FIG: The Impact of Food on Gut Microbiome Composition - a Clinical Trial Determining the Influence of Diet in Gut Microbiome Colonisation and Host Health
Study Details
Study Description
Brief Summary
The goal of this clinical trial is to examine the impact of food derived bacteria on gut microbiome composition and host health. The main questions it aims to answer are:
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what is the the rate of gastrointestinal colonisation of food derived bacteria?
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what is the contribution of food derived bacteria to gut microbiome stability?
Participants will complete a cross over feeding study of dietitian designed meals of known microbial load and will be asked to provide stool and blood samples for analysis.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Early Phase 1 |
Detailed Description
To understand the role and stability of food derived bacteria in impacting microbiome composition, 20 healthy participants will be recruited for this single site double blinded randomised controlled crossover pilot trial. The study is divided into four 14 day diet phases - baseline habitual, specified diet 1, habitual washout and specified diet 2. Participants will be randomly assigned to receive a microbial or non-microbial diet in specified diet 1 phase. Each participant will then crossover to receive the alternative diet in the specified diet 2 phase. The microbial and non-microbial diets will be identical except for the removal of naturally occurring food derived bacteria in non-microbial diet. At the commencement of the study and at the end of each diet phase, participants will attend a research clinic to undergo comprehensive clinical and anthropometric assessment and dietary evaluation.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Specified Diet 1 - Microbial Diet Participants provided with a typical Australian diet including all food groups as described by the Australian Guide to Healthy Eating without any dietary exclusions. Meals have been designed by researchers and dietitians and prepared by professional chefs. |
Other: Diet
Participants will be assigned prospectively to microbial or non-microbial diet for first phase of trial and will then cross over to the alternate diet following a washout period.
|
| Active Comparator: Specified Diet 2 - Non-microbial Diet Diet provided to participants is identical to Specified Diet 1 however after cooking and packaging, food for this arm will be sterilised by irradiation in line with International Organisation for Standardisation (ISO) standards and Australian code of good manufacturing practice. |
Other: Diet
Participants will be assigned prospectively to microbial or non-microbial diet for first phase of trial and will then cross over to the alternate diet following a washout period.
|
Outcome Measures
Primary Outcome Measures
- Characterisation of gut microbiome [Day 1, 4, 7, 11 and 14 of each phase]
Sequencing and bacterial culturing of stool samples
Secondary Outcome Measures
- Participant body mass index (BMI) [BMI will be calculated on day 14 (at end of each diet phase (fortnightly))]
Assessed independently using height and weight measurements and appropriate formula
- Participant standing height [Height will be measured on day 14 (at end of each diet phase (fortnightly))]
Measured by stadiometer
- Participant weight [Weight will be measured on day 14 (at end of each diet phase (fortnightly))]
Measured using balance scales
- Participant waist circumference [Baseline day 1 and end of each 14-day diet phase]
Measured using standard measuring tape
- Participant Hip circumference [Baseline day 1 and end of each 14-day diet phase]
Measured using standard measuring tape
- Resting systolic and diastolic blood pressure [Blood pressure will be measured on day 14 (at end of each diet phase (fortnightly))]
Measured using digital blood pressure monitor
- Mental Health Assessment [Completed at day 1 and end of study (day 56)]
Perceived Stress Scale survey completed by participants
- Dietary compliance [Day 1 to Day 14 of specified diet 1 and diet 2 phases]
Measured by participant completed daily diet checklist noting the amount of food they consumed of provided meals during specific diet 1 and 2 phases
- Habitual dietary intake [Daily throughout 14-day baseline habitual and habitual washout phases]
Using research food diary mobile phone application
- Changes in physical activity levels [Completed at each of each 14-day diet phase]
Using International Physical Activity Questionnaire - Short Form (IPAQ-SF)
- Glucose levels [Blood collected at baseline day 1 and day 14 of each phase (fortnightly)]
Blood samples collected will be assessed for glucose levels
- Lipid studies [Blood collected at baseline day 1 and day 14 of each phase (fortnightly)]
Blood samples collected will be assessed for lipid studies
- Irritable Bowel Syndrome-Severity Scoring System (IBS-SS) [End of each 14-day diet phase]
Completion of Irritable Bowel Syndrome-Severity Scoring System (IBS-SS)
- Gastrointestinal symptomatology [Baseline day 1 and day 14 of each diet phase (fortnightly)]
Completion of Gastrointestinal Symptom Rating Scale (GSRS)
- Bowel movement [Baseline day 1 and day 14 of each diet phase (fortnightly)]
Completion of Bristol Stool Chart questionnaires
- End of study optional semi-structured interview [End of study (at least 8 weeks post-randomisation)]
Interview participants to assess challenges of adhering to study and compliance
Eligibility Criteria
Criteria
Inclusion Criteria:
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Have no genetic conditions (e.g. Prader Willi or Down's Syndrome)
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Not diagnosed with a significant medical conditions (e.g. irritable bowel syndrome, inflammatory bowel disease or type 1/2 diabetes)
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Do not require drug-therapy (e.g. steroids or insulin or antibiotics)
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Not taking dietary supplements, probiotics, prebiotics, symbiotics or fibre supplementation
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Any condition that will affect participation in the study
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Not pregnant, planning a pregnancy or breastfeeding
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Able to complete a two-month dietary study and agree to eating all meals provided
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Have no dietary allergies or dietary restrictions that prevent consumption of provided study meals
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Open bowels regularly - mostly daily
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Able to read, write and understand English
Exclusion Criteria:
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Dietary concerns identified by dietitian
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Aged less than 18 years and older than 65 years
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Diagnosed with a medical condition that requires drug therapy
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Taking medications or supplements known to alter gastrointestinal microbiota
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Women who are pregnant, planning a pregnancy or breastfeeding
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Anyone with a diagnosed gastrointestinal condition/disease e.g. irritable bowel syndrome or inflammatory bowel disease
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Known dietary allergy and/or intolerance, follows a vegan or vegetarian diet, or has coeliac disease
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Anyone with a preference for specific food avoidance or exclusion of certain ingredients in habitual diet
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Unable to tolerate blood collection procedures
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Unable to provide regular stool samples throughout the study
Contacts and Locations
Locations
No locations specified.Sponsors and Collaborators
- Monash University
Investigators
- Principal Investigator: Dr. Sam Forster, Hudson Institue, Monash University
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- RES-21-0000-602A