Plain English Summary
Background and study aims
Metabolic syndrome is a term used to describe a combination of factors which increase a person’s risk of heart disease and other health problems, such as diabetes and stroke. Many of these factors are linked with obesity, such as high blood pressure, cholesterol and body fat. Recent research has shown that there may be a link between the composition of different bacteria that live in the gut (gut microbiota) and the biological processes of disease. In a previous study, it was found that a Mediterranean diet, supplemented with nuts, led to a major reduction in disease risk factors. The aim of this study is to look at two different diets to find out what effect they have on the composition of bacteria in the gut and on metabolic risk factors.
Who can participate?
Men and women aged 30-65 who have three or more signs of metabolic syndrome
What does the study involve?
Participants are randomly allocated to consume two diets in a random order. Each of the diets lasts for eight weeks, and there is a four week period of consuming a normal diet in between them, to ensure the results of the different diets don’t influence each other. The first diet involves eating 50g of nuts every day in addition to regular diet. The second diet involves eating a Mediterranean diet, which involves high consumption of vegetables and olive oil and moderate consumption of protein. Before and after each dietary period, participants provide stool and blood samples which are then examined to assess the composition of bacteria living in the gut and to see if there has been any change to metabolic syndrome risk factors.
What are the possible benefits and risks of participating?
Participants may benefit from taking part due to the well founded benefits of consuming nuts and following a Mediterranean diet. There is a small risk of pain or bruising when blood samples are collected.
Where is the study run from?
1. Rovira i Virgili University (Spain)
2. Hospital Universitari Sant Joan (Spain)
When is the study starting and how long is it expected to run for?
January 2017 to December 2019
Who is funding the study?
Instituto de Salud Carlos III (Spain)
Who is the main contact?
Dr Mònica Bulló Bonet
monica.bullo@urv.cat
Trial website
Contact information
Type
Scientific
Primary contact
Dr Mònica Bulló Bonet
ORCID ID
http://orcid.org/0000-0002-0218-7046
Contact details
Unitat de Nutrició Humana
Universitat Rovira i Virgili (URV)
C/Sant Llorenç
21
Reus
43201
Spain
+34 977 75 93 13
monica.bullo@urv.cat
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
PI/00516
Study information
Scientific title
Effect of a diet on healthy food or a Mediterranean diet on change in the composition and function of faecal microbiota and its relationship with the metabolic improvement
Acronym
METADIET
Study hypothesis
The consumption of certain foods typical of the Mediterranean diet in the context of a non-Mediterranean diet will modify the composition and functionality of the intestinal microbiota towards a healthier profile.
Ethics approval
Ethics Committee (Hospital Universitari Sant Joan; Reus), 26/01/2017, Ref. CEIm: 04/2017
Study design
Randomised cross over trial
Primary study design
Interventional
Secondary study design
Randomised cross over trial
Trial setting
Hospitals
Trial type
Prevention
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Condition
Obesity and metabolic syndrome
Intervention
Participants are randomised to consume two dietary interventions in a random order. Each intervention period lasts for a total of eight weeks, with a four week wash out period between them.
Diet one: Participants consume their regular diet (RD) with the addition of 50g of nuts/day.
Diet two: Participants consume the Mediterranean diet. This consists of high consumption of vegetables and olive oil and moderate consumption of protein.
Participants will be followed up before and after each intervention period. Classic metabolic risk markers will be analyzed (glucose, lipid profile) as well as inflammation, oxidation and endothelial function markers by routine methods. The taxonomic composition in faeces will be determined as well as a quantitative metagenomic analysis in one sub-group. For the metabolomic analysis in plasma and faeces samples it will be use different analytic platforms according to the sample.
Intervention type
Behavioural
Phase
Drug names
Primary outcome measure
Metabolic risk markers are assessed by measuring glucose and lipid profile, inflammation, oxidation, and endothelial function markers by routine methods, ELISA and Luminex platform at baseline and 8 weeks in each intervention period.
Secondary outcome measures
Faecal microbiota is assessed through measuring the taxonomic composition in faeces (16S RNA) and quantitative metagenomic analysis at baseline and 8 weeks in each intervention period.
Overall trial start date
01/01/2017
Overall trial end date
31/12/2019
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Men and women
2. 30-60 years old - updated 17/10/2018: 30-65 years old
3. BMI≥25 and <35
4. ≥3 Metabolic Syndrome criteria:
4.1. Hypertension or hypertension treatment
4.2. Altered glycemia (≥100mg/dl)
4.3. HDL cholesterol (men<40mg/dl or women <50mg/dl)
4.4. Altered triglycerides (≥150mg/dl)
4.5. Abnormal waist circumference (men ≥ 102cm or women ≥ 88)
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
50 individuals
Participant exclusion criteria
1. BMI<25kg/m2 or BMI≥35
2. Type 2 diabetes
3. Secondary obesity or related pahologies
4. Non-controlled hypertension (Systolic arterial pressure (SAP)>159mmHg; Diastolic arterial pressure (DAP)>99mmHg)
5. LDL cholesterol >160mg/dl
6. Tryglicerides >400mg/dl
7. Mediterranean adscription punctuation ≥7 (PREDIMED trial)
8. Frequent nuts consumption (≥90g/week)
9. Frequent legumes consumption (≥120g/week)
10. Different chronic diseases (inflammatory, infectious, chronic obstructive pulmonary, neoplasias, endocrine, or hematological diseases)
11. Leucocytosis (leucocytes >11x10E9)
12.Pharmacological treatment (anti-inflammatory, corticoids, hormones or antibiotics)
13. Changes of diabetes, hypertension of lipidic profile medication (last 3 months).
14. Body weight loss (>5kg in the last 3 months).
15. Lost weight medication changes (last 3 months).
16. Breeding or pregnancy.
17. Diseases history (hepatic cirrhosis, intestinal inflammatory, intestinal resection).
18. Nuts or legumes allergy.
19. Probiotics, prebiotics or laxatives consumption
Recruitment start date
18/04/2017
Recruitment end date
15/09/2017
Locations
Countries of recruitment
Spain
Trial participating centre
Rovira i Virgili University (URV)
Human Nutrition Unit (Unitat de Nutrició Humana)
C/Sant Llorenç, 21
Reus
43201
Spain
Trial participating centre
Hospital Universitari Sant Joan
Av/del Dr. Josep Laporte, 2
Reus
43204
Spain
Sponsor information
Organisation
Instituto de Salud Carlos III
Sponsor details
St/Sinesio Delgado
4
28029 Madrid
Madrid
28029
Spain
+34 91 822 20 00
oficina.informacion@isciii.es
Sponsor type
Government
Website
Funders
Funder type
Government
Funder name
Instituto de Salud Carlos III
Alternative name(s)
Institute of Health Carlos III, Carlos III Health Institute, ISCIII
Funding Body Type
government organisation
Funding Body Subtype
Federal/National Government
Location
Spain
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journal.
IPD Sharing plan;
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Mònica Bulló Bonet (monica.bullo@urv.cat)
Intention to publish date
31/12/2019
Participant level data
Available on request
Basic results (scientific)
Publication list