Grape powder effects on gut and immune health in adults with obesity
Official title: Effects of Grape Consumption on Immune and Gut Health in the Setting of Obesity
Run by University of Missouri-Columbia · NCT07231484 · Data updated 2026-11-12
This 12-week test will see if taking 48 g per day of freeze-dried grape powder changes the gut microbiome and immune markers in adults aged 30–45 with obesity.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years to 60 Years |
| Sex | All |
| Enrollment | 50 (estimated) |
| Sponsor | University of Missouri-Columbia Academic / other |
| Locations | 1 site (Columbia, Missouri) |
| Status | Recruiting |
| Started | December 19, 2025 |
| Main results expected | December 20, 2027 |
| Study ends | December 30, 2027 |
| Registry record updated | July 31, 2026 |
| Trial ID | NCT07231484 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates are adults aged 30–45 with BMI 30–45 kg/m2 who are weight-stable, non-smokers, not recently using antibiotics or immune-modifying medications, and willing to consume the study foods and attend in-person visits.
✕Probably not a fit
People with diabetes, active gastrointestinal disease, recent antibiotic/probiotic use, pregnancy or lactation, HIV, or current use of immune- or metabolism-altering medications are unlikely to benefit or be eligible.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This is a 12-week randomized, controlled crossover design in which each participant receives both the grape powder and an isocaloric placebo in different periods. Participants are randomized to consume 48 g/day of whole freeze-dried grape powder for 4 weeks followed by a 4-week washout and 4 weeks of placebo, or the placebo first followed by the grape powder. Stool, blood, and clinical measures will be collected to measure changes in the gut microbiome and immune-related markers. The trial enrolls weight-stable adults aged 30–45 with BMI 30–45 kg/m2 at the University of Missouri–Columbia.
Why it matters
Potential benefit: If successful, the grape powder could offer a simple dietary approach to improve gut microbiome balance and immune-related markers in people with obesity.
How similar studies have gone: Previous animal studies and small human trials of grape polyphenols and other fruit-derived phytochemicals have shown changes in the microbiome or immune markers, but results in people with obesity are limited and mixed.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age: 18-60 years * Obesity with BMI of 30-45 kg/m2 * Willingness to consume study foods * Consistent diet and activity patterns for 4 weeks * Weight stable (\<5kg change over last 3 months) * Non-smoker \> 1 year or more * Not currently consuming an extremely healthy diet Exclusion Criteria: * Study food allergies * Regular consumption of grapes or grape-derived products * Gastrointestinal disease and/or bariatric surgery * Uncontrolled hypertension and blood pressure \>180/110 * Diabetes * Illicit drug use * History of alcohol or drug abuse * Recent use of medications that affect immune function (e.g., corticosteroids) * Recent consumption of antibiotics, prebiotics, probiotics, symbiotics, or dietary supplements containing fiber or phytochemicals * Pregnant or lactating individuals * HIV positivity * Recent start of medications that affect metabolism or appetite * Drug therapy for coronary artery disease, peripheral artery disease, congestive
Where it's running
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University of Missouri-Columbia
Columbia, Missouri, United States Recruiting
Study contacts
- Study coordinator: Jaapna Dhillon PhD, PhD
- Email: jdhillon@health.missouri.edu
- Phone: 573-884-2103
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.