORCID ID
http://orcid.org/0000-0001-7578-6237
Contact details
Du Cane Road
London
W12 0NN
United Kingdom
-
Claire.byrne@imperial.ac.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
16769
Study information
Scientific title
The effect of short-term dietary supplementation of fermentable carbohydrates on propionate production and appetite measures: a pilot study
Acronym
Study hypothesis
The aim of this study is to investigate whether short-term dietary supplementation of fermentable carbohydrate (FC) increases plasma propionate concentrations and suppresses appetite in humans.
Ethics approval
NRES Committee London Harrow, 16/06/2014, ref. 14/LO/0704
Study design
Randomised single-blind cross-over feeding study
Primary study design
Interventional
Secondary study design
Randomised cross over trial
Trial setting
Other
Trial type
Prevention
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Condition
Topic: Primary Care; Subtopic: Not Assigned; Disease: All Diseases
Intervention
Current interventions as of 11/10/2017:
This will be a study comparing the effects of L-rhamnose on appetite and plasma propionate concentrations, with inulin and cellulose. This study will involve three separate 7-day feeding periods followed by study days, with a 2-week wash-out period between study visits. This study will be preceded by a protocol optimisation study, which will involve three separate study visits. Inulin will be used as a positive control (as we know it is fermented in the colon) and cellulose as a negative control (as we know it does not ferment significantly in the colon) in both studies. Two studies are proposed: an optimisation study to assess the effect of FCs on gut transit time and therefore optimise sampling regimens, and a feeding study to assess the effect of FCs on appetite.
In the Optimisation Study, participants will consume 25 g of one of the three dietary supplements on each of the three study days according to their randomisation pattern.
In the Feeding Study, participants will consume a different dietary supplement in a stepped dose for 7 days prior to each one of the three study visits (final daily dose 25 g). On study days, volunteers will receive 25 g of the appropriate dietary supplement with their breakfast.
Randomisation will be conducted by sealed envelopes once the participants have successfully passed the health screening. The participants will be blinded as to the type of supplement they are taking.
Previous interventions:
This will be a study comparing the effects of B-glucan (fermentable, soluble and viscous) on appetite and plasma propionate concentrations, with inulin (fermentable, soluble and non-viscous), cellulose (non-fermentable, insoluble and non-viscous) and methyl cellulose (non-fermentable, soluble and viscous). This study will involve four separate 7-day feeding periods followed by study days, with a 2-week wash-out period between study visits. This study will be preceded by a protocol optimisation study, which will involve four separate study visits. Inulin will be used as a positive control (as we know it is fermented in the colon) and cellulose as a negative control (as we know it does not ferment significantly in the colon) in both studies. The addition of methyl cellulose (a non-fermentable, soluble and viscous product) as a fourth leg to both studies will allow for the assessment of the effect of viscosity on appetite measures. Two studies are proposed: an optimisation study to assess the effect of FCs on gut transit time and therefore optimise sampling regimens, and a feeding study to assess the effect of FCs on appetite.
In the Optimisation Study, participants will consume 10 g of one of the four dietary supplements on each of the four study days according to their randomisation pattern.
In the Feeding Study, participants will consume a different dietary supplement in a stepped dose for 7 days prior to each one of the four study visits. Participants will consume 10 g of the appropriate dietary supplement on day 1, two 10 g servings on days 2-3 (total daily dose 20 g), and three 10 g servings on days 4-7 (total daily dose 30 g). On study days, volunteers will receive 10 g of the appropriate dietary supplement with their breakfast. The maximum dose used in this study is based on previous work carried out by our research group.
Randomisation will be conducted by sealed envelopes once the participants have successfully passed the health screening. The participants will be blinded as to the type of supplement they are taking.
Intervention type
Supplement
Phase
Drug names
Primary outcome measure
Appetite; Timepoint(s): measures every 30 minutes over the study period
Secondary outcome measures
1. 13CO2 enriched breath hydrogen; Timepoint(s): measure every 30 minutes over the time period
2. Plasma propionate; Timepoint(s): measured every 30 minutes over the study period
Overall trial start date
01/08/2014
Overall trial end date
31/07/2015
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Body Mass Index (BMI) 20-35 kg/m2
2. Age 18-65
Participant type
Healthy volunteer
Age group
Adult
Gender
Both
Target number of participants
Planned Sample Size: 20; UK Sample Size: 20
Participant exclusion criteria
Any gastrointestinal disease
Recruitment start date
01/08/2014
Recruitment end date
31/07/2015
Locations
Countries of recruitment
United Kingdom
Trial participating centre
NIHR/Wellcome Trust Imperial CRF
Imperial Centre for Translational and Experimental Medicine
Imperial College Healthcare NHS Trust
Hammersmith Hospital
Du Cane Road
London
W12 0HS
United Kingdom
Funders
Funder type
Research council
Funder name
Medical Research Council (MRC) (UK) - Clinical Trials Unit (CTU)
Alternative name(s)
MRC
Funding Body Type
government organisation
Funding Body Subtype
Federal/National Government
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journal within the next 6 months (by April 2018).
IPD sharing statement
The datasets generated and/or analysed during the current study during this study will be included in the subsequent results publication.
Intention to publish date
10/04/2018
Participant level data
Other
Basic results (scientific)
Publication list
1. 2018 results in: https://www.ncbi.nlm.nih.gov/pubmed/30015629