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High-Resolution Measurements of Diet-Microbiome Interactions

28 settembre 2026 aggiornato da: Sean Spencer, Stanford University

First-Principles Mapping of Regional Fermentation Physiology in the Human Intestine With Ingestible Capsules

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.

Panoramica dello studio

Descrizione dettagliata

Irritable Bowel Syndrome (IBS) affects an estimated 25-45 million people in the United States, accounts for roughly 20-40% of gastroenterology visits, and imposes a major societal burden, with annual U.S. costs estimated at approximately $1.7-$10 billion in direct medical spending and approximately $20 billion in indirect costs from lost productivity (Hulisz 2004; Leong et al. 2003; Canavan et al. 2014). Despite this burden, IBS remains poorly understood, and no validated biochemical diagnostic or curative therapy currently exists (Lacy et al. 2021; Kim et al. 2017).

In most individuals, a high-fiber diet supports a healthy microbiome and improves health outcomes without adverse symptoms (Fu et al. 2022). In patients with IBS, however, fermentable fiber is known to worsen symptoms such as bloating, flatulence, and abdominal pain; patients are often advised to restrict fermentable fiber intake (e.g., a low-FODMAP diet), and antibiotics are sometimes used therapeutically to suppress fermentation (Halmos et al. 2014; Lacy et al. 2021). These clinical observations motivate the mechanistic hypothesis underlying this protocol: that IBS symptoms may arise, at least in part, from disordered microbial fermentation and impaired intestinal gas handling.

Progress toward this goal has been limited by the absence of direct clinical tools capable of quantifying fermentation physiology in vivo and by intestinal region. Current clinical testing (e.g., hydrogen/methane breath testing) provides only an indirect, systemic proxy for fermentation and remains variably standardized (Rezaie et al. 2017; Pitcher et al. 2022).

The human intestine is more than 30 feet in length and is home to regionally distinct microbial communities that closely track local gut physiology (Martinez-Guryn et al. 2019). Recently developed non-invasive capsule-based microbiome sampling has shown that the small intestine and proximal colon harbor communities that are distinct from stool and disproportionately altered in IBS (Shalon et al. 2023; Leite et al. 2020; Chung et al. 2016).

This protocol leverages two complementary ingestible capsule technologies - a real-time gas-sensing capsule (Atmo) and a regional fluid/microbiome-sampling capsule (CapScan) - together with stool, urine, breath, and blood-based measurements, to establish regional gas production and consumption profiles in healthy individuals and patients with IBS.

The Healthy and IBS cohorts are defined by baseline clinical status and are not randomized. Within each cohort, participants undergo a randomized two-period crossover of meal order. Each participant receives both the low-fiber control meal and the 15 g inulin meal, with the order assigned at random.

Tipo di studio

Interventistico

Iscrizione (Stimato)

40

Fase

  • Non applicabile

Contatti e Sedi

Questa sezione fornisce i recapiti di coloro che conducono lo studio e informazioni su dove viene condotto lo studio.

Contatto studio

Backup dei contatti dello studio

Luoghi di studio

    • California
      • Stanford, California, Stati Uniti, 94305
        • Stanford University
        • Contatto:

Criteri di partecipazione

I ricercatori cercano persone che corrispondano a una certa descrizione, chiamata criteri di ammissibilità. Alcuni esempi di questi criteri sono le condizioni generali di salute di una persona o trattamenti precedenti.

Criteri di ammissibilità

Età idonea allo studio

Da 18 anni a 75 anni (Adulto, Adulto più anziano)

Accetta volontari sani

Sì

Sessi ammissibili allo studio

Tutto

Descrizione

Inclusion Criteria:

  1. Age 18-75 years.
  2. Able to provide written informed consent.
  3. Able and willing to swallow capsules and complete all study procedures.
  4. For the Healthy cohort: no history of a diagnosed chronic GI disorder and no ongoing GI symptoms warranting clinical evaluation.
  5. For the IBS cohort: meets Rome IV diagnostic criteria for IBS, with a prior clinical hydrogen/methane breath test on record sufficient to assign a breath-test subtype.
  6. Willing and able to complete a virtual (Zoom) screening visit and two in-clinic study visits approximately one week apart.

Exclusion Criteria:

  1. Known or suspected gastrointestinal stricture or physiological/mechanical gastrointestinal obstruction.
  2. Gastrointestinal fistula.
  3. Dysphagia or other swallowing disorder affecting the ability to swallow food, pills, or capsules.
  4. Gastrointestinal surgery within the past 3 months.
  5. Prior gastrointestinal surgery that alters luminal anatomy (e.g., bowel resection or bariatric surgery).
  6. Diverticulitis.
  7. Gastric bezoar.
  8. Radiation enteritis.
  9. Pacemaker or other implanted or portable electromechanical medical device.
  10. Pregnancy or breastfeeding.
  11. BMI ≥40 kg/m².
  12. Use of antibiotics, probiotics, or prebiotics within 4 weeks prior to enrollment.
  13. Use of proton-pump inhibitors (e.g., omeprazole, lansoprazole, esomeprazole [Nexium®]) within 7 days prior to the study procedure.
  14. Use of histamine blockers, motility-altering medications, narcotic analgesics, or anticholinergic medications within 3 days prior to the study procedure.
  15. Use of antiemetics/5-HT3 antagonists, macrolide antibiotics, or 5-HT4-modulating medications within 2 days prior to the study procedure.
  16. Use of antacids (e.g., Gaviscon®, Mylanta®, TUMS) within 1 day prior to the study procedure.
  17. Diabetes or use of medications affecting glucose handling.
  18. Known allergy or intolerance to inulin or other study meal components.
  19. Current participation in another interventional study.

Piano di studio

Questa sezione fornisce i dettagli del piano di studio, compreso il modo in cui lo studio è progettato e ciò che lo studio sta misurando.

Come è strutturato lo studio?

Dettagli di progettazione

  • Scopo principale: Scienza basilare
  • Assegnazione: Randomizzato
  • Modello interventistico: Assegnazione incrociata
  • Mascheramento: Doppio

Armi e interventi

Gruppo di partecipanti / Arm
Intervento / Trattamento
Sperimentale: 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.

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.

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.

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.

Altri nomi:
  • Atmo Gas Capsule System

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.

Altri nomi:
  • CapScan
  • Envivo Bio Collection Device
Sperimentale: 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.

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.

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.

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.

Altri nomi:
  • Atmo Gas Capsule System

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.

Altri nomi:
  • CapScan
  • Envivo Bio Collection Device

Cosa sta misurando lo studio?

Misure di risultato primarie

Misura del risultato
Misura Descrizione
Lasso di tempo
Successful Acquisition of a Complete Regional Multiomic Fermentation-Physiology Dataset
Lasso di tempo: up to 12 months

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.

up to 12 months

Misure di risultato secondarie

Misura del risultato
Misura Descrizione
Lasso di tempo
Change in Regional Intestinal Gas Concentrations Following Inulin Challenge
Lasso di tempo: Through completion of both study visits, 2 week

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.

Through completion of both study visits, 2 week
Regional Intestinal Microbiome Composition Following Dietary Fiber Challenge
Lasso di tempo: Through completion of sample collection, up to 72 hours after each study visit

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.

Through completion of sample collection, up to 72 hours after each study visit
Change in Breath H2, CH4, and H2S Concentrations Following Inulin Challenge
Lasso di tempo: 8 hours during each study visit

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.

8 hours during each study visit
Change in Serum Short-Chain Fatty Acid Concentrations Following Inulin Challenge
Lasso di tempo: 8 hours during each study visit

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.

8 hours during each study visit
Change in Gastrointestinal Symptom Severity Following Inulin Challenge
Lasso di tempo: 8 hours during study visit

Participant-reported gastrointestinal symptoms, including bloating/distention, abdominal pain/cramping, flatulence, nausea, and urgency, will be assessed throughout each study visit. Symptom trajectories will be compared between the low-fiber and inulin visits and between healthy and IBS participants.

8 hours during study visit
Glucose Response Following Dietary Fiber Challenge
Lasso di tempo: Through CGM monitoring throughout 2 weeks including both study visits.

Continuous glucose monitor (CGM)-derived glucose profiles will be evaluated following the low-fiber and inulin meal challenges. Glucose responses will be compared within participants across study visits and between healthy and IBS groups.

Through CGM monitoring throughout 2 weeks including both study visits.
Atmo Capsule Gastrointestinal Transit Time
Lasso di tempo: From capsule ingestion through passage, confirmation up to 72 hours after clinic visit.

Quantify the gastrointestinal transit time of the Atmo capsule after participant ingestion.

From capsule ingestion through passage, confirmation up to 72 hours after clinic visit.

Collaboratori e investigatori

Qui è dove troverai le persone e le organizzazioni coinvolte in questo studio.

Investigatori

  • Direttore dello studio: Michael Fischbach, PhD, Stanford University
  • Investigatore principale: Sean P Spencer, MD PhD, Stanford University
  • Direttore dello studio: Benjamin Good, PhD, Stanford University
  • Direttore dello studio: Jonas Cremer, PhD, Stanford University

Studiare le date dei record

Queste date tengono traccia dell'avanzamento della registrazione dello studio e dell'invio dei risultati di sintesi a ClinicalTrials.gov. I record degli studi e i risultati riportati vengono esaminati dalla National Library of Medicine (NLM) per assicurarsi che soddisfino specifici standard di controllo della qualità prima di essere pubblicati sul sito Web pubblico.

Studia le date principali

Inizio studio (Stimato)

1 ottobre 2026

Completamento primario (Stimato)

1 ottobre 2028

Completamento dello studio (Stimato)

1 dicembre 2028

Date di iscrizione allo studio

Primo inviato

28 settembre 2026

Primo inviato che soddisfa i criteri di controllo qualità

28 settembre 2026

Primo Inserito (Effettivo)

5 ottobre 2026

Aggiornamenti dei record di studio

Ultimo aggiornamento pubblicato (Effettivo)

5 ottobre 2026

Ultimo aggiornamento inviato che soddisfa i criteri QC

28 settembre 2026

Ultimo verificato

1 settembre 2026

Maggiori informazioni

Termini relativi a questo studio

Piano per i dati dei singoli partecipanti (IPD)

Hai intenzione di condividere i dati dei singoli partecipanti (IPD)?

NO

Informazioni su farmaci e dispositivi, documenti di studio

Studia un prodotto farmaceutico regolamentato dalla FDA degli Stati Uniti

No

Studia un dispositivo regolamentato dalla FDA degli Stati Uniti

Sì

prodotto fabbricato ed esportato dagli Stati Uniti

No

Queste informazioni sono state recuperate direttamente dal sito web clinicaltrials.gov senza alcuna modifica. In caso di richieste di modifica, rimozione o aggiornamento dei dettagli dello studio, contattare register@clinicaltrials.gov. Non appena verrà implementata una modifica su clinicaltrials.gov, questa verrà aggiornata automaticamente anche sul nostro sito web .

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