Effect of Prebiotic and PUFA on the Gut Microbiota and Metabolic Risk Markers

Study Overview
=================
Brief Summary
-----------------
The main objective of this study is to investigate in detail how a high-(prebiotic)fibre diet and a high-PUFA diet affect the gut microbiota composition in a metabolic challenged population, and if the diet-induced modulation of the gut microbiota mediates changes in metabolic risk markers. Intake of both experimental diets over 4 weeks are expected to induce beneficial changes in the gut microbiota composition and to affect markers for insulin sensitivity, lipid metabolism and inflammation. The investigators hypothesize that the effect of both interventions on the metabolic risk markers will be partly mediated by the diet-induced changes in the gut microbiota composition.

Official Title
-----------------
Effect of Prebiotic Fibre and Polyunsaturated Fatty Acid (PUFA) on the Gut Microbiota and Metabolic Risk Markers in a Metabolically Challenged Population

Conditions
-----------------
Overweight

Intervention / Treatment
-----------------
* Dietary Supplement: Wheat bran extract
* Dietary Supplement: Fish oil


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: BMI: 25-40 kg/m2 Non-smoking Indices of the Metabolic Syndrome defined by the International Diabetes Federation (IDF 2006): Central obesity (waist circumference; men: ≥94 cm and women: ≥80 cm) + any one of the following; raised triglyceride level (≥1.7 mmol/L), reduced HDL cholesterol (men: <1.03 mmol/L, women: <1.29 mmol/L), raised BP (systolic ≥130 mm Hg or diastolic ≥85 mm Hg) or raised fasting plasma glucose (≥5.6 mmol/L). Exclusion Criteria: Use of antibiotics Weight change >3 kg 2 months prior to study start Intensive physical training/ elite athlete Medication for dyslipidemia, type 2 diabetes or elevated blood pressure Dietary supplements with pro/prebiotics, dietary fibre or fish oil supplement Lactation, pregnancy or planning of pregnancy during the study Gastro intestinal and liver disorders Chronic inflammatory disorders Diagnosed psychiatric disorder including treatment required depression Surgical treatment of obesity and abdominal surgery

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 60 Years

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

Accepts Healthy Volunteers
-----------------
No

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

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High fibre diet (wheat bran extract)<br> | Dietary Supplement: Wheat bran extract<br>* Patients will be provided with 15g of wheat bran extract (WBE) (Cargill R&D Centre Europe).<br>|
| Experimental: High PUFA diet (fish oil supplement)<br> | Dietary Supplement: Fish oil<br>* Patients will be provided with a fish oil supplement (capsules), containing 3-4g of N-3 fatty acids (Axellus A/S, Ishøj, Denmark).<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in gut microbiota composition | Gut microbiota composition will be analyzed by use of fecal samples. | Week 0, 4, 8, 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in markers for insulin sensitivity | Will be measured by use of fasting blood samples | Week 0, 4, 8, 12 | 
| Change in markers for lipid metabolism | Will be measured by use of fasting blood samples | Week 0, 4, 8, 12 | 
| Change in markers for inflammation | Will be measured by use of fasting blood samples | Week 0, 4, 8, 12 | 
| Faecal SCFA and bile acid composition | Will be analyzed by use of fecal samples. | Week 0, 4, 8, 12 | 
| Lipidomics | Will be analyzed by use of fasting blood samples and fecal samples. | Week 0, 4, 8, 12 | 
| Metabolomics | Will be analyzed by use of fasting blood samples, urine and fecal samples. | Week 0, 4, 8, 12 |