Effect of Fat Quality on Glycemic Regulation and Gut Microbiota After a Short-time Intervention in Healthy Individuals

Study Overview
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Brief Summary
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The overall aim is to investigate effects of saturated versus polyunsaturated fat on glycemic regulation and satiety in a postprandial study with healthy individuals. The potential effects will be related to changes in gut microbiota, the circulating levels of short chain fatty acids, inflammation and gene expression in peripheral mononuclear blood cells.

Detailed Description
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The intervention study will have a randomized, double blinded, cross-over design with different test meals consisting of saturated or polyunsaturated fat. The amount of fat will be identical in the test meals, but the fat quality will vary. The test meals are in the form of muffin and spread. All participants will consume two muffins and minimum 20 g of spread a day for three consecutive days, consisting of either a high proportion of saturated fat or a high proportion of polyunsaturated fat. At day one (visit 1 and 3) and day four (visit 2 and 4) of the intervention week, the participants will perform a postprandial glucose test (OGTT, 75 g glucose in 100 ml water) at Oslo Metropolitan University. Blood samples will be taken before and at different time points after the glucose test. One week prior to the intervention week and during wash-out (11 days), the participants will consume the control products which are high in saturated fat. At the screening visit (visit 0) the participants will be asked to limit the intake of dietary fat and fiber from oat and barley one week prior to visit 1 and during the study. Otherwise, participants will be asked not to change their diet and exercise habits during the study period. Individuals fulfilling the inclusion criteria will also be invited to participate in a cross-sectional study for investigating the gut microbiota in a healthy population. An OGTT will be performed at visit 1, 2, 3 and 4. The participants will receive test meals after screening and before visit 1, 2, and 3.

Official Title
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Fat Quality and Blood Glucose

Conditions
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Postprandial Blood Glucose, Gut Microbiota, Satiety

Intervention / Treatment
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* Other: Saturated fat 14.9 E%
* Other: Polyunsaturated fat 13.6 E%


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI between 18,5 and 27 kg/m2 Fasting plasma glucose ≤ 6.1 mmol/l Exclusion Criteria: Chronic metabolic diseases such as diabetes type 1 and 2, coronary heart disease and cancer the last 6 months. Intestinal diseases such as chron's disease, ulcerative colitis and irritable bowel syndrome. Food allergy and intolerances towards grain and dairy products. Pregnant and lactating Smokers Fasting blood glucose ≥ 6.1 mmol/L BMI <18,5 and >27 kg/m2 Planned weight reduction and or ± 5% weight change over the past three months. Use of antibiotics last 3 months before study entry and during the study period Use of probiotics the last month before study entry and during the study period Blood donor last 2 months before study entry and or during the study period Not willing to end the use of dietary supplements, including probiotic products, fish oil etc. four weeks prior to study entry and throughout the study period Alcohol consumption > 40g / day Hormone treatments (except contraceptives)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Intervention with cross-over design. Two test meals will be tested.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Test meal 1: Saturated fat 14.9 E%<br>Test meal with saturated fat 14.9 E% | Other: Saturated fat 14.9 E%<br>* Dietary cross-over study with saturated fat<br>|
| Experimental: Test meal 2: Polyunsaturated fat 13.6 E%<br>Test meal with polyunsaturated fat 13,6 E% | Other: Polyunsaturated fat 13.6 E%<br>* Dietary cross-over study with polyunsaturated fat<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood glucose response measured in capillary blood | Blood glucose response after oral glucose tolerance test (OGTT) measured in Finger-prick capillary blood samples | Change from baseline at day 4 | 
| Serum Insulin response measured in venous blood samples | Serum Insulin response after OGTT measured in venous blood samples | Change from baseline at day 4 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hydrogen breath response measured in expired air | Hydrogen breath response after OGTT measured in expired air by Gastroanalyzer | Change from baseline at day 4 | 
| Free fatty acids | Plasma free fatty acids are measured after intake of test meals | Change from baseline at day 4 | 
| Microbiota analyses in feces | Microbiota analyses in feces are measured before and after intake of test meals. Change in microbiota will be analysed | Change from baseline at day 4 | 
| Serum triglyceride response | Triglyceride response are measured are measured after OGTT | Change from baseline at day 4 | 
| Serum cholesterol | Serum cholesterol are measured fasting after intake of test meals | Change from baseline at day 4 | 
| Hunger and satiety hormones (e.g. GLP2, PYY) | The response in hunger and satiety hormones after OGTT | Change from baseline at day 4 | 
| Inflammatory markers (e.g. CRP) | Response in Inflammatory markers are measured after OGTT | Change from baseline at day 4 | 
| mRNA analyses in PBMC | PBMC are collected before and after OGTT. The change in mRNA level will be analyzed | Change from baseline at day 4 | 
| Quantitative assessment of metabolites in urine | Morning urine are collected before and after intake of test meals. Metabolites in urine will be quantified using UHPLC-qTOF-MS. Change in metabolites before and after test meals will be analyzed | Change from baseline at day 4 | 
| Quantitative assessment of metabolites in plasma | Plasma for metabolome analyses are collected after intake of test meals. Metabolites in plasma will be quantified using UHPLC-qTOF-MS | Change from baseline at day 4 | 
| Visual analogue scale (VAS) | Subjective hunger and satiety after OGTT and will be measured on a 100 mm horizontal line. Marks towards right end on line indicates strong sensation for hunger and satiety, whereas marks towards left end indicates opposite sensation. The distance from left border of line to the mark indicates subjective sensation. | Change from baseline at day 4 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fat quality, Blood glucose, Gut microbiota, Satiety, Dietary intervention