Inflammation, Metabolic Syndrome X
Conditions
Keywords
flavonoids, insulin resistance, plasma lipids, intestinal microbiome, intestinal inflammation, subclinical inflammation
Brief summary
The investigators have hypothesized that dietary flavonoids reduce insulin resistance and subclinical inflammation secondary to reductions in intestinal inflammation and permeability and that these events are mediated through alterations in gut microbiota composition. To test this hypothesis, 30 overweight/obese men and women will be provided two well-controlled diets that are identical in macronutrient content (Protein, 17% en; Fat, 30% en; Carbohydrate, 53% en), but differ markedly in flavonoid content (Low Flavonoid Diet, 10 mg/1000 Kcals; High Flavonoid Diet, 340 mg/1000 Kcals). All meals for both diets will be prepared and fed for 6 weeks each in a randomized cross-over design with endpoints determined in duplicate during the last week of each diet period.
Interventions
OTHERHigh Dietary Flavonoids
A prepared diet consisting of whole foods with a macronutrient composition of 17% en from protein, 30% en from fat and 53% energy from carbohydrate and containing high levels of dietary flavonoids including anthocyanins, flavanones, flavan-3-ols, flavonols, flavones, and polyflavonoids.
OTHERLow Dietary Flavonoids
A prepared diet consisting of whole foods with a macronutrient composition of 17% en from protein, 30% en from fat and 53% energy from carbohydrate and containing low levels of dietary flavonoids including anthocyanins, flavanones, flavan-3-ols, flavonols, flavones, and polyflavonoids.
Sponsors
Utah State University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* BMI between 25 and 35 kg/m2
Exclusion criteria
* Documented presence of atherosclerotic disease; * Diabetes mellitus * Uncontrolled hypertension * Renal, hepatic, endocrine, gastrointestinal or other systemic disease * For women, pregnancy, breast feeding or postpartum \< 6 months * History of drug or alcohol abuse * History of depression or mental illness requiring hospitalization within the last 12 months * Use of antibiotics within the last 6 months * Multiple food allergies or significant food preferences or restrictions that would interfere with diet adherence * Chronic use of over-the-counter medication which would interfere with study endpoints including NSAIDS, laxatives and antacids * Lifestyle or schedule incompatible with the study protocol * Other medical, psychiatric, or behavioral conditions that in the view of the principal investigator may present a safety hazard to the participant or interfere with study participation or the ability to follow the intervention protocol.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Serum C-reactive protein | 6 weeks | One of two primary endpoints for systemic inflammation |
| Fecal calprotectin | 6 weeks | Primary endpoint for intestinal inflammation |
| Serum insulin | 6 weeks | Primary endpoint for insulin resistance |
| Serum soluble tumor necrosis factor receptor-1 | 6 weeks | One of two primary endpoints for systemic inflammation |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fecal myeloperoxidase | 6 weeks | Secondary endpoint for intestinal inflammation |
| Intestinal permeability by four sugar differential absorption test | 6 weeks | Secondary endpoint for intestinal inflammation |
| Serum endotoxin | 6 weeks | Secondary endpoint for intestinal inflammation |
| Serum interleukin-6 | 6 weeks | Secondary endpoint for systemic inflammation |
| Fecal microbiome composition | 6 weeks | Includes relative abundances of operational taxonomic units and assigned taxonomy as well as alpha and beta diversity measurements |
| Fecal short chain fatty acids | 6 weeks | Measure of fecal microbiome metabolic capabilities and includes acetate, propionate, butyrate, valerate and caproate. |
| Fecal eosinophil protein X | 6 weeks | Secondary endpoint for intestinal inflammation |
| Serum fasting glucose | 6 weeks | Secondary endpoint for insulin resistance |
| Calculated Homeostatic Model Assessment-Insulin Resistance | 6 weeks | Secondary endpoint for insulin resistance |
| Serum C-peptide | 6 weeks | Secondary endpoint for insulin resistance |
| Plasma lipids | 6 weeks | Secondary endpoint for insulin resistance. Includes LDL-cholesterol, HDL-cholesterol and triglycerides |
| Blood pressure | 6 weeks | Secondary endpoint for insulin resistance. Includes systolic and diastolic blood pressure |
| Serum soluble tumor necrosis factor receptor-2 | 6 weeks | Secondary endpoint for systemic inflammation |
Other
| Measure | Time frame | Description |
|---|---|---|
| Serum resistin | 6 weeks | Measure of adipocyte inflammation and systemic metabolism |
| Serum adiponectin | 6 weeks | Measure of adipocyte inflammation and systemic metabolism |
| Serum visfatin | 6 weeks | Measure of adipocyte inflammation and systemic metabolism |
| Body weight | 6 weeks | — |
| Serum leptin | 6 weeks | Measure of adipocyte inflammation and systemic metabolism |
Countries
United States
Outcome results
None listed