Prebiotic Effects of California Grapes on Gut Health and Cardiometabolic Health in Overweight Men and Women
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age45-70
SponsorUniversity of California, Davis
About this trial
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
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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
Disqualifiers
menopausal hormone replacement therapy started within less than 6 months
antibiotics, prebiotics within last 3 months
antidiabetic treatment involving insulin (for type 1 diabetes)
vegetarian/vegan and not able to follow modified diet
Trial design
Design model
Crossover
Treatments tested in this trial
Freeze-dried grape powder
Dietary supplement48 grams powder
Placebo powder
Other intervention48 grams powder
Treatment groups
40 Participants
are divided into 2 treatment groupsGroup A: Grape, Then PlaceboExperimental treatment 2 interventions
Group B: Placebo, Then GrapeExperimental treatment 2 interventions
Trial outcomes
Primary outcomes
1
Arterial stiffness Change from Baseline
Pulse Wave Velocity (PWV) from carotid to femoral artery after 5 minutes rest; PWV is an established index of aortic stiffness using a validated non-invasive device that allows online pulse wave recording and automatic PWV calculation
Time frame
Baseline (Visit 1), Week 3 (Visit 2), Week 9 (Visit 4)2
Blood pressure Change from Baseline
Average of latter 2 of 3 total measures (5 minutes apart) after 15 minutes of rest in a quiet room; SphygmoCor XCEL device will be used with participants in the seated position
Time frame
Baseline (Visit 1), Week 3 (Visit 2), Week 9 (Visit 4)3
Gut microbiome composition Change from Baseline
16S rRNA sequencing of stool samples collected by participants from home in fecal collection tubes filled with DNA/RNA shield
Time frame
Baseline (Visit 1), Week 3 (Visit 2), Week 9 (Visit 4)4
Gut permeability markers Change from Baseline
ELISA (zonulin, LPS, LBP, sCD14, DAO) to assay fasted blood samples collected when participants visit the clinic
Time frame
Baseline (Visit 1), Week 3 (Visit 2), Week 9 (Visit 4)Secondary outcomes
1
Gut permeability marker Change from Baseline
bacterial DNA presence in blood from fasted blood samples collected in tubes with DNA/RNA shield when participants visit the clinic
Time frame
Baseline (Visit 1), Week 3 (Visit 2), Week 9 (Visit 4)2
Metabolomics and Lipidomics Change from Baseline
Pathway Analysis using data available from analysis of blood samples collected when participants visit the clinic
Time frame
Baseline (Visit 1), Week 3 (Visit 2), Week 9 (Visit 4)3
Global gene expression Change from Baseline
Microarrays of blood samples collected when participants visit the clinic
Time frame
Baseline (Visit 1), Week 3 (Visit 2), Week 9 (Visit 4)Sponsors and contacts
Click on the lead sponsor to view all of their trials.
University of California, Davis
Lead sponsor
California Table Grape Commission
Collaborator
Source ClinicalTrials.gov