The Effect of Increasing Dietary Protein on the Gut Microbiome and Its Metabolites (PSGM)

The Effect of Increasing Dietary Protein on the Gut Microbiota

This study will determine the effect of dietary protein not absorbed in the small intestine on the bacteria in the large intestine and the metabolites those bacteria produce when they break down the protein. The three specific goals are:

1. Determine if increasing dietary protein increases the purine breakdown product, allantoin, as observed in our previous study.
2. Establish a model to examine the effect of dietary protein on the gut microbiota and metabolites.
3. Identify gut bacteria and metabolite changes that occur with increased consumption of animal (whey) or plant (pea) protein sources.

Study Overview

• Status: Completed
• Conditions: Health Adults
• Intervention / Treatment: Other: Whey Protein; Other: Pea protein

Detailed Description

Healthy male and female participants were recruited following specific inclusion/exclusion criteria. Participants were excluded if they 1) were less than 25 years of age, 2) consumed pre or probiotics in the last week, 3) had taken any antibiotics in the last three months, 4) were taking any prescribed medicines for a chronic disease such as diabetes, hypertension, cancer, anxiety, depression, or GI-related diseases. and 4) had taken any laxatives or antidiarrhea inhibitors in the last week. The study design was pre/post, with each person serving as their own control. Interested participants were randomly assigned to one of two study groups: 50 g whey protein supplement or 50 g pea protein supplement. They were asked to consume the supplement along with their usual dietary intake. Participants were located within the contiguous USA and were sent a fecal collection kit, the protein supplement, and a shaker bottle using overnight shipping. We used the fecal collection kit developed by the Biocollective. A fecal sample was collected before and after the participant consumed the protein supplement daily for seven days. At both time points, the participants were asked to recall the foods they ate during the previous 24 hours using ASA24-2020, provide information on their physical activity (International Physical Activity Questionnaire, IPAQ), and answer questions about the stool sample they collected. The stool sample will be analyzed for the microbes and metabolites present. These will be correlated with the dietary protein they consume.

• Study Type: Interventional
• Enrollment (Actual): 87
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Louisiana
    • New Orleans, Louisiana, United States, 70112
      • Louisiana State University Health Sciences Center New Orleans

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 25 years old or older
• male or female
• located in the contiguous United States

Exclusion Criteria:

• Taken any prebiotics in the last week
• Taken any probiotics in the last week
• Taken any prescription medications other than oral contraceptives
• Taken antibiotics sometime in the last three months
• Taken any diarrhea inhibitors in the last week
• Taken any laxatives in the last week
• Taken any dietary supplement(s)
• Diagnosed with cancer
• Diagnosed with an inflammatory disease of the GI tract, such as irritable bowel disease
• Experienced long-haul COVID fatigue
• Were physically inactive (<600 METS per week)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Whey protein supplement; This group of participants will consume 50 g of whey protein supplement daily.	Other: Whey Protein; This intervention will add 50 g of a whey or pea protein supplement to their usual dietary intake.
Experimental: Pea protein supplement; This group of participants will consume 50 g of pea protein supplement daily.	Other: Pea protein; This intervention will add 50 g of a pea protein supplement to their usual dietary intake.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fecal allantoin	A cross-sectional study the investigators conducted found that healthy individuals who reported consuming, on average, 150 gms of protein daily had a higher fecal allantoin. This study is a pre/post-randomized controlled trial to confirm that observation. It will determine if consuming 50 gms more protein daily increases fecal allantoin.	A fecal sample is collected before and after consuming a protein supplement (pea or whey) for seven days.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in fecal bacterial species before and after increasing dietary protein intake (pea or whey) by 50 grams for seven days	The relative abundance of fecal bacterial species before and after consuming an additional 50 grams of pea or whey protein above the participant's usual dietary protein intake for seven days will be compared for each group to identify which species have significantly increased or decreased.	A fecal sample is collected before and after consuming a protein supplement (pea or whey) for seven days.
Changes in fecal metabolites before and after increasing dietary protein intake (pea or whey) by 50 grams for seven days	The intensity of fecal metabolites will be measured using mass spectrometry. The difference before and after consuming an additional 50 grams of pea or whey protein above the participant's usual dietary protein intake for seven days will be compared for each group to identify those metabolites that have significantly increased or decreased.	A fecal sample is collected before and after consuming a protein supplement (pea or whey) for seven days.

Collaborators and Investigators

• Sponsor: Louisiana State University Health Sciences Center in New Orleans
• Investigators: Principal Investigator: Lauri O. Byerley, PhD, APUS/LSUHSC

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2023
• Primary Completion (Actual): November 30, 2023
• Study Completion (Actual): November 30, 2023

Study Registration Dates

• First Submitted: November 4, 2024
• First Submitted That Met QC Criteria: November 5, 2024
• First Posted (Actual): November 6, 2024

Study Record Updates

• Last Update Posted (Actual): November 6, 2024
• Last Update Submitted That Met QC Criteria: November 5, 2024
• Last Verified: September 1, 2024

More Information

Terms related to this study

• Keywords: gut microbiome; gut microbiota; dietary protein; gut metabolites; gut metabolome; dietary purines
• Other Study ID Numbers: 5008

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data requests can be submitted six months after article publication. Qualified researchers engaged in independent scientific research can request access to this study's IPD, which will be provided following the review and approval of a research proposal, Statistical Analysis Plan (SAP), and execution of a Data Sharing Agreement (DSA). Data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis. For more information or to submit a request, please contact lbyerl@lsuhsc.edu.
• IPD Sharing Time Frame: Data requests can be submitted six months after article publication and will be accessible for up to 24 months.
• IPD Sharing Access Criteria: Qualified researchers engaged in independent scientific research can request access to this study's IPD, which will be provided following the review and approval of a research proposal, Statistical Analysis Plan (SAP), and execution of a Data Sharing Agreement (DSA). D
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No