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

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ClinicalTrials.gov Identifier: NCT05025189
Recruitment Status : Completed
First Posted : August 27, 2021
Last Update Posted : August 27, 2021
Sponsor:
Collaborator:
The California Table grape Commission
Information provided by (Responsible Party):
Zhaoping Li, University of California, Los Angeles

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Healthy Other: Table Grape Powder Other: Beige Diet Not Applicable

Detailed Description:
The bacterial composition of the intestinal microbiome has been linked to the development of chronic diseases including obesity, metabolic syndrome, type II diabetes and heart disease. Grapes provide a rich source of polyphenols and fiber. It has been demonstrated in animal studies that fruits with high polyphenol content and fiber exhibit prebiotic effects leading to changes in the gut microbiome, decrease in symptoms of metabolic syndrome, improvement in insulin resistance and decrease in intestinal and systemic inflammation. Several human intervention studies have also been performed that demonstrated beneficial effects of high polyphenol fruits on the intestinal microbiome. No information is available about the effect of grape consumption on the gut microbiome. This proposed pilot study will assess the ability of consumption of two servings of grapes daily to alter the gut microbiome composition, leading to increased bile secretion, increased fecal cholesterol degradation/excretion, decreased plasma cholesterol and improved intestinal wellbeing in a free-living population. 20 subjects 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. Secondary outcome will be fecal bile and cholesterol and their metabolites, plasma cholesterol and intestinal wellbeing questionnaire at 4 and 8 weeks Stool samples will be collected at 4 and 8 weeks for sequencing of bacterial DNA to determine changes in the microbiota. Changes in fecal bile, cholesterol, and cholesterol metabolites will be analyzed by gas chromatography. The objective of the proposed pilot study is to determine whether intake of 2 servings of grapes per day will alter the intestinal microflora leading to an increase in intestinal cholesterol degradation, decreased plasma cholesterol and increased intestinal wellbeing. This project will provide novel preliminary data for future research studies and to develop new consumer messages on the gut health benefits of grapes. New consumer information about the health benefit of grapes will enhance the The California Table Grape industry domestic and export marketing programs and increase consumption of grapes.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 20 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: This will be a two phase intervention study.
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Effect of Grape Consumption on the Microbiome in Healthy Subjects: A Pilot Study
Actual Study Start Date : October 5, 2020
Actual Primary Completion Date : March 6, 2021
Actual Study Completion Date : July 30, 2021

Arm Intervention/treatment
Active Comparator: Table Grape
Subjects will consume 4 weeks of (two servings) of standardized Freeze-Dried Whole Table Grape Powder
Other: Table Grape Powder
Freeze Dried Whole Table Grape Powder

Placebo Comparator: Beige Diet
Subjects will consume 4 weeks of a beige diet (low in fiber and low in polyphenols)
Other: Beige Diet
Low Fiber, low polyphenol Diet




Primary Outcome Measures :
  1. Change in intestinal microbiome composition [ Time Frame: Baseline (week 0) to Week 8 ]
    Stool samples will be collected at week 4 and 8 of the intervention periods


Secondary Outcome Measures :
  1. change in fecal cholesterol, cholesterol metabolites, and bile acids [ Time Frame: Baseline (week 0) to Week 8 ]
    Stool samples will be collected at week 4 and 8 of the intervention periods

  2. change in blood total cholesterol, LDL and HDL-cholesterol, [ Time Frame: Baseline (week 0) to Week 8 ]
    Total cholesterol in blood will be analyzed spectrophotometrically using cholesterol reagent

  3. digestive Health and General Wellness questionnaires (Rand SF-36) [ Time Frame: Baseline (week 0) to Week 8 ]
    The Weekly Digestive Symptom Log measures gastrointestinal symptoms (gas, bloating, diarrhea, etc.) and will be completed daily by all subjects. The Rand SF-36 will be completed at baseline (week 0), and week 4 visits to report on patients' overall well-being

  4. urine content of syringic acid, and ellagic acid metabolites - ellagic acid, and dimethylellagic acid glucuronide [ Time Frame: Baseline (week 0) to Week 8 ]
    as biomarkers for compliance



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Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

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

Exclusion Criteria:

  • 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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05025189


Locations
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United States, California
UCLA Center for Human Nutrition
Los Angeles, California, United States, 90024
Sponsors and Collaborators
University of California, Los Angeles
The California Table grape Commission
Investigators
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Principal Investigator: Zhaoping Li, MD, PhD UCLA Center for Human Nutrition
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Responsible Party: Zhaoping Li, Chief, Division of Clinical Nutrition, University of California, Los Angeles
ClinicalTrials.gov Identifier: NCT05025189    
Other Study ID Numbers: 18-001635
First Posted: August 27, 2021    Key Record Dates
Last Update Posted: August 27, 2021
Last Verified: August 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No