Garden-fresh Foods and Gut Microbiomes (GFF)

Microbiomes of Garden-fresh vs Store-bought Produce and Variation in Their Effects on the Human Gut Microbiome

The purpose of this research is to explore what types of microbes are present on garden-fresh versus store-bought fruits and vegetables, as well as how they might affect the human gut microbiome.

Study Overview

• Status: Recruiting
• Conditions: Gut Microbiome
• Intervention / Treatment: Other: Garden-fresh Produce; Other: Supermarket Produce

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Gwynne Mhuireach, PhD; Phone Number: 541-346-4694; Email: gwynhwyf@uoregon.edu

Study Locations

• United States
  • Oregon
    • Eugene, Oregon, United States, 97403
      • Recruiting
      • Institute for Health in the Built Environment, University of Oregon
      • Contact: Gwynne Mhuireach, PhD; Phone Number: 541-346-4694; Email: gwynhwyf@uoregon.edu
      • Principal Investigator: Gwynne Mhuireach, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

-

Exclusion Criteria:

• Body mass index (BMI) greater than or equal to 35 or less than or equal to 18.
• Age under 18 or over 45.
• Female who is pregnant or lactating.
• Irregular bowel movements and/or stool consistency.
• Plans to travel, move residences, or other major life change during the study period (August-October 2023).
• Unable to speak, read, and write English.
• Use of any of the following drugs within the last 6 months:
• systemic antibiotics, antifungals, antivirals or antiparasitics (intravenous, intramuscular, or oral);
• oral, intravenous, intramuscular, nasal or inhaled corticosteroids;
• cytokines;
• methotrexate or immunosuppressive cytotoxic agents;
• large doses of commercial probiotics consumed (greater than or equal to 108 cfu or organisms per day) - includes tablets, capsules, lozenges, chewing gum or powders in which probiotic is a primary component. Ordinary dietary components such as fermented beverages/milks, yogurts, foods do not apply.
• Acute disease at the time of enrollment (defer sampling until subject recovers). Acute disease is defined as the presence of a moderate or severe illness with or without fever.
• History of cancer except for squamous or basal cell carcinomas of the skin that have been medically managed by local excision.
• Unstable dietary history as defined by major changes in diet during the previous month, where the subject has eliminated or significantly increased a major food group in the diet.
• Recent history of chronic alcohol consumption defined as more than five 1.5-ounce servings of 80 proof distilled spirits, five 12-ounce servings of beer or five 5-ounce servings of wine per day.
• Any confirmed or suspected condition/state of immunosuppression or immunodeficiency (primary or acquired) including HIV infection.
• Major surgery of the GI tract, with the exception of cholecystectomy and appendectomy, in the past five years. Any major bowel resection at any time.
• History of active uncontrolled gastrointestinal disorders or diseases including:
• inflammatory bowel disease (IBD) including ulcerative colitis (mild-moderate-severe), Crohn's disease (mild-moderate-severe), or indeterminate colitis;
• irritable bowel syndrome (IBS) (moderate-severe);
• persistent, infectious gastroenteritis, colitis or gastritis, persistent or chronic diarrhea of unknown etiology, Clostridium difficile infection (recurrent) or Helicobacter pylori infection (untreated);
• chronic constipation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Garden First; Participants assigned to this study arm undergo the Garden-fresh Produce intervention during the first period and the Supermarket Produce intervention during the second period.	Other: Garden-fresh Produce; Participants are asked to consume the USDA-recommended amounts of fruits and vegetables harvested from their gardens.; Other: Supermarket Produce; Participants are asked to consume the USDA-recommended amounts of fruits and vegetables purchased from a supermarket.
Experimental: Supermarket First; Participants assigned to this study arm undergo the Supermarket Produce intervention during the first period and the Garden-fresh Produce intervention during the second period.	Other: Garden-fresh Produce; Participants are asked to consume the USDA-recommended amounts of fruits and vegetables harvested from their gardens.; Other: Supermarket Produce; Participants are asked to consume the USDA-recommended amounts of fruits and vegetables purchased from a supermarket.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in fecal bacterial abundance, as characterized by qPCR with "universal" bacterial primers	ANOVA statistical test of bacterial gene copies (a proxy for absolute abundance) used to compare whether Garden-Fresh Produce and Supermarket Produce interventions differentially affect fecal bacterial abundance.	Baseline, 1 week, 3 weeks
Difference in fecal microbial diversity, as characterized by shotgun metagenomics.	ANOVA statistical test of Shannon index used to compare whether Garden-Fresh Produce and Supermarket Produce interventions differentially affect fecal microbial diversity.	Baseline, 1 week, 3 weeks
Difference in fecal microbial composition, as characterized by shotgun metagenomics.	PERMANOVA statistical test used to compare whether Garden-Fresh Produce and Supermarket Produce interventions differentially affect fecal microbial composition.	Baseline, 1 week, 3 weeks
Presence of differentially abundant microbial taxa, as characterized by shotgun metagenomics.	Negative binomial GLM statistical test used to identify microbial taxa associated with either Garden-Fresh Produce or Supermarket Produce intervention.	Baseline, 1 week, 3 weeks

Collaborators and Investigators

• Sponsor: University of Oregon
• Investigators: Principal Investigator: Gwynne Mhuireach, PhD, University of Oregon

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2023
• Primary Completion (Estimated): December 31, 2024
• Study Completion (Estimated): December 31, 2024

Study Registration Dates

• First Submitted: May 24, 2024
• First Submitted That Met QC Criteria: July 16, 2024
• First Posted (Actual): July 17, 2024

Study Record Updates

• Last Update Posted (Actual): July 17, 2024
• Last Update Submitted That Met QC Criteria: July 16, 2024
• Last Verified: July 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 2023-67017-39054

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No