None listed
Conditions
Brief summary
Protein-rich animal foods (cooked meat, dairy) are highly digestible - our bodies are able to utilise nearly all of the protein consumed, whereas the protein digestibility of plant based food products can vary considerably. Given the growing interest in alternative non-animal based sources of protein, it is important to establish the protein digestibility of these new foods and protein concentrates which has important health implications especially for vulnerable groups who have difficulty in consuming enough dietary protein. The gold standard method for measuring protein digestibility is the human ileostomy model, as it enables protein digestion to be quantified independent of protein degradation in the large intestine. The use of animal models involving rats and pigs has been preferred for determining the digestibility of dietary proteins over using people with an ileostomy due to the availability of study participants. However, to minimise the use of animals in research, a standardised in vitro method, INFOGEST, has been developed to simulate the digestion process. This method has undergone considerable validation which has included direct comparisons with protein digestibility measurements in humans. A majority of this validation work has focused on highly digestible animal meat and dairy products and the European COST INFOGEST consortium have identified the important need to further validate the model using non-animal based protein foods. Aim: To use the ileostomy model to determine the protein digestibility of three plant proteins and to validate an in vitro model of protein digestion (INFOGEST). Primary objective is to compare plant protein digestibility data obtained from the ileostomy model with that obtained from the INFOGEST model. Secondary Objective is to determine the protein digestibility of wheat-based food containing alternative plant-based high protein flours. Hypotheses: H0: That plant protein digestibility as measured by the INFOGEST method does not correlate with protein digestibility data obtained from the ileostomy model. H1: That plant protein digestibility as measured by the INFOGEST method correlates with protein digestibility data obtained from the ileostomy model
Interventions
The pilot study will be designed as a randomised, double-blinded, controlled cross-over intervention. A total of 4 proctocolectomised adults with conventional and well-functioning permanent ileostomies will be recruited
The study will be conducted over 2 weeks within the participant’s home. This will comprise 4 testing days each week, for 2 weeks. On each testing day, they will consume 2 test muffins or protein-free biscuits in the morning (breakfast and morning tea) and a standardised lunch, af
The pilot study will be designed as a randomised, double-blinded, controlled cross-over intervention. A total of 4 proctocolectomised adults with conventional and well-functioning permanent ileostomies will be recruited The study will be conducted over 2 weeks within the participant’s home. This will comprise 4 testing days each week, for 2 weeks. On each testing day, they will consume 2 test muffins or protein-free biscuits in the morning (breakfast and morning tea) and a standardised lunch, afternoon tea and dinner will be provided. Each study participant will consume each test food (4 in total) on 2 consecutive days. The test foods are 3 different protein-containing muffins and a protein-free biscuit. The test muffins will be made using a muffin recipe using wheat flour and for 2 of the test muffins 50% of the flour will be substituted with soy or lupin flour. The order of the treatment will be randomly assigned across the 2-week testing period following a 4 X 4 Latin Square (4 possible sequences are ABCD, BCDA, CDAB and DABC). On each test day, participants will consume two test muffins or protein free biscuits in the morning (8am and 10am) and then collect ileostomy digesta over the 24 hr period following consumption of the first test muffin (8am to 8am). The digesta samples will be collected from the participant’s home by Research staff and analysed in the laboratory for analysis (protein and amino acid content). Participants will complete a daily log via a paper-based diary to assess protocol compliance, adverse events and use of concomitant medications. Any queries that arise from the surveys will be followed up by a phone call or email. The digestibility of the foods will be compared between the humans and in vitro digestibility (INFOGEST) using linear regression analysis. This will also allow us to confirm the suitability of the in vitro model for determination of the nutritional quality of protein sources. The INFOGEST model is an in vitro digestion method that involves the exposure of food samples to three successive digestive phases: oral, gastric and intestinal. It is a static digestion model, which uses a constant ratio of food to enzymes and electrolytes, and a constant pH for each digestive phase. To date, a majority of studies that have validated the utility of INFOGEST for studying protein digestibility have focused on highly digestible animal meat and dairy products, however data is limited regarding non-animal based protein foods.
Sponsors
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Study design
Allocation
Randomised controlled trial
Intervention model
Other
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
20 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. Adult male or female 2. Aged 20-80 years inclusive. 3. Health professional confirmation of minimal terminal ileum (up to 10 cm) removed more than 1 year ago and have a conventional and well-functioning permanent ileostomy deemed fit for the study intervention (confirmed by GP). 4. Understand the study requirements, including digesta collections and willing to adhere closely to consuming the prescribed food and drinks as per the research protocol.
Exclusion criteria
1. History of drug abuse or consumption of more than 14 serves alcohol/wk. 2. History of smoking within the 6 months prior to the study. 3. Participation in a dietary intervention study within 30 days of commencement of this study. 4. Use of any medication within the last 28 days that in the opinion of the investigator could interfere with the study or medications likely to modulate small intestinal function. 5. Definite or suspected personal history of adverse events or intolerance to foods made from wheat flour or soy or lupin or peanut 6. Currently taking protein supplements and not willing to stop using these during the study 7. Person considered by the investigator to be unwilling, unlikely or unable to comprehend or comply with the study protocol and restrictions. 8. Unwilling or unable to collect ileal effluent as required.
Outcome results
None listed