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Trial registered on ANZCTR


Registration number
ACTRN12622001212741
Ethics application status
Approved
Date submitted
24/08/2022
Date registered
8/09/2022
Date last updated
8/09/2022
Date data sharing statement initially provided
8/09/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
Gut Decisions: The impact of egg consumption on the gut microbiome, inflammation and brain cognition
Scientific title
The impact of daily egg consumption on the gut microbiome, inflammation and brain cognition in healthy adults
Secondary ID [1] 307835 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Disturbed gut microbial composition 327442 0
Impaired cognitive function 327443 0
Condition category
Condition code
Diet and Nutrition 324562 324562 0 0
Other diet and nutrition disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
180 adults will be recruited (90 aged 18-40, and 90 aged over 60). Each age group will be randomised into either the control group or intervention group. The intervention groups will be as follows:
1. 18-40 year old intervention group: required to eat 2 whole eggs a day for 6 weeks
2. Over 60 intervention group: required to eat 2 whole eggs a day for 6 weeks
There will be no restrictions on how the eggs are to be cooked and prepared for consumption.

Adherence will be monitored through weekly phone calls conducted by a researcher (an accredited practicing dietitian) as well as through three 3-day food records conducted at baseline, mid and end of study.
Intervention code [1] 324305 0
Treatment: Other
Comparator / control treatment
1. 18-40 year old control group: required to avoid eggs completely over 6 weeks
2. over 60 control group: required to avoid eggs completely over 6 weeks

Control participants will be provided with an information sheet about how to avoid eggs, including specifics on egg-containing foods that can be consumed or should be avoided. Generally speaking, foods with low egg content (such as cakes) are okay, but foods with high egg content (such as quiches or pavlovas) will need to be avoided. This resource will be designed by the researchers specifically for this study.

Adherence will be monitored through weekly phone calls conducted by a researcher (an accredited practicing dietitian) as well as through three 3-day food records conducted at baseline, mid and end of study.
Control group
Active

Outcomes
Primary outcome [1] 332396 0
Gut microbiota variety. Will be measured through DNA analysis of stool samples.
Timepoint [1] 332396 0
Stool samples taken at baseline (week 1), mid (week 3) and end of study (week 6)
Primary outcome [2] 332397 0
Brain cognition factor 1: interoception, Will be measured using the Schandry Paradigm (measures interoception, requires participants to measure their own heart rate)
Timepoint [2] 332397 0
Cognitive tasks will be conducted at the research facility at baseline (week 1) and end of study (week 6).
Primary outcome [3] 332461 0
Brain cognition factor 2: Decision-making. Will be measured using the Iowa Gambling task (measures decision-making, conducted as a short test on a computer)
Timepoint [3] 332461 0
Cognitive tasks will be conducted at the research facility at baseline (week 1) and end of study (week 6).
Secondary outcome [1] 413327 0
Inflammatory markers- cytokines and c-reactive protein. Measured via 12-hour fasting blood samples that will be taken at the research facility by a researcher who is trained in phlebotomy. Will be analysed using V-Plex pro-inflammatory panel 1 human kits.
Timepoint [1] 413327 0
Measured at pre (week 1), mid (week 3) and end of study (week 6).
Secondary outcome [2] 413328 0
Plasma choline levels will be measured via 12-hour fasting blood samples that will be taken at the research facility by a researcher who is trained in phlebotomy. Will be analysed using an INDIKO machine.
Timepoint [2] 413328 0
Measured at baseline (week 1), mid (week 3) and end of study (week 6).
Secondary outcome [3] 413329 0
Plasma Lipopolyssacharide -binding protein (LPD) will be measured via 12-hour fasting blood samples that will be taken at the research facility by the primary researcher who is trained in phlebotomy. Will be analysed using Hycult Biotech Human ELISA Kit.
Timepoint [3] 413329 0
Measured at baseline (week 1), mid (week 3) and end of study (week 6).
Secondary outcome [4] 413330 0
Dietary intake will be measured via 3-day food records at 3 timepoints throughout the study using the mobile phone app, Research Diet Diary created by Xyris. The information will be transferred to the Xyris Software, Foodworks to allow for analysis. This will measure average intake of energy, macronutrients and micronutrients.
Timepoint [4] 413330 0
Measured at baseline (week 1), mid (week 3) and end of study (week 6).
Secondary outcome [5] 413614 0
Plasma Trimethalyine N-Oxide (TMAO) levels will be measured via 12-hour fasting blood samples that will be taken at the research facility by a researcher who is trained in phlebotomy. Will be analysed using an INDIKO machine.
Timepoint [5] 413614 0
Measured at baseline (week 1), mid (week 3) and end of study (week 6).
Secondary outcome [6] 413615 0
(Primary outcome)- Brain cognition factor 3: Risk-taking. Measured using Balloon-Analogue Risk Test (measures risk-taking, conducted as a short test on a computer)
Timepoint [6] 413615 0
Cognitive tasks will be conducted at the research facility at baseline (week 1) and end of study (week 6).
Secondary outcome [7] 413616 0
(Primary outcome)- Brain cognition factor 4: Reaction time. Measured using Deary-Liewald Task (measures reaction-time, conducted as a short test on a computer)
Timepoint [7] 413616 0
Cognitive tasks will be conducted at the research facility at baseline (week 1) and end of study (week 6).

Eligibility
Key inclusion criteria
Participants will be female or male in a 1:1 ratio and will be within healthy or overweight BMI categories (BMI 18.5-29.9 kg/m2) and weight stable for the last two months (+/- 10%). No contraception intake.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
No antibiotics in the last 3 months. No history of neurological or psychiatric diseases. No history of diabetes mellitus, renal, hepatic, cardiovascular and respiratory diseases. No food allergy or chronic allergy (defined as requiring daily antihistamines). No use of pre- and/or probiotic supplements during the previous month. For the 18-40 year old participants, no menopause before the age of 40 years.

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
As there is no previous egg human microbiome cognition study, the sample size of n=45 per arm is based on Steenbergen et al., (2015) (a study that used a probiotic dietary intervention to modify gut microbiota and reduced cognitive reactivity to sad mood) using effect size: 0.158, alpha error: 0.05, Power: 0.80, 2 groups, 6 response variables, Critical F=2.6 Considering dropout rate and intervention duration, 10% (5 participants per arm) additional will be adequate.

Statistical analysis of data during the study will be conducted on the IBM SPSS Statistics Software. Statistical analysis will compare all outcomes between the treatment groups (eggs vs. no eggs) and between population groups (younger vs. older). Correlation between microbial abundance and other outcome measures will be performed. A variance-covariance model will assess for any treatment-by-population-by-time main or interaction effects for microbial abundance and decision-making response. Adjustment for changes in the baseline values of biomarker parameters and BMI will be performed by analysis of covariance (ANCOVA) using general linear models. If normal distribution is violated for the dependent variables under consideration, a linear mixed model will be used.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
28/11/2022
Actual
Date of last participant enrolment
Anticipated
30/10/2023
Actual
Date of last data collection
Anticipated
11/12/2023
Actual
Sample size
Target
180
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment postcode(s) [1] 38342 0
3168 - Clayton
Recruitment postcode(s) [2] 38343 0
3000 - Melbourne
Recruitment postcode(s) [3] 38344 0
3083 - Bundoora

Funding & Sponsors
Funding source category [1] 312110 0
Commercial sector/Industry
Name [1] 312110 0
Australian Eggs
Country [1] 312110 0
Australia
Primary sponsor type
Individual
Name
Dr Jessica Biesierkierski
Address
Monash University BASE Facility, 264 Ferntree Gully Rd.,
Notting Hill VIC 3168
Australia
Country
Australia
Secondary sponsor category [1] 313635 0
None
Name [1] 313635 0
Address [1] 313635 0
Country [1] 313635 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311512 0
Monash University Human Research Ethics Committee (MUHREC)
Ethics committee address [1] 311512 0
Monash University
Wellington Road
Clayton
Victoria 3800
Australia
Ethics committee country [1] 311512 0
Australia
Date submitted for ethics approval [1] 311512 0
10/08/2022
Approval date [1] 311512 0
15/08/2022
Ethics approval number [1] 311512 0
34637

Summary
Brief summary
Eggs provide an affordable, digestible and accessible source of many nutrients, including all eleven essential amino acids, vitamin A, E and B12, selenium, choline and iron, and unsaturated fatty acids including omega-3 (primarily DHA and ALA). Egg yolks are also
high in cholesterol and are a major source of dietary cholesterol in Australia. There are current gaps in the research supporting egg intake and other associated health effects outside of plasma cholesterol levels, across different populations and age groups.
Egg consumption microbiome studies in humans are extremely limited and have previously only focused on overweight postmenopausal women and/or effects on acute plasma choline levels and microbial taxa related to cardiovascular disease. The gut microbiome is thought to be a key component in Trimethylamine N-oxide (TMAO) metabolism, as trimethylamine is produced by gut bacteria from dietary choline, betaine, or L-carnitine, and then converted in the liver to TMAO, which in turn affects hepatic and intestinal lipid metabolism. Previous human studies have not shown egg consumption to affect plasma TMAO concentrations. However, inter-individual differences highlight the need for larger cohorts and more comprehensive assessment of the effects of egg consumption on gut microbiota.
The overall aim is to examine the human gut microbiome in response to egg consumption (compared to no egg consumption) and explore other clinical outcomes (i.e., cognition) and potential mediating factors (i.e., inflammation regulation) in younger and older adults.
Specifically, the aims are:
1. To assess effects of 6 weeks’ egg consumption on gut microbial composition and how consequent shifts in gut microbiome species and community function differ between age groups.
2. To explore how egg consumption may influence intuitive decision making, interoception, risk-taking and reaction-time
3. To explore how egg consumption may modulate intestinal immunity by altering levels of anti-inflammatory cytokines and other inflammatory markers such as C-reactive protein.
4. To explore the relationship between regular egg consumption, plasma choline, lipo-polysaccharide binding protein, and TMAO and how these levels may modulate or influence any of the above endpoints.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 121358 0
Dr Jessica Biesierkiersi
Address 121358 0
Monash BASE Facility, 264 Ferntree Gully Rd.
Notting Hill VIC 3168
Country 121358 0
Australia
Phone 121358 0
+61 3 9902 4269
Fax 121358 0
Email 121358 0
[email protected]
Contact person for public queries
Name 121359 0
Jessica Biesierkiersi
Address 121359 0
Monash BASE Facility, 264 Ferntree Gully Rd.
Notting Hill VIC 3168
Country 121359 0
Australia
Phone 121359 0
+61 3 9902 4269
Fax 121359 0
Email 121359 0
[email protected]
Contact person for scientific queries
Name 121360 0
Jessica Biesierkiersi
Address 121360 0
Monash BASE Facility, 264 Ferntree Gully Rd.
Notting Hill VIC 3168
Country 121360 0
Australia
Phone 121360 0
+61 3 9902 4269
Fax 121360 0
Email 121360 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Reasonable requests for access to the original de-identified data will be considered on a case-by-case basis by the Funding Body (Australian Eggs).
When will data be available (start and end dates)?
Data may be available up to 5 years after study completion (anticipated 2024).
Available to whom?
Reasonable requests for access to the original de-identified data will be considered on a case-by-case basis by the Funding Body (Australian Eggs).
Available for what types of analyses?
Reasonable requests for access to the original de-identified data will be considered on a case-by-case basis by the Funding Body (Australian Eggs).
How or where can data be obtained?
The funding body, Australian Eggs, can be contacted at [email protected] for any requests to access data.


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.