CompletedEarly Phase 1

Biomarkers of Diet-microbiota Interactions in Irritable Bowel Syndrome

Canada30 participantsStarted 2021-07-15

Plain-language summary

Most patients suffering from the irritable bowel syndrome (IBS) report that ingestion of certain foods is a major trigger of symptoms, but the reason is unclear. Previous studies have shown that foods containing poorly absorbed carbohydrates (FODMAPs) are fermented by the bacteria in our bowels and these cause symptoms in some but not all patients. Gut bacteria are capable of producing various products, such as neuroimmune mediator histamine, that may be related to IBS symptoms. Our recent data suggest that consumption of FODMAPs promotes production of bacterial histamine. The main objective of this study is to investigate bacterial production of histamine and its relationship to IBS symptoms. The study will involve 6 weeks on a low-FODMAP diet with three three-day interventions consisting of High- or Low-FODMAP drinks along with probiotics or placebo capsules. The patient's bacteria and metabolites will be analyzed at various time points.

Who can participate

Age range

18 Years – 75 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Adults aged 18-75 with IBS (Rome IV criteria) who have self-reported previous improvement in their IBS symptoms while on a low FODMAP diet, or when excluding certain high-FODMAP foods, or patients in whom histamine is expected to play a key role (either diagnosed with high histamine producing bacteria, or improved IBS symptoms after using antihistamines). Individuals should be able to swallow size 00 capsules. Exclusion Criteria: * Concurrent significant organic GI pathology (i.e. celiac, IBD, etc.) * Concurrent systemic disease (such as diabetes) and/or laboratory abnormalities considered by investigators to be risky or that could interfere with data collection * History of active cancer in the last 5 years, other than basal cell cancer * Pregnant or breastfeeding women * Active or recent participation (\< 1 month) in a clinical study, except for SPOR IMAGINE * Use of antibiotics, probiotics, or ACE inhibitors during, or one month prior to the study * Use of new medications less than 4 weeks prior to the study. * Allergies to any of the ingredients used in the study * Any immune-compromising conditions

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Metabolites in stool, urine and blood

Timeframe: six weeks

Trial details

NCT IDNCT04364750

SponsorMcMaster University

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-02-10

View on ClinicalTrials.gov More Irritable Bowel Syndrome trials