Assessing Prebiotic Effect of California Grape Consumption on Gut Microbiome and Impact on Intestinal Permeability, Vascular Function, and Systemic Inflammation in Over-weight Subjects: Differences in Effects Between Men and Women
University of California, Davis
Summary
The goal of this clinical trial is to assess the impact of table grape consumption on gut microbiome, intestinal permeability, systemic inflammation, and vascular function in healthy overweight men and women aged 45-70 years. The main questions it aims to answer are: * Does daily grape intake alter intestinal microbiome composition and intestinal permeability? * Are changes in gut microbiota and intestinal permeability correlated with changes in cardiometabolic risk factors (inflammation, vascular function, lipid profiles)? * Does response to grape intake on gut microbiota, intestinal permeability, cardiometabolic and inflammatory markers differ between men and women? * Are metabolic pathways modified by grape consumption able to explain the link between gut health and cardiometabolic factors? Researchers will compare freeze-dried grape powder to placebo powder to see if grape powder improves cardiometabolic risk factors. Participants will * Consume the powder dissolved in water twice daily for 3 weeks * Follow their usual diet, modified to limit polyphenol-rich foods * Visit the clinic at the beginning and end of the intervention for vascular measurements and blood sample collection * Complete a 3-day 24-hour dietary recall and collect stool sample before each visit
Description
Participants will limit intake of grapes and other polyphenol-rich foods while following their usual diet during the 1-week run-in period before the start of the intervention. They will be randomized to start with either grape or placebo powder for 3 weeks, consuming 48 grams of freeze-dried grape powder or placebo dissolved in water twice daily. Compliance will be assessed with three 24-hour dietary recalls using ASA24 and follow-up contact. After a 3- to 4-week washout period, participants will crossover to the other intervention. Study outcomes and anthropometry will be measured on the firs…
Eligibility
- Age range
- 45–70 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * post-menopausal women (cessation of menstruation for minimum two years) * overweight and obese (BMI between 25-35 kg/m2) * stable treatment for type 2 diabetes or metabolic syndrome * ability to understand the intervention concept and written consent to participate * willingness to accept randomization, undergo testing and intervention procedures, and deliver stool and blood samples Exclusion Criteria: * menopausal hormone replacement therapy started within less than 6 months * antibiotics, prebiotics within last 3 months * antidiabetic treatment involving insulin (for…
Interventions
- Dietary SupplementFreeze-dried grape powder
48 grams powder
- OtherPlacebo powder
48 grams powder
Location
- Ragle Human Nutrition CenterDavis, California