Health TrialsbyHealthPanel

High-Resolution Measurements of Diet-Microbiome Interactions

ConditionIBS (Irritable Bowel Syndrome)
Trial statusNot yet recruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-75
SponsorStanford University

About this trial

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.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Age 18-75 years.

Able to provide written informed consent.

Able and willing to swallow capsules and complete all study procedures.

For the Healthy cohort: no history of a diagnosed chronic GI disorder and no ongoing GI symptoms warranting clinical evaluation.

Disqualifiers

Known or suspected gastrointestinal stricture or physiological/mechanical gastrointestinal obstruction.

Gastrointestinal fistula.

Dysphagia or other swallowing disorder affecting the ability to swallow food, pills, or capsules.

Gastrointestinal surgery within the past 3 months.

Trial design

Design model

Crossover

Treatments tested in this trial

  • 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 intervention

    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.

Treatment groups

40 Participants
are divided into 2 treatment groups
Group A: Healthy controlsExperimental treatment 4 interventions
Group B: Irritable Bowel Syndrome (IBS)Experimental treatment 4 interventions

Trial outcomes

Primary outcomes

1

Successful Acquisition of a Complete Regional Multiomic Fermentation-Physiology Dataset

To successfully obtain a complete regional multiomic fermentation-physiology dataset - defined as paired Atmo gas capsule data (H2, CO2, O2), CapScan regional microbiome/fluid sampling, stool microbiome sequencing, and breath testing (H2, CH4, H2S) with serum SCFA measurements - from at least 30 of the 40 enrolled participants (15 healthy, 15 IBS), across both study visits. Primary outcome measure: the number and proportion of enrolled participants from whom a complete multiomic dataset is successfully obtained across both study visits.

Time frame
up to 12 months

Secondary outcomes

1

Change in Regional Intestinal Gas Concentrations Following Inulin Challenge

Regional hydrogen (H2), carbon dioxide (CO2), and oxygen (O2) concentration-time profiles will be measured using the Atmo gas-sensing capsule. Changes in gas concentrations between the low-fiber control visit and the 15 g inulin visit will be compared within participants and between healthy and IBS groups, including regional differences between the small intestine and colon.

Time frame
Through completion of both study visits, 2 week
2

Regional Intestinal Microbiome Composition Following Dietary Fiber Challenge

Microbial composition will be characterized from regional intestinal fluid samples collected using the CapScan capsule and from stool samples. Microbiome profiles will be evaluated across intestinal regions and compared between the low-fiber and inulin visits and between healthy and IBS participants.

Time frame
Through completion of sample collection, up to 72 hours after each study visit
3

Change in Breath H2, CH4, and H2S Concentrations Following Inulin Challenge

Breath hydrogen (H2), methane (CH4), and hydrogen sulfide (H2S) concentrations will be measured every 30 minutes during each 8-hour study visit. Concentration-time profiles will be compared between the low-fiber and inulin visits and between healthy and IBS participants.

Time frame
8 hours during each study visit
4

Change in Serum Short-Chain Fatty Acid Concentrations Following Inulin Challenge

Serum short-chain fatty acid (SCFA) concentrations will be measured from serial blood samples collected every 30 minutes during each 8-hour study visit. SCFA concentration-time profiles will be compared between the low-fiber and inulin visits and between healthy and IBS participants.

Time frame
8 hours during each study visit

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Stanford University

Lead sponsor

Source ClinicalTrials.gov

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