Smart Underwear to Measure Diet-Induced Hydrogen Sulfide Production

NCT06802276 | Recruiting

• 2 other identifiers: 24-1861R33DK132310-03
• Study Type: interventional
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to evaluate the ability of a wearable Smart Underwear prototype device to quantify diet-induced changes in gut microbial hydrogen sulfide (H₂S) production. The core design is a single-site, 2-period, crossover feeding study with 6-day diet periods and an approximately 11-day washout period. Participants are fed each of two isocaloric diets designed to contrast gut microbial H₂S production (i.e., a high cysteine vs. low cysteine diet), in a random order.

Conditions

Hydrogen Sulfide; Gastrointestinal Microbiome

Keywords

Hydrogen Sulfide; H2S; Diet; Cysteine; Gut Microbiome

Outcome Measures

Primary Outcomes (1)

• Hydrogen sulfide (H2S)

  Participants will be instructed to wear the Smart Underwear device for all waking hours during the baseline and feeding periods except for bathing and exercise. The Smart Underwear device does not need to be worn while sleeping due to the decreased frequency of flatus. Participants will be warned by the Smart Underwear device if the device is not worn for at least 12 hours per day or if the device detects that it is being worn incorrectly. Aggregate metrics from the device will be included in either the on-site or virtual discussions with staff.

  Daily for 6 days during each dietary intervention period (total of 12 days).

Secondary Outcomes (5)

• Microbiome Activity Index

  Daily for 6 days during each dietary intervention period (total of 12 days).

• Gastrointestinal Microbiome

  The final day of each 6-day dietary intervention period (total of 2 days).

• Experienced Symptoms Questionnaire

  The final day of each 6-day dietary intervention period (total of 2 days).

• Participant Wearing Time

  Daily for 6 days during each dietary intervention period (total of 12 days).

• Systolic Blood Pressure (SBP)

  The final day of each 6-day dietary intervention period (total of 2 days).

Study Arms (2)

High Cysteine Diet

ACTIVE COMPARATOR

A dietary pattern designed to have a high level of dietary cysteine

Other: High Cysteine Diet

Low Cysteine Diet

OTHER

A dietary pattern designed to have a low level of dietary cysteine

Other: Low Cysteine Diet

Interventions

High Cysteine Diet OTHER

A healthy diet pattern which contains high levels of cysteine or cysteine-related compounds. The high and low cysteine diets will be designed by a research dietician to differ primarily in their concentration of cysteine while providing similar levels of calories, protein, fats, carbohydrates, fiber, and several micronutrients. No additional supplementation of cysteine will be used. Examples of high cysteine foods: chicken, eggs, lentils, yogurt, garlic, cheese, soybeans

High Cysteine Diet

Low Cysteine Diet OTHER

A healthy diet pattern which contains low levels of cysteine or cysteine-related compounds. The high and low cysteine diets will be designed by a research dietician to differ primarily in their concentration of cysteine while providing similar levels of calories, protein, fats, carbohydrates, fiber, and several micronutrients. The low cysteine diet includes lower-protein food sources. Examples of low cysteine foods: rice, bread, oranges, bananas, lettuce, snow peas, peppers

Low Cysteine Diet

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may not qualify if:

• Generally healthy volunteers defined as having no major known health conditions (e.g., diabetes, cancer, hypertension, etc.).
• Normal bowel movements, with approximately 1 bowel movement reported per day
• Willing to discuss flatus
• Ages \>18yrs
• Willing to complete the entire study protocol, i.e. eating all of the food that is provided and completing all required measurements.
• Self-report or other evidence of diabetes, other endocrine/metabolic abnormality, dyslipidemia, morbid obesity, severe hypertension, chronic kidney disease, liver disease, pulmonary disease, gastrointestinal, and cardiovascular diseases
• Chronic medications for any of the above conditions
• Food allergy that interferes with ability to complete the study
• Food preferences, intolerance, or dietary requirements that would interfere with diet adherence
• Planned dietary changes during the study period
• Lack of appropriate food refrigeration and preparation equipment (e.g.- oven or microwave)
• Pregnancy or planned pregnancy in the next month
• Physical measurements: BMI \> 35 kg/m2

Sponsors & Collaborators

• University of Colorado, Denver: lead
• University of Maryland, College Park: collaborator
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): collaborator

Study Sites (1)

University of Colorado Anschutz Medical Campus

Aurora, Colorado, 80045, United States

RECRUITING

Study Officials

• Noel T Mueller, PhD

  University of Colorado, Denver

  PRINCIPAL INVESTIGATOR

• Andrew B Hall, PhD

  University of Maryland, College Park

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Noel T Mueller, PhD

CONTACT

414-779-1167; noel.mueller@cuanschutz.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The investigators and the outcomes assessors will not know which order of diets the participant has been assigned. The participant will not be explicitly told which diet he or she is receiving during each period, but by the nature of the differences between the high cystine and low cystine diets, the participant may be able to guess based on the menus.
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: The study design is a two-period crossover feeding study, in which participants will be randomly assigned to each of a high cysteine and low cysteine isocaloric diet for a 6-day period each. Additionally, a 3-day baseline period will occur prior to each dietary intervention period. Diet intervention periods will be separated by a washout period. This washout period may vary slightly between participants and will last for a minimum of 9 days and a maximum of 13 days.

Study Record Dates

• First Submitted: January 15, 2025
• First Posted: January 31, 2025
• Study Start: May 21, 2025
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 30, 2027
• Last Updated: April 29, 2026

Record last verified: 2026-04

Locations

US (1)