The Impact of Dietary Flavanols on the Gut Microflora

Not Applicable

Completed

• Conditions: Intestinal Bacteria Growth
• Interventions: Dietary Supplement: Low flavanol cocoa beverage; Dietary Supplement: High flavanol cocoa beverage

• Registration Number: NCT01091922
• Lead Sponsor: University of Reading

Brief Summary

The primary propose of this study is to determine the impact of flavanol-rich cocoa on the growth of the human gut microbiota.

Detailed Description

A randomised, placebo-controlled, double-blind, cross-over human intervention study will be conducted in 20 healthy human volunteers to test the impact of a high-flavanol containing meal on the growth of the large intestinal bacteria (microflora). The high flavanol test meal will contain 495 mg of flavanols and the low flavanol control will contain 23 mg of flavanols. The two intervention diets are otherwise matched for macro- and micronutrient content. Changes in the gut microbiota will be determined by measuring bacterial population levels in human faecal material using 16S rRNA targeted oligonucleotide probes and fluorescence in situ hybridization. A number of other biochemical and physiological measures will be recorded including blood glucose, lipoproteins, cytokine levels and blood pressure.

Study Timeline

• Study Start: 2008-01
• Status Verified: 2008-03
• Primary Completion: 2009-12
• Study Completion: 2009-12
• Study First Submitted: 2010-03-23
• Study First Submitted QC: 2010-03-23
• Last Update Submitted: 2010-03-23
• Study First Posted: 2010-03-24
• Last Update Posted: 2010-03-24

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 22

Inclusion Criteria

• a signed consent form
• age of 18-50 years inclusive
• BMI between 20-26

Exclusion Criteria

• pregnant or lactating
• allergy to milk products
• sensitivity to alkaloids and/or caffeine
• gastrointestinal disorders (e.g., chronic constipation, diarrhoea, inflammatory bowel disease, -inflammatory bowel syndrome, or other chronic gastrointestinal complaints)
• diabetes mellitus
• hypertension (>150/90 mm/Hg)
• anaemia and gall bladder problems
• not consuming probiotics, prebiotics, antibiotics or anti-inflammatory or blood lowering medication within a 2-month period prior to the study.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Low Flavanol	Low flavanol cocoa beverage	Low flavanol drink containing 23 mg of total flavanols. Macro- and micro-nutrient matched with active comparator
High Flavanols	High flavanol cocoa beverage	High Flavanol drink containing 495 mg of total flavanols

Primary Outcome Measures

Name	Time	Method
Faecal bacteria numbers using 16S rRNA targeted oligonucleotide probes analysis and fluorescence in situ hybridization	baseline and 4 weeks	Measurements of the growth rate and number of bacterial species in human faecal samples using 16S rRNA targeted oligonucleotide probes and fluorescence in situ hybridisation.

Secondary Outcome Measures

Name	Time	Method
Blood pressure	Baseline, 4 weeks

Trial Locations

Locations (1)

University of Reading; 🇬🇧 Reading, Berkshire, United Kingdom