Influence of Freeze Dried Strawberry Consumption on Gut Microbiota and Cardiovascular Health.

Study Overview
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Brief Summary
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This proposal seeks to build upon studies, including ours, on the favorable effects of California strawberries on vascular health. Freeze dried strawberry powder (FDSP) contains a number of nutrients that may have beneficial effects on plasma lipids and vascular function, as well as on the composition of the gut microbiota; changes in the gut microbiota can in turn have secondary positive effects on the vascular system as well as on other physiological functions that are important determinants of health and disease. The proposed project will seek to determine the influence of short-term FDSP intake on the gut microbiota composition, and select microbial-derived metabolites from stool, serum and urine, and their relationship to microvascular function. Secondary outcomes will include the influence of the FDSP on circulating levels of nitrate and nitrite and trimethylamine oxide (TMAO) as markers of vascular health that are influenced by both dietary intake and the oral and gut microflora, with blood pressure as an additional vascular outcome.

Detailed Description
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A randomized, double-blind, controlled crossover design will compare the short-term (two and four week) response to FDSP intake compared to an isocaloric control powder in overweight and obese adults. Twenty overweight or obese male or postmenopausal females (40-65 years of age) will be randomized to consume 39 g of FDSP or a control powder for four weeks in a crossover design with a four week washout period. Changes in stool microbial communities and microbial metabolites will be assessed, and examined for their potential influence on microvascular function.

Official Title
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Probe Study Investigation on the Influence of Freeze Dried Strawberry Consumption on Gut Microbiota, Intestinal Health, Metabolic Phenotype and Cardiovascular Risk in Overweight and Obese Individuals.

Conditions
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Microbial Colonization, Cardiovascular Diseases, Obesity

Intervention / Treatment
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* Other: Freeze Dried Strawberry Powder
* Other: Isocaloric powder


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or postmenopausal female: 40-65 years Women: lack of menses for at least two years. Subject is willing and able to comply with the study protocols. Subject is willing to participate in all study procedures BMI 25.0 - 35 kg/m2 Exclusion Criteria: BMI ≥ 35 kg/m2 Dislike or allergy for strawberries or strawberry products Self-reported use of daily anticoagulation agents including aspirin, NSAIDs Vegan, Vegetarians, food faddists or those consuming a non-traditional diet Fruit consumption ≥ 2 cups/day Regular consumption of strawberries (2-3 cups/week) Vegetable consumption ≥ 3 cups/day for females Fatty Fish ≥ 3 times/week Coffee/tea ≥ 3 cups/day Dark chocolate ≥ 3 oz/day Self-reported restriction of physical activity due to a chronic health condition Self-reported chronic/routine high intensity exercise Self-reported diabetes Blood pressure ≥ 140/90 mm Hg Self-reported renal or liver disease Self-reported heart disease, which includes cardiovascular events and stroke Inability to properly place or wear the PAT probes or abnormal measurements on pre- screening PAT Abnormal Metabolic or CBC panels (laboratory values outside the reference range) if determined to be clinically significant by the study physician. Self-reported cancer within past 5 years Self-reported malabsorption Currently taking prescription drugs or supplements. Use of multi-vitamin and mineral other than a general formula of vitamins and minerals that meet the RDA Not willing to stop any supplement use, including herbal, plant or botanical, fish oil, oil supplements a month prior to study enrollment. Indications of substance or alcohol abuse within the last 3 years Screening LDL ≥ 190 mg/dl for those who have 0-1 major risk factors apart from LDL cholesterol (i.e. family history of premature coronary artery disease (male first degree relative < 55 years; CHD in female first degree relative < 65 years), cigarette smoker, HDL-C ≤ 40 mg/dL]. Screening LDL ≥ 160 mg/dl for those who have 2 major risk factors apart from LDL cholesterol [i.e. family history of premature coronary artery disease (male first degree relative < 55 years; CHD in female first degree relative < 65 years), cigarette smoker, HDL-C ≤ 40 mg/dL]. (using NCEP calculator http://cvdrisk.nhlbi.nih.gov/calculator.asp); Screening LDL ≥ 130 mg/dl for those who have 2 major risk factors apart from LDL cholesterol [i.e. family history of premature coronary artery disease (male first degree relative < 55 years; CHD in female first degree relative < 65 years), cigarette smoker, HDL-C ≤ 40 mg/dL], and a Framingham 10-year Risk Score 10-20% (using NCEP calculator http://cvdrisk.nhlbi.nih.gov/calculator.asp). Current enrollee in a clinical research study.

Ages Eligible for Study
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Minimum Age: 40 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: Randomized, double-blind, controlled crossover dietary intervention trial
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control Powder<br>Isocaloric powder | Other: Freeze Dried Strawberry Powder<br>* Study participants will be randomized to receive either the freeze dried strawberry powder or the control powder first. They will be instructed to consume 39g of the powder, mixed in water, every day for 4 weeks.<br>Other: Isocaloric powder<br>* Isocaloric powder<br>|
| Experimental: Freeze Dried Strawberry Powder<br>Contains freeze dried strawberries | Other: Freeze Dried Strawberry Powder<br>* Study participants will be randomized to receive either the freeze dried strawberry powder or the control powder first. They will be instructed to consume 39g of the powder, mixed in water, every day for 4 weeks.<br>Other: Isocaloric powder<br>* Isocaloric powder<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peripheral Arterial Tonometry (PAT) | microvascular function testing | 10 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gut Microbiome | assessment of gut microbial populations | 10 weeks | 
| Untargeted Metabolomics | assessment of primary metabolites | 10 weeks | 
| Plasma Cholesterol | plasma cholesterol | 10 weeks | 
| Plasma LDL | LDL | 10 weeks | 
| Plasma HDL | HDL | 10 weeks | 
| Nitrate | Circulating levels of Nitrate | 10 weeks | 
| Nitrite | Circulating levels of Nitrite | 10 weeks |