Effects of Grape Consumption on the Immune-Gut Axis in Obesity

Effects of Grape Consumption on Immune and Gut Health in the Setting of Obesity

This study is investigating the benefits of whole freeze-dried grape powder consumption on the immune-gut axis in adults with obesity.

The study is a 12-wk randomized, controlled, crossover trial. Participants will be randomized to one of two intervention sequences, either consuming 48g/day of whole freeze-dried grape powder followed by an isocaloric placebo powder or consuming the placebo powder followed by the whole freeze-dried grape powder. Active intervention phases will be 4 weeks in duration followed by a 4-week washout period between treatments.

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