Effects of Blueberry on Gut Microbiota and Metabolic Syndrome

Study Overview
=================
Brief Summary
-----------------
There is growing evidence that nutritional intervention with dietary polyphenols can positively modulate the gut microbiota to improve cardiometabolic health. Whether the beneficial effects of blueberries on obesity and the metabolic syndrome can be linked to their potential impact on the gut microbiota and intestinal integrity remains speculative at this time. Moreover, the mechanisms of action underlying health benefits associated to blueberry consumption are still unknown. The investigators are thus proposing to combine the study of metagenomics, transcriptomics and metabolomics to test whether a prebiotic activity of highbush blueberries can play a role in the prevention of obesity-linked metabolic syndrome in a clinical setting.

Official Title
-----------------
Prebiotic Effects of Blueberry in Overweight/Obese Individuals: Potential Role of the Gut Microbiota in Alleviating the Metabolic Syndrome.

Conditions
-----------------
Gut Microbiota, Metabolic Syndrome

Intervention / Treatment
-----------------
* Dietary Supplement: 50 g of blueberry powder, taken daily for 8 weeks
* Dietary Supplement: 50g of placebo blueberry powder, taken daily for 8 weeks


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Men and premenopause women in good health Caucasians At least one of the following : BMI between 25 and 40 kg/m2 or Waist circumference ≥ 80 cm for women and ≥ 94 cm for men At least one of the following : TG ≥ 1.35 mmol/L or fasting insulinemia ≥ 42 pmol/L Exclusion Criteria: Metabolic disorders (hypertension, diabetes, hypercholesterolemia) Regular use of medication affecting study parameters Use of natural health product in the last 3 months Use of antibiotics in the last 3 months Nicotine users Allergy or intolerance for blueberries Blueberry taste aversion More than 2 alcohol drinks par day Particular dietary habits (vegetarism, gluten-free diet, cetogenic diet...) Weight change of more than 5% in the last 3 months Surgery in the last 3 months or planed during the study

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Blueberry powder<br> | Dietary Supplement: 50 g of blueberry powder, taken daily for 8 weeks<br>* Subjects will consume blueberry powder during 8 weeks to test the possible effects of blueberries on gut microbiota composition and on metabolic syndrome parameters.<br>|
| Placebo Comparator: Blueberry placebo powder<br> | Dietary Supplement: 50g of placebo blueberry powder, taken daily for 8 weeks<br>* Subjects will consume blueberry placebo powder to test if there is a significant difference on the impact on gut microbiota composition and metabolic syndrome parameters between this treatment and the active treatment (blueberry powder).<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in plasma insulin/glucose of overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 12 months | 
| Changes in plasma lipids/lipoproteins of overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in gene expression in overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 3-6 months | 
| Changes in metabolites concentration in overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 3-6 months | 
| Changes in the gut microbiota composition in overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 3-6 months | 
| Changes in blood pressure of overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 12 months | 
| Changes in intestinal integrity of overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 12 months | 
| Changes in inflammation biomarkers of overweight/obese men and women taking either blueberry powder or placebo blueberry powder |  | 12 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Blueberry, Diet