Whole Grain and Fiber Addition Study

Microbiome Stability After Addition of a High Fiber, Whole Grain and Bran Cereal to the Diets of Healthy Individuals

The human gut microbiota is the complex community of bacteria that reside within the human gastrointestinal tract. This community plays an important role in supporting normal immune function and digestion. Disruption of the microbial communities within the gastrointestinal tract, sometimes termed "dysbiosis" is linked to a wide range of human diseases, including obesity, metabolic syndrome, malnutrition, and cancer. Stability of the microbiome is thought to be important for human health, however the factors that drive microbiome community stability are poorly understood.

Within the gastrointestinal tract, the microbiota is constantly exposed to complex mixtures of foods and the products of digestion. Importantly, changes in diet have been shown to rapidly induce shifts in microbial community composition. These compositional shifts can also affect microbial production of bioactive metabolites, which may be one mechanism to explain how the microbiome impacts host physiology and disease.

Fiber is often considered to be one of the largest contributors to microbial compositional shifts that follow dietary interventions. Fiber resists digestion and persists through the gastrointestinal tract to reach the large intestine where it can be metabolized by bacteria. The end products of this metabolism are the short chain fatty acids (SCFAs), acetate and butyrate, which are often associated with beneficial health outcomes. Fibrous foods are also a source of polyphenols and other phenolic compounds that may be used by microbes in the production of secondary metabolites or freed from the food matrix by microbial enzymes.

The purpose of this study is to: 1) to investigate the impact of high fiber, whole grain and bran cereal on microbiome stability, and 2) to explore the microbial contribution to polyphenol metabolism from whole grain in healthy individuals.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: Fiber cereal

• Study Type: Interventional
• Enrollment (Actual): 29
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Minneapolis, Minnesota, United States, 55455
      • University of Minnesota

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Healthy adults over 18 years
• BMI between 18 and 30
• English speaker with ability to use a computer/smartphone.

Exclusion Criteria:

• Women who are currently pregnant or breastfeeding
• Current use of antibiotics or use of antibiotics within the last month
• Self-reported, pre-existing history of gastrointestinal disease including IBD, IBS, Crohn's disease, Celiac disease (or self-reported sensitivity to gluten), history of bowel blockage/impacted stool, fecal incontinence, gastroparesis or diverticulosis.
• Type I/II diabetes mellitus
• Participants actively trying to lose weight
• Chronic use of antacids and/or laxatives
• Use of seizure disorder medications or tricyclic antidepressants
• Consumption of drugs or supplements related to energy intake (i.e. diet pills and appetite suppressants)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Fiber Intervention I; Participants will be asked to consume two ½ cup servings of fiber cereal daily (equivalent to 28 g fiber) for 14 days, one in the morning and one in the evening.	Other: Fiber cereal; Whole grain and bran cereal
Experimental: Fiber Intervention II; Participants will be asked to consume two ¼ cup servings of fiber cereal daily (equivalent to 14 g fiber) for 14 days, one in the morning and one in the evening.	Other: Fiber cereal; Whole grain and bran cereal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in microbiome stability	Shotgun metagenomic sequencing of stool samples	Change from baseline to 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microbiome functional capacity	Assessment of microbiome functional capacity using DNA alignment to KEGG orthology	Baseline, 2 weeks, 6 weeks
Urinary metabolome	Targeted liquid chromatography mass spectroscopy to detect urinary metabolites	Baseline, 2 weeks, 6 weeks
Fecal short chain fatty acids	Targeted liquid chromatography mass spectroscopy	Baseline, 2 weeks, 6 weeks

Collaborators and Investigators

• Sponsor: University of Minnesota
• Collaborators: General Mills

Study record dates

Study Major Dates

• Study Start (Actual): May 4, 2018
• Primary Completion (Actual): March 1, 2019
• Study Completion (Actual): March 1, 2019

Study Registration Dates

• First Submitted: April 12, 2018
• First Submitted That Met QC Criteria: August 7, 2018
• First Posted (Actual): August 9, 2018

Study Record Updates

• Last Update Posted (Actual): November 1, 2019
• Last Update Submitted That Met QC Criteria: October 30, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: STUDY00002230

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: All IPD that underlie results in a publication.
• IPD Sharing Supporting Information Type: Study Protocol; Statistical Analysis Plan (SAP); Informed Consent Form (ICF); Clinical Study Report (CSR); Analytic Code

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No