The Effect of Grape Consumption on Increasing the Good Bacteria in the Human Intestine

Completed · Not applicable

Conditions studied: Healthy

In brief

This pilot study will assess the ability of daily consumption of one dose (2 servings) of freeze-dried whole table grape powder, made from conventionally grown grapes to alter the composition of the bacteria that live in the intestines in healthy subjects. The grape powder contains 46g of individually quick frozen (IQF) grapes, which is equivalent to 252g fresh fruit. 20 subjects will will consume the beige diet for 4 weeks followed by one dose (two servings) of standardized Freeze-Dried Whole Table Grape Powder (46g) daily for 4 weeks. The primary objective of this pilot study is to determine changes in the gut microbiome. Stool samples will be collected at 4 and 8 weeks for bacterial DNA to determine changes in the bacteria that live in the intestines. You will be asked to avoid foods rich in polyphenols including dark chocolate and cocoa products, dried herbs, berries, coffee, tea, flaxseeds, nuts (chestnut, hazelnut), olive and artichoke for the duration of the study.

Key facts

Study ID

NCT05025189

Run by

University of California, Los Angeles

People needed

20

Starts

2020-10-05

Expected to finish

2021-07-30

Last updated by the study team

2023-05-06

Who can join

Age: 18 and older, up to 55. Sex: any. Healthy volunteers: accepted.

You may qualify if…

• Healthy human adults age 18-55 years old (females have to be premenopausal)
• Typically consume low fiber/polyphenol diet (beige diet)

You may not qualify if…

• Eating a high fiber/polyphenol diet or taking any medication or dietary supplement, which interfere with the absorption of polyphenols.
• History of gastrointestinal surgery, diabetes mellitus on medications, or other serious medical condition, such as chronic hepatic or renal disease, bleeding disorder, congestive heart disease, chronic diarrhea disorders, myocardial infarction, coronary artery bypass graft, angioplasty within 6 months prior to screening, current diagnosis of uncontrolled hypertension (defined as systolic BP >160mmHg, diastolic BP > 95mmHg), active or chronic gastrointestinal disorders, bulimia, anorexia, laxative abuse, or endocrine diseases (except thyroid disease requiring medication) as indicated by medical history or routine physical examination.
• Screening laboratory value outside of the laboratory normal range that is considered clinically significant for study participation by the investigator.
• Is unable or unwilling to comply with the study protocol.
• Using prebiotics, probiotics, yogurt, and/or any fiber supplements regularly
• Allergy or sensitivity to grapes. Subjects will be excluded if there is a prior history of such sensitivity. Since these foods are commonly eaten and allergies are rare, subjects should be aware of this sensitivity prior to entering the study. To determine this, a positive affirmation by the subject of grape ingestion without incident will be requested.
• Taking antibiotics or laxatives within the past 3 months
• Allergy or sensitivity to grapes. Subjects will be excluded if there is a prior history of such sensitivity. Since these foods are commonly eaten and allergies are rare, subjects should be aware of this sensitivity prior to entering the study. To determine this, a positive history of grape ingestion without incident will be requested. In addition, any subject with a history of allergy or anaphylaxis of any kind will be excluded
• Subjects with known allergy to food coloring dyes.
• In the opinion of the study investigator, any subject who demonstrate a risk of non-compliance with study procedure, or one who cannot read, understand or complete study - related materials.

Where it is running

• UCLA Center for Human Nutrition — Los Angeles, California, United States

Full record on ClinicalTrials.gov

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