Dietary Fiber Effects on the Microbiome and Satiety

Conditions

• Dietary Fiber

Eligibility Criteria

Sex

ALL

Age

20 Years - 55 Years

Healthy Volunteers

Accepted

Interventions

• Dietary fiber: 10-25g — OTHER
  10-25 g/day of fiber
• Dietary fiber: 5g — OTHER
  5 g/day of fiber

Study Details

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.

Key Dates

Start date

Apr 22, 2021

Status verified

Jun 2025

Primary completion

Aug 1, 2025

Completion

Aug 1, 2025

Study Design

Enrollment

88 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

PREVENTION

Arms

• Experimental: High Fiber diet
  Group receiving a high fiber diet
• Other: Low Fiber diet
  Control group receiving a low fiber diet

Primary Outcome Measure

Change in microbiome composition and diversity [ Time Frame: Aim 1: On day 1, on 3 separate days during the intervention and on day 28 of the high fiber or low fiber intervention; Aim 2: within 14 days of scheduled colonoscopy visit and on 7 separate days during the intervention ]

Central Contacts

• Katherene OB Anguah, PhD
  (573)-882-8966
  [email protected]

Locations (1)

Find similar trials in Columbia, MO

Related Studies

• Aimmune Longitudinal Collaboration Study
  Recruiting · Aimmune Therapeutics, Inc. · Ambler, Pennsylvania