Red Raspberry Polyphenols on Gut Microbiome — RRB2  

Healthy Subjects Clinical Trial

Official title: The Reciprocal Interactions Between Red Raspberry Polyphenols and Gut Microbiome Composition Affect Insulin Sensitivity

Status Completed

Clinical Trial Summary

The primary objective aims are to assess the effects of regular consumption of red raspberries (RRB) with and without fructooligosaccharide (FOS) on the composition of the gut microbiota after 4 week intake and in parallel characterize plasma and urine metabolite profiles examining qualitative and quantitative intervention associated changes.

Clinical Trial Description

The study will be performed as a single-blinded, randomized, crossover manner. Thirty subjects (20 insulin resistant subjects and 10 healthy subjects) will be randomly assigned into one of two sequences: sequence A (n=15) will be RRB then RRB+FOS (which means subject will consume only RRB (125 g/day(d) (equivalent to 1 cup fresh RRB)) with breakfast for 4 weeks, and then after a 4-week washout period, that subject will consume the RRB with FOS (125 g/d RRB and 8 g/d FOS) for 4 weeks); sequence B (n=15) will be RRB+FOS then RRB (which means subject will receive the RRB with FOS for 4 weeks, a 4-week washout, and then the RRB for another 4-week). At the beginning and end of each 4-week treatment, subjects will undergo a 6-h Study Day (4 study days in 12-week study duration) followed by a 1-h next morning follow-up visit.

Subjects will be required to meet several inclusion and exclusion criteria, which will be assessed through online survey and on-site clinic assessments, including questionnaires, blood analysis and anthropometric measures. Eligible subjects will be invited to participate in the study. Each subject will be asked to come for 1 Screening Visit, 4 dinner pick-ups (the day before each Study Day), 4 Study Days and 6 Weekly Meetings.

During the Screening Visit, subjects will read, sign and date a written Institutional Review Board approved Informed Consent Form prior to performing any study procedure. And then they will be assessed their qualification, instructed on the process for completing study questionnaires and counseled to restrict intake of colored plant foods rich in phytonutrients the 3 days prior to each Study Day. They will be asked to restrict alcohol intake, coffee/tea/ caffeinated beverage intake and moderate / vigorous physical activity and to drink plenty of water to maintain hydration in the 24 h prior to each Study Day. They will be instructed to come to the Clinical Nutrition Research Center (CNRC) the day before each Study Day to pick up their dinner meal and evening snack. Subjects will be asked to get at least 7 hours sleep and to come to the CNRC after a 10-h overnight fasting on each Study Day.

Each Study Day will require subjects to be in the clinic for ~7 h to complete all baseline and post challenge beverage testing procedures, including a 6 h study day and a 1 h next morning follow-up visit. Subjects will be evaluated for compliance with the protocol (diet, exercise, sleep, fasting), have their body weight and blood pressure measured, ingest a cup of red raspberry drink (250 g RRB (equivalent to 2 cups fresh RRB) and 64 g glucose) and their blood, urine and feces samples will be collected. ;

Related Conditions & MeSH terms

• Glucose Intolerance
• Healthy Subjects
• Pre-diabetes
• Prediabetic State

• NCT number: NCT03049631
• Study type: Interventional
• Source: Clinical Nutrition Research Center, Illinois Institute of Technology
• Status: Completed
• Phase: N/A
• Start date: May 18, 2017
• Completion date: July 6, 2020