Dietary Impact on Intestinal Sulfate Metabolism

This is a 5-week crossover pilot study of 15 highly motivated healthy volunteers who will consume two 7-day intervention diets: 1) a diet low in sulfur-containing amino acids (Low-S diet), emphasizing plant-based foods and fat sources; and 2) a diet high in sulfur-containing amino acids (High-S diet), emphasizing animal protein and fat sources. A 14-day washout period will follow each intervention, in which participants will eat their typical diets.

Study Overview

• Status: Completed
• Conditions: Healthy Nutrition
• Intervention / Treatment: Behavioral: Plant-Based Diet then animal-based diet; Behavioral: Animal-based diet then plant-based diet

• Study Type: Interventional
• Enrollment (Actual): 15
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Minneapolis, Minnesota, United States, 55455
      • University of Minnesota

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Provide informed consent
• Ambulatory and community dwelling
• Able and willing to comply with the study schedule and procedures
• 18 - 80 years of age
• BMI between 18.5 - 40.0 kg/m2
• Omnivorous or willing to consume animal products through duration of study

Exclusion Criteria:

• Antibiotic use within 3 months
• Planned antibiotic therapy within the period of the study, e.g., perioperative antibiotics.
• Use of sulfonamides or sulfasalazine, as these sulfur-containing medications may confound results
• Use of 5-aminosalicylates (5-ASA), as they are known to inhibit sulfidogenesis
• History of anaphylactic food allergies, e.g., peanuts, seafood.
• Food intolerances and allergies, including gluten sensitivity, lactose intolerance, and intolerance of high fiber dietary content.
• Strict vegan eating practices, with refusal to consume animal products.
• Planned use of oral probiotics while on study.
• Serious, concomitant illness that, in the opinion of the Investigator, would interfere with evaluation of safety or efficacy, or put the participant at risk of harm from study participation.
• Significant alcohol use, defined as > 20 g/day in females and > 30 g/day in males for a period of 3 months within one year prior to screening.
• Underlying chronic gastrointestinal disease that can cause diarrhea, including short bowel syndrome, irritable bowel syndrome, malabsorption, and celiac disease.
• History of partial or complete colectomy.
• History of malabsorptive bariatric surgery.
• Currently participating in another clinical study.
• Legally incompetent and unable to understand the study's purpose, significance and consequences, and to make decisions accordingly.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Plant-based then animal based; plant based: diet low in sulfur-containing amino acids (Low-S diet), emphasizing plant-based foods and fat sources animal based: A diet high in sulfur-containing amino acids (High-S diet), emphasizing animal protein and fat sources	Behavioral: Plant-Based Diet then animal-based diet; Participants started with plant based diet: high in fiber, low in animal products for 7 days, with 14 day washout period between interventions. Following that, participants were switched to animal-based diet: high in animal products, low in fiber for 7 days.
Active Comparator: Animal-based then plant based; plant based: diet low in sulfur-containing amino acids (Low-S diet), emphasizing plant-based foods and fat sources animal based: A diet high in sulfur-containing amino acids (High-S diet), emphasizing animal protein and fat sources	Behavioral: Animal-based diet then plant-based diet; Participants were started with animal-based diet: high in animal products, low in fiber for 7 days, with 14 days washout period between interventions. Following that, participants were switched to plant-based diet: high in fiber, low in animal products for 7 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effect of Short-term (1-week) Plant- and Animal-based Eating Patterns on Hydrogen Sulfide Production	Determine the effect of short-term (1-week) plant- and animal-based eating patterns on ex vivo fecal hydrogen sulfide production in healthy human volunteers We will measure fecal hydrogen sulfide production ex vivo in ppm/g of dry weight of stool	Following 1-week of plant- and animal-based eating patterns

Collaborators and Investigators

• Sponsor: University of Minnesota
• Investigators: Principal Investigator: Alexander Khoruts, University of Minnesota

Study record dates

Study Major Dates

• Study Start (Actual): December 7, 2016
• Primary Completion (Actual): December 31, 2020
• Study Completion (Actual): March 18, 2021

Study Registration Dates

• First Submitted: March 4, 2022
• First Submitted That Met QC Criteria: April 13, 2022
• First Posted (Actual): April 19, 2022

Study Record Updates

• Last Update Posted (Estimated): December 5, 2023
• Last Update Submitted That Met QC Criteria: December 1, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Keywords: Microbiome; Ulcerative colitis; Hydrogen sulfide; Plant-based; Animal-based
• Other Study ID Numbers: GI-2016-25182

Drug and device information, study documents

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