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Trial registered on ANZCTR


Registration number
ACTRN12621000487819
Ethics application status
Approved
Date submitted
26/03/2021
Date registered
27/04/2021
Date last updated
28/03/2022
Date data sharing statement initially provided
27/04/2021
Type of registration
Prospectively registered

Titles & IDs
Public title
Dietary Intake: Associations with mood and non-communicable disease
Scientific title
Assessing the association between habitual process-modified protein intake and the ratio of urinary tryptophan metabolites, tryptamine and 5-hydroxyindoleacetic acid, in the general public.
Secondary ID [1] 303773 0
None
Universal Trial Number (UTN)
None
Trial acronym
DIAMOND study
Linked study record
None

Health condition
Health condition(s) or problem(s) studied:
depression 321274 0
anxiety 321275 0
gut microbiota function 321276 0
Condition category
Condition code
Diet and Nutrition 319047 319047 0 0
Other diet and nutrition disorders
Mental Health 319048 319048 0 0
Depression
Mental Health 319049 319049 0 0
Anxiety
Metabolic and Endocrine 319451 319451 0 0
Normal metabolism and endocrine development and function

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Participant dietary intake of process-modified protein is the exposure of interest. This will be assessed using a 4-day food diary to assess participants' usual food intake. Participants will complete the food diary at eating occasions over the course of four days prior to attending their study visit. It is estimated that participants will spend approximately 2 hours completing the food diary over the course of 4 days. Levels of process-modified protein consumed will be calculated using food composition tables and the NOVA classification system for processed foods.
Participants will attend a single study testing visit at which they will provide a fasting urine (mid-stream, first-void) sample and blood sample (approx. 30 mL). Participants will also complete surveys in relation to their demographics, physical activity level (International Physical Activity Questionnaire (IPAQ)) and mood (Centre for Epidemiological Studies Depression scale (CES-D) and Spielberger State Trait Anxiety Inventory (STAI)). It is estimated that it will take participants approximately 40 minutes to complete these surveys.
Intervention code [1] 320083 0
Not applicable
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 326954 0
The primary outcome is the ratio of tryptamine to 5-hydroxyindoleacetic acid, as measured in urine via liquid chromatography and mass spectrometry.
Timepoint [1] 326954 0
Single time point of data collection (cross-sectional)
Secondary outcome [1] 393270 0
Score on the Center for Epidemiologic Studies Depression Scale (CES-D).
Timepoint [1] 393270 0
Single time point of data collection (cross-sectional)
Secondary outcome [2] 393271 0
Score on the Spielberger State Trait Anxiety Scale (STAI).
Timepoint [2] 393271 0
Single time point of data collection (cross-sectional)
Secondary outcome [3] 393272 0
Exploratory metabolomics analysis of plasma looking to identify amino-acid related metabolites.
Timepoint [3] 393272 0
Single time point of data collection (cross-sectional)
Secondary outcome [4] 393273 0
Fasting plasma glucose concentration, measured on an Indiko Analyser.
Timepoint [4] 393273 0
Single time point of data collection (cross-sectional)
Secondary outcome [5] 393274 0
Fasting plasma insulin concentration, measured by ELISA.
Timepoint [5] 393274 0
Single time point of data collection (cross-sectional)
Secondary outcome [6] 393275 0
Fasting serum cholesterol (total, HDL and LDL) concentration, measured on an Indiko Analyser.
Timepoint [6] 393275 0
Single time point of data collection (cross-sectional)
Secondary outcome [7] 393276 0
Fasting serum triglyceride concentration, measured on an Indiko Analyser.
Timepoint [7] 393276 0
Single time point of data collection (cross-sectional)

Eligibility
Key inclusion criteria
Body mass index between 18.5 and 35 kg/m2
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Diagnosed with an inflammatory bowel disease (e.g. Ulcerative colitis, Crohn’s disease)
Any dramatic dietary changes in the past 3 months (e.g. becoming vegetarian, starting a restrictive diet)
Taking anti-depressant or anti-anxiety medication
Pregnant or breastfeeding

Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Convenience sample
Timing
Both
Statistical methods / analysis
Based on alpha = 0.05, a power of 80% and an estimated correlation coefficient of 0.20 between dietary process-modified protein intake and ratio of urinary tryptophan metabolites, 194 participants will be required to demonstrate a statistically significant result.

Regression analysis will be used to assess associations between estimated process-modified protein intake and dependent variables.

Recruitment
Recruitment status
Withdrawn
Reason for early stopping/withdrawal
Lack of funding/staff/facilities
Date of first participant enrolment
Anticipated
24/05/2021
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
194
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 308176 0
University
Name [1] 308176 0
Monash University
Country [1] 308176 0
Australia
Primary sponsor type
Individual
Name
Prof Louise Bennett
Address
School of Chemistry, Faculty of Science, Monash University
Room 318, 13 Rainforest Walk, Clayton, Victoria, 3800, Australia
Country
Australia
Secondary sponsor category [1] 308954 0
None
Name [1] 308954 0
None
Address [1] 308954 0
None
Country [1] 308954 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 308161 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 308161 0
Wellington Rd, Melbourne, Victoria 3168, Australia
Ethics committee country [1] 308161 0
Australia
Date submitted for ethics approval [1] 308161 0
24/03/2021
Approval date [1] 308161 0
13/04/2021
Ethics approval number [1] 308161 0
23731

Summary
Brief summary
This study will help us learn about how diet, specifically processed-modified protein intake, influences factors related to the health of our gut bacteria and the risk of mood disorders such as depression and anxiety.

When we consume high amounts process-modified proteins, these processed proteins may not be digested and used via the normal pathways, but fermented by the gut bacteria, producing various other biologically active compounds. The altered digestion and metabolism of these proteins may be linked with mood disorders, such as depression and anxiety, as a result of altered serotonin production. The researchers will assess how protein is being used in the body through assessing metabolites in blood and urine samples, and assess risk of depression and anxiety using questionnaires, to find out how these are influenced by dietary intake of processed-modified proteins.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 109750 0
Prof Louise Bennett
Address 109750 0
School of Chemistry, Faculty of Science, Monash University
Room 318, 13 Rainforest Walk, Clayton, Victoria, 3800, Australia
Country 109750 0
Australia
Phone 109750 0
+61 3 9905 6136
Fax 109750 0
Email 109750 0
[email protected]
Contact person for public queries
Name 109751 0
Margaret Murray
Address 109751 0
School of Chemistry, Faculty of Science, Monash University
Room 218, 13 Rainforest Walk, Clayton, Victoria, 3800, Australia
Country 109751 0
Australia
Phone 109751 0
+61 3 9905 1415
Fax 109751 0
Email 109751 0
[email protected]
Contact person for scientific queries
Name 109752 0
Louise Bennett
Address 109752 0
School of Chemistry, Faculty of Science, Monash University
Room 318, 13 Rainforest Walk, Clayton, Victoria, 3800, Australia
Country 109752 0
Australia
Phone 109752 0
+61 3 9905 6136
Fax 109752 0
Email 109752 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
The raw data will not be shared in a data repository, registry or open source platform because it will all be made available via publications/thesis in grouped de-identified form.


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.