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

Not Applicable

Completed

Brief Summary: 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.

Recruitment & Eligibility

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.

Arm && Interventions

Group	Intervention	Description
Diet intervention	Low fiber diet	All participants will stay weight stable while undergoing 3 phases of a dietary intervention
Diet intervention	Pea Fiber Bar	All participants will stay weight stable while undergoing 3 phases of a dietary intervention

Primary Outcome Measures

Name	Time	Method
Changes in urine proteomes and metabolomes as assessed by liquid chromatography	Daily or every other day first-morning urine samples will be collected from day 1 to day 49 of the study	First morning urine samples will be collected periodically throughout the study
Changes in plasma proteomes and metabolomes as assessed by liquid chromatography	Fasted blood draws will be collected on days 1, 14, 21, 28, 35, and 49 of the study	fasting blood draws will be collected periodically throughout the study
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	stool samples will be collected from the screening visit through the final day of the 49-day intervention	Frequent stool samples will be collected throughout the entire study
Change in plasma lipid profile as assessed by the complete metabolic panel and lipid panel.	At screening, day 14, day 35, and day 49	Blood will be drawn for the complete metabolic panel and lipid panel
Change in hemoglobin A1c (HbA1c) in response to the dietary intervention	At screening, day 14, day 35, and day 49	Blood will be drawn for the HbA1c

Secondary Outcome Measures

Name	Time	Method

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