High-Resolution Measurements of Diet-Microbiome Interactions

Conditions

• IBS (Irritable Bowel Syndrome)

Eligibility Criteria

Sex

ALL

Age

18 Years - 75 Years

Healthy Volunteers

Accepted

Interventions

• Inulin — DIETARY_SUPPLEMENT
  Participants consume a standardized breakfast shake containing 15 g of inulin at one of the two study visits, according to the randomized meal sequence. At the other visit, they consume the same base shake without added inulin as the low-fiber control. Visits occur approximately one week apart.
• Low-fiber control breakfast shake — OTHER
  Participants consume the standardized low-fiber base breakfast shake without added inulin at one of the two study visits, according to the randomized meal sequence. This condition serves as the within-participant control. Visits occur approximately one week apart.
• Atmo Gas-Sensing Capsule — DEVICE
  At each of the two study visits, participants will swallow one Atmo gas-sensing capsule with the assigned standardized breakfast shake at t=0. As it transits the gastrointestinal tract, the wireless capsule records regional luminal hydrogen (H2), carbon dioxide (CO2), oxygen-related signals, temperature, and transit-related data. Data are transmitted by radiofrequency to a wearable receiver for analysis. Capsule passage will be monitored after each visit.
• CapScan Regional Fluid-Sampling Capsule — DEVICE
  At each of the two study visits, participants will swallow one CapScan capsule at t=4 hours. CapScan is a single-use, passive ingestible device that collects regional gastrointestinal luminal fluid as it transits the intestine. The collected samples will be used for ex vivo microbiome and multiomic analyses. The device passes in the stool and is retrieved by the participant using the provided retrieval materials for subsequent processing.

Study Details

The goal of this clinical trial is to characterize regional intestinal fermentation physiology and determine how the response to fermentable dietary fiber differs between healthy individuals and individuals with irritable bowel syndrome (IBS). The study will use ingestible capsule technologies to directly measure intestinal gases and regional microbiome composition following low-fiber and high-fiber meal challenges. The main questions it aims to answer are: Does the change in regional intestinal gas levels following a fermentable-fiber challenge differ between participants with IBS and healthy controls? How are regional intestinal gas dynamics associated with microbiome composition, breath gases, serum short-chain fatty acids, glucose dynamics, metabolites, and gastrointestinal symptoms? Researchers will compare participants with IBS to healthy controls to determine whether intestinal fermentation responses to dietary fiber differ between these populations. Participants will: Complete two study visits approximately one week apart. At one visit, participants will receive a low-fiber control meal, and at the other visit, they will receive the same base meal containing 15 g of inulin. The order of the two meals will be assigned at random. Swallow an Atmo gas-sensing capsule to measure intestinal H2, CO2, and O2 and a CapScan capsule to collect regional intestinal fluid for microbiome analysis. Undergo serial blood and breath sampling and gastrointestinal symptom assessments during each 8-hour study visit. Complete stool and urine collections, dietary assessment, and continuous glucose monitoring before and/or after the study visits.

Key Dates

First listed

Oct 5, 2026

Start date

Oct 31, 2026

Status verified

Sep 2026

Primary completion

Oct 31, 2028

Completion

Dec 31, 2028

Study Design

Enrollment

40 participants (estimated)

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Arms

• Experimental: Healthy controls
  The Healthy cohort consists of individuals without a diagnosed chronic gastrointestinal disorder or ongoing gastrointestinal symptoms warranting clinical evaluation. Participants complete two study visits approximately one week apart and receive both meal conditions in randomized order: low-fiber control followed by 15 g of inulin, or 15 g of inulin followed by low-fiber control. At each visit, participants consume the assigned standardized breakfast shake with the Atmo gas-sensing capsule at t=0 and ingest the CapScan regional sampling capsule at t=4 hours.
• Experimental: Irritable Bowel Syndrome (IBS)
  The IBS cohort consists of individuals who meet Rome IV diagnostic criteria for irritable bowel syndrome. Participants complete two study visits approximately one week apart and receive both meal conditions in randomized order: low-fiber control followed by 15 g of inulin, or 15 g of inulin followed by low-fiber control. At each visit, participants consume the assigned standardized breakfast shake with the Atmo gas-sensing capsule at t=0 and ingest the CapScan regional sampling capsule at t=4 hours.

Primary Outcome Measure

Successful Acquisition of a Complete Regional Multiomic Fermentation-Physiology Dataset [ Time Frame: up to 12 months ]

Central Contacts

• Roujheen Sabetan, MPH
  925-963-7021
  [email protected]
• Jacob T Hizon, BS
  619-874-4562
  [email protected]

Locations (1)

Find similar trials in Stanford, CA

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