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Trial registered on ANZCTR


Registration number
ACTRN12622001227785
Ethics application status
Approved
Date submitted
4/08/2022
Date registered
12/09/2022
Date last updated
12/09/2022
Date data sharing statement initially provided
12/09/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
Comparison of protein quality of foods made from different plant sources
Scientific title
Evaluation of nutritional quality of plant proteins in human ileostomates
Secondary ID [1] 307522 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Protein digestion 326952 0
Condition category
Condition code
Oral and Gastrointestinal 324138 324138 0 0
Normal oral and gastrointestinal development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
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.
Intervention code [1] 323987 0
Treatment: Other
Comparator / control treatment
The digestibility of each food will be compared between the humans (gold standard method) and in vitro
Control group
Active

Outcomes
Primary outcome [1] 331954 0
True amino acid digestibility of the three different test muffins.
True protein/amino acid digestibility will be determined for the test muffins by calculating the amino acid content difference between the test meal and the ileal digesta contents and correcting this data using protein excretion data obtained following consumption of the protein free biscuit (measure of endogenous amino acid excretion). This provides an indication of the availability of the amino acids in the protein source.
Timepoint [1] 331954 0
Digesta will be collected through the ileostomies by the participants for a period of 10 hours after the test muffins have been consumed. They will empty their ostomy bags (collecting the contents every 2 hours during this 10-hour period and pooled sub-samples will over this time period will be analysed.
Secondary outcome [1] 411724 0
Total protein digestibility of the three different test muffins.
The proportion of the consumed protein that passes through the digestive tract (mouth to end of terminal ileum) over the 10-hour sampling period will be determined.
Timepoint [1] 411724 0
Digesta will be collected through the ileostomies by the participants for a period of 10 hours after the test muffins have been consumed. They will empty their ostomy bags (collecting the contents every 2 hours during this 10-hour period and pooled sub-samples, over this time period, will be analysed..

Eligibility
Key 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.
Minimum age
20 Years
Maximum age
80 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key 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.

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)
At screening, the applicant will be assigned a unique screening number in a sequential manner. This number will be used for screening only.
Following confirmation of eligibility and receipt of written consent, participants will be provided with a unique participant identifier for this study.
The random allocation sequence will be generated by the Clinic Manager who is not involved with entering participants into the trial to ensure allocation concealment.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will be randomly assigned by computer sequence generation (http://www.randomisation.com) to the order of the intervention condition; ABCD, DABC, CDAB or BCDA.
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
Other
Other design features
Incomplete Latin Square, with participants assigned randomly to the Latin Square.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Primary analyses will compare protein digestibility of the three different plant-proteins by ANOVA and a Tukey’s multiple comparison test.
The Digestible indispensable amino acid ratio (DIAAR) and Digestible indispensable amino acid score (DIAAS) will be calculated for data obtained from the in vitro (INFOGEST) and in vivo (ileostomy model) protocols (Sousa et al 2022, in press). The calculation will be made based on the digestibility of each individual indispensable amino acid, the amount of that amino acid in the food and the reference requirement values for that amino acid for preschool children (6 month to 3 years) given by the FAO (FAO, 2013).
Total protein digestibility, individual amino acid digestibility, DIAAR and DIAAS data obtained from the ileostomy model and INFOGEST will be compared by regression analysis. The threshold for significance will be set at 0.05 (two-sided). Statistical analyses will be performed using SPSS software (IBM Corporation, New York, USA).
Primary Outcomes: True amino acid digestibility
Secondary Outcomes: Total protein digestibility.

In a study of similar design (Rowan et al, 1994), ileal protein digestibility was 86.9 (SD 2.17) % when a range of protein containing foods (meat, vegetable, cereal and dairy) were consumed. A study based on a complete set of data from 3 volunteers will provide sufficient power (80%) to detect a 10% difference in ileal protein absorption.
Based on protein digestibility values published for the test flours proposed in the current study, the protein digestibility is calculated to be from 10-50% higher than wheat flour. Hence a change of 10% is a meaningful and realistic improvement to expect.
To allow for one person dropping out from the study a total of 4 people will be recruited.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
13/09/2022
Actual
Date of last participant enrolment
Anticipated
31/10/2022
Actual
Date of last data collection
Anticipated
23/12/2022
Actual
Sample size
Target
4
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
SA

Funding & Sponsors
Funding source category [1] 311802 0
Government body
Name [1] 311802 0
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Country [1] 311802 0
Australia
Primary sponsor type
Government body
Name
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Address
Gate 13 Kintore Ave, Adelaide, South Australia, 5000
Country
Australia
Secondary sponsor category [1] 313278 0
None
Name [1] 313278 0
Address [1] 313278 0
Country [1] 313278 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311246 0
CSIRO Health and Medical Human Ethics Committee
Ethics committee address [1] 311246 0
Gate 13 Kintore Ave, Adelaide, South Australia, 5000
Ethics committee country [1] 311246 0
Australia
Date submitted for ethics approval [1] 311246 0
29/03/2022
Approval date [1] 311246 0
09/09/2022
Ethics approval number [1] 311246 0

Summary
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
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 120442 0
Dr Damien Belobrajdic
Address 120442 0
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Gate 13 Kintore Ave, Adelaide, South Australia, 5000
Country 120442 0
Australia
Phone 120442 0
+61883038815
Fax 120442 0
Email 120442 0
damien.belobrajdic@csiro.au
Contact person for public queries
Name 120443 0
Dr Damien Belobrajdic
Address 120443 0
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Gate 13 Kintore Ave, Adelaide, South Australia, 5000
Country 120443 0
Australia
Phone 120443 0
+61 883038815
Fax 120443 0
Email 120443 0
damien.belobrajdic@csiro.au
Contact person for scientific queries
Name 120444 0
Dr Damien Belobrajdic
Address 120444 0
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Gate 13 Kintore Ave, Adelaide, South Australia, 5000
Country 120444 0
Australia
Phone 120444 0
+61 8 83038815
Fax 120444 0
Email 120444 0
damien.belobrajdic@csiro.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
To ensure confidentiality for the participants of this study.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.