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

Healthy Clinical Trial

Official title: Effect of Grape Consumption on the Microbiome in Healthy Subjects: A Pilot Study

Status Completed

Clinical Trial 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.

Clinical Trial 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. ;

Related Conditions & MeSH terms

• Healthy

• NCT number: NCT05025189
• Study type: Interventional
• Source: University of California, Los Angeles
• Status: Completed
• Phase: N/A
• Start date: October 5, 2020
• Completion date: July 30, 2021