Effect of Pea Fiber Supplementation on the Gut Microbiota and Host Metabolome and Proteome (FIB)

Washington University School of Medicine13 enrolled

Overview

All subjects will complete a 49-day, multi-phase feeding study to evaluate the effect of pea fiber supplementation on gut community structure and features of host biological state (plasma proteome/ metabolome). Subjects will be asked to continue to consume their habitual diet (free diet phase) for 4 days prior to being provided with a diet high in saturated fat (HiSF) and low in fruits and vegetables (LoFV) in the form of packed-out meals and snacks to consume for the following 45 days. Ten days after starting to consume the HiSF-LoFV diet, subjects will supplement their diet with pea fiber for a total of 21 days; the energy contribution from the HiSF-LoFV diet will be reduced accordingly to maintain energy needs during this time. After completing the pea fiber supplementation phase of the study subjects will revert back to consuming the HiSF-LoFV only diet for the final 14 days. Stool, urine and blood will be sampled periodically throughout.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Microbial Colonization

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 60 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * BMI 25.0-35.0 kg/m² * Presence of B. vulgatus and B. thetaiotaomicron each at greater than 0.01% relative abundance Exclusion Criteria: * Previous bariatric surgery * Significant organ system dysfunction (e.g. diabetes, severe pulmonary, kidney, liver, or cardiovascular disease) * Cancer or cancer that has been in remission for less than 5 years * Major psychiatric illness * Inflammatory gastrointestinal disease * Pregnant or lactating women * Use of medications that are known to affect the study outcome measures * Use of medications or supplements known to affect composition of the gut microbiota within the last 30 days (e.g. antibiotics) * Bowel movements less than 3 times per week * Vegans, vegetarians, and those with allergies, aversions, or sensitivities to foods provided in the study * Persons that are not able to grant voluntary informed consent * Persons who are unable or unwilling to follow the study protocol or who the research team deems not an appropriate candidate for the study.

Outcomes

Primary Outcomes

Change in plasma lipid profile as assessed by the complete metabolic panel and lipid panel.

Blood will be drawn for the complete metabolic panel and lipid panel

Time frame: At screening, day 14, day 35, and day 49

Changes to the gut microbiota as assessed by established culture independent methods, as well as LC-QTOF Mass-Spectometry (MS) and LC-QQQ MS and GC-MS

Frequent stool samples will be collected throughout the entire study

Time frame: stool samples will be collected from the screening visit through the final day of the 49-day intervention

Changes in urine proteomes and metabolomes as assessed by liquid chromatography

First morning urine samples will be collected periodically throughout the study

Time frame: Daily or every other day first-morning urine samples will be collected from day 1 to day 49 of the study

Changes in plasma proteomes and metabolomes as assessed by liquid chromatography

fasting blood draws will be collected periodically throughout the study

Time frame: Fasted blood draws will be collected on days 1, 14, 21, 28, 35, and 49 of the study

Change in hemoglobin A1c (HbA1c) in response to the dietary intervention

Blood will be drawn for the HbA1c