Variability in Microbial Response to Dietary Fiber

NCT06023940 | Completed

• 1 other identifier: 2053546
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to understand varying in responses to different dietary patterns in healthy people who are getting a health screening colonoscopy. The main questions it aims to answer are:

• What is the variability in the change of the microbes in the gut of (1) a provided diet that is high in fiber vs (2) a diet of the participant's choice.
• What is the magnitude of fasting changes in glucose and lipids following the short-term, high-fiber feeding period and identify candidate predictive factors (short-chain fatty acids, BMI, sex, starting glucose level) for these changes Participants will be in one of two groups:
• High-fiber diet group: These participants will have a series of measurements that include: blood biochemistries, body composition measured via DEXA, anthropometrics, surveys and questionnaires, and collection of fecal samples.
• Normal diet group: These participants will eat a diet that is of their choosing (ad libitum) and will have a series of measurements that include: fecal samples, and questionnaires/surveys including food records.

Conditions

Microbial Colonization

Keywords

colonoscopy; fiber

Outcome Measures

Primary Outcomes (2)

• Variability in microbial composition as measured by 'alpha diversity'

  Measured via fecal sample. Intervention group - measured once before scheduled health screening colonoscopy and 2 times over 2 weeks post-colonoscopy (day 1, 7, 14). Control group - measured once before scheduled health screening colonoscopy and 5 days over 2 weeks post-colonoscopy (day 3, 5, 8, 11, 14). Variability in microbial composition refers to how many different kinds of microbes are present in the fecal sample. We are testing the possibility that the more kinds of microbes, the healthier the person. The higher the measure the alpha diversity, the greater the number of different microbes.

  2 weeks

• Concentration of SCFA

  Measured via fecal sample. Intervention group - measured once before scheduled health screening colonoscopy and 2 times over 2 weeks post-colonoscopy (day 1, 7, 14). Control group - measured once before scheduled health screening colonoscopy and 5 days over 2 weeks post-colonoscopy (day 3, 5, 8, 11, 14).

  2 weeks

Secondary Outcomes (2)

• Blood glucose concentration (mg/dL)

  2 weeks

• Blood lipid concentation (total cholesterol, LDLc, HDLc) (mg/dL)

  2 weeks

Study Arms (2)

High Fiber

EXPERIMENTAL

Subjects are provided a high-fiber diet for 2 weeks. Tests include: blood biochemistries, body composition measured via DEXA, fecal sample collection, and anthropometrics measured

Dietary Supplement: High fiber

Control

NO INTERVENTION

Subjects are not provided any diet, instead they eat what they choose for two weeks while they participate in a series of tests including: fecal sampling, food records, questionnaires/surveys, and anthropometrics

Interventions

High fiber DIETARY_SUPPLEMENT

A pea fiber supplement is added to a diet of regular foods. Participants receive 25g fiber daily.

High Fiber

Eligibility Criteria

• Age: 45 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Men and women
• Age 45-65y: the average age of people referred for a screening colonoscopy
• BMI ≥20.0 or ≤40.0 kg/m2
• Weight stable: no fluctuations in body weight of greater than 4 kg in the last 3 months
• Scheduled for a health-screening colonoscopy
• Willingness to consume a high-fiber diet
• Willing to provide blood and fecal samples
• Healthy or have one or more characteristics of the metabolic syndrome (but not diabetic) Metabolic syndrome criteria
• A large waistline: 35 inches or more for women 40 inches or more for men
• High triglycerides: 150 mg/dL or higher
• Low HDLc level: \<50 mg/dL for women \<40 mg/dL for men
• High blood pressure ≥130/85 mmHg
• Fasting blood sugar ≥100 mg/dL - Pre-diabetes acceptable (glucose \<125 mg/dL or HbA1c \<6.5%)
• Subjects are also eligible if they are stably treated with statin drugs, anti-hypertensive medications, and anti-depressants. These are eligible as long as the drug category does not alter appetite, body weight, or the microbiome (if known).

You may not qualify if:

• Pregnant or lactating, or planning to become pregnant
• BMI of \<20.0 or \>40.0 kg/m2
• Use of tobacco products
• Uncontrolled hypertension and blood pressure ≥ 180/110
• Use of medications that affect the gut microbiome (e.g., antibiotics)
• Taking medications known to affect appetite (phentermine) or gastrointestinal function (e.g. metformin)
• On a special diet vegetarian, or other restricted dietary patterns
• Undergoing weight loss
• Ad libitum intake of fiber above 25 g/day (mean intake in the US population is 17 g/day) and also an intake of fiber \<10 g/d
• Ad libitum alcohol intake of greater than 7 drinks/week for women and 14 drinks/week for men
• History of disease (example colon cancer, etc.)
• Live more than 45 miles away from the University because participants will need to come into the Lab every 3 days or so to pick up meals.
• Men and women
• Age 45-65y: the average age of people referred for a screening colonoscopy
• Scheduled for a health-screening colonoscopy

Sponsors & Collaborators

• University of Missouri-Columbia: lead

Study Sites (1)

University of Missouri

Columbia, Missouri, 65212, United States

Location

MeSH Terms

Conditions

Communicable Diseases

Condition Hierarchy (Ancestors)

Infections; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Elizabeth Parks

  University of Missouri-Columbia

  PRINCIPAL INVESTIGATOR

• Yezaz Ghouri, MD

  University of Missouri-Columbia

  PRINCIPAL INVESTIGATOR

• Katherene Anguah, PhD

  University of Missouri-Columbia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor, Nutrition & Exercise Physiology-MED

Model Details: Treatment group: 2 week high fiber diet Control group: no diet provided, subjects eat whatever they want

Study Record Dates

• First Submitted: May 4, 2023
• First Posted: September 5, 2023
• Study Start: May 12, 2022
• Primary Completion: October 31, 2023
• Study Completion: October 31, 2023
• Last Updated: July 24, 2024

Record last verified: 2024-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)