Using the Smart Underwear Device to Determine a Baseline of Flatus Activity Normalized to Fiber Intake

NCT07134543 | Recruiting

• 1 other identifier: Human Flatus Atlas
• Study Type: observational
• Target: 500
• Locations: 1 country
• Sites: 2

Brief Summary

The goal of this observational study is to quantify the typical frequency of flatulence in healthy adults, normalized by fiber intake, using the Smart Underwear device. The study will enroll a maximum of 500 adults across the United States who will wear the device for three consecutive days while continuing their usual daily activities. The main questions it aims to answer are:

• What is the average frequency of flatus events in a general adult population?
• How does dietary fiber intake influence flatus frequency and microbiome activity? Researchers will collect gas sensor data from the Smart Underwear device alongside dietary information logged in a mobile app to assess the relationship between diet and microbiome activity. Participants will:
• Complete an online eligibility survey, consent form, and background questionnaire.
• Wear the Smart Underwear device for at least 12 hours per day for three consecutive days.
• Log all meals with photos using a custom smartphone app.
• Complete a short post-wear survey about device comfort and usability. All study procedures will be conducted remotely. Data will be analyzed in de-identified form to evaluate baseline flatulence patterns, normalized to fiber intake, in the general adult population.

Conditions

All Health Backgrounds to Determine a Baseline of Flatus Activity

Outcome Measures

Primary Outcomes (1)

• Microbiome Activity Index

  The Microbiome Activity Index is a composite measure reflecting gut microbiome activity, calculated from both flatus frequency and hydrogen gas concentration. The index uses the absolute value of the first derivative of the hydrogen sensor signal to better capture flatus intensity, reduce baseline noise, and mitigate sensor saturation at high hydrogen levels. This composite approach ensures a more accurate representation of gut microbiome activity than relying on flatus count or hydrogen concentration alone. Data are collected using a wearable device ("Smart Underwear") and uploaded to the Human Flatus Atlas app.

  12 hours each day for 3 days

Secondary Outcomes (4)

• Total flatus count

  12 hours each day for 3 days

• Flatus Per Hour

  12 hours each day for 3 days

• Microbiome Activity Index Comparative Score

  12 hours each day for 3 days

• Fiber-Normalized Flatus Frequency

  12 hours each day for 3 days

Study Arms (1)

American adults

American adults that are at least 18 years old, live in the United States, are not pregnant or lactating, and agree to wear the Smart Underwear device.

Eligibility Criteria

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

Study Population

Residents of the US

You may qualify if:

• years old or older
• Lives in the US
• Is not pregnant or lactating
• Is willing to wear the Smart Underwear device as instructed in the study procedures

You may not qualify if:

• Younger than 18 years old
• Lives outside the US
• Is pregnant or lactating
• Is not willing to wear the Smart Underwear device as instructed in the study procedures

Sponsors & Collaborators

• University of Maryland, College Park: lead

Study Sites (2)

Bioscience Research Building

College Park, Maryland, 20742, United States

NOT YET RECRUITING

University of Maryland Bioscience Research Building

College Park, Maryland, 20742, United States

RECRUITING

Central Study Contacts

Brantley Hall, PhD

CONTACT

5407978040; brantley@umd.edu

Study Design

• Study Type: observational
• Observational Model: ECOLOGIC OR COMMUNITY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 14, 2025
• First Posted: August 21, 2025
• Study Start: December 1, 2025
• Primary Completion (Estimated): September 5, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: December 23, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL

Locations

US (2)