Actively Recruiting
Dietary Fiber Effects on the Microbiome and Satiety
Led by University of Missouri-Columbia · Updated on 2025-06-22
88
Participants Needed
1
Research Sites
223 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Strong evidence supports the association between high fiber (HiFi) diets (e.g. legumes, nuts, vegetables) and a reduced risk for chronic conditions such as cardiovascular disease (CVD), type 2 diabetes and some forms of cancer. However, the current U.S. average consumption of dietary fiber of 17g/day is significantly below the recommendation level of 25g/d for women and 38g/d for men. Furthermore, fiber fermentation to produce short chain fatty acid (SCFA) products and alterations in microbial composition and activity may be mechanisms linking a HiFi diet to improved health. Importantly, much of the data, including findings supporting a beneficial role of SCFA have been derived from animal studies. Human studies are now needed to advance the understanding of the translational significance of rodent studies and the potential benefit of fiber on microbial metabolites and cardiometabolic health, glucose regulation, appetite and satiety. The central hypothesis is that that the mechanisms by which dietary fiber provides metabolic benefit include direct physical effects in the upper gastrointestinal tract to slow nutrient absorption, and indirect effects to reduce food intake mediated by SCFA-induced secretion of intestinal hormones resulting in increased satiety. Design: Using fiber derived from peas, Aim 1 will test the effect of a HiFi diet on appetite, satiety, and cardiometabolic health and whether elevated SCFA concentration mediates improved satiety in 44 overweight/obese subjects randomly assigned to receive either a high fiber or a low fiber dietary intervention for four weeks in a parallel arm-repeated measures design. Aim 2 will quantitate the changes in microbial composition and colonic SCFA production rate during HiFi feeding and whether any changes are potential mediators of observed benefits on satiety and cardiometabolic risk factors in 26 subjects assigned to receive a high fiber intervention for 3 weeks in a repeated measures design. Relevance: These studies will significantly expand the understanding of mechanisms by which dietary fiber improves satiety and cardiometabolic health in humans.
CONDITIONS
Official Title
Dietary Fiber Effects on the Microbiome and Satiety
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Men and premenopausal women
- Age 20 to 55 years for Aim 1; 45 to 55 years for Aim 2
- Body mass index (BMI) between 25 and 35 kg/m2 for Aim 1; between 25 and 40 kg/m2 for Aim 2
- Stable weight with less than 4 kg change in the last 3 months
- Willingness to follow a research diet
- Willingness to provide blood and fecal samples
- Presence of at least one metabolic syndrome characteristic such as large waistline (35 inches for women, 40 inches for men), high triglycerides (150 mg/dL or higher), low HDL cholesterol (<50 mg/dL for women, <40 mg/dL for men), high blood pressure (≥130/85 mmHg), or fasting blood sugar ≥100 mg/dL
- Pre-diabetes allowed with glucose less than 125 mg/dL or HbA1c less than 6.5%
- Stable use of statins, anti-hypertensives, or anti-depressants if they do not affect appetite, body weight, or the microbiome
You will not qualify if you...
- Pregnant or lactating women
- Postmenopausal women
- BMI less than 25 or greater than 35 kg/m2 for Aim 1; less than 25 or greater than 40 kg/m2 for Aim 2
- Use of medications that affect the gut microbiome such as antibiotics
- Use of medications known to affect appetite or gastrointestinal function (e.g., phentermine, metformin)
- Following a special diet or weight loss program, vegetarian, or other restricted dietary patterns
- Consuming more than 25 g/day or less than 10 g/day of fiber on average
- Drinking more than 1 alcoholic drink per day for women or more than 2 per day for men
- History of diseases like colon cancer, HIV, cardiovascular disease, or psychiatric disorders
- Use of tobacco products
- Having metal implants incompatible with MRI (Aim 1 only)
AI-Screening
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Trial Site Locations
Total: 1 location
1
University of Missouri-Columbia
Columbia, Missouri, United States, 65212
Actively Recruiting
Research Team
K
Katherene OB Anguah, PhD
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
PREVENTION
Number of Arms
2
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