Irritable Bowel Syndrome (IBS)NCT07688044
The Role That Food and Bacteria Play in Generating Abdominal Pain
A study testing FODMAP Challenge in people with Irritable Bowel Syndrome (IBS), run by David Reed at 1 site in Canada.
Trial summary
Irritable Bowel Syndrom (IBS) affects up to five percent of Canadians and has proven difficult to treat. Our research will explore how a type of dietary carbohydrate, called FODMAPS, contributes to chronic abdominal pain in irritable bowel syndrome (IBS). Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Irritable Bowel Syndrome (IBS)
- What is being tested?
- FODMAP Challenge
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteCanada
- Study dates
- 16 Mar 2026to Mar 2031
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18-70 with IBS (Rome IV (now V) criteria)
- PROMIS belly pain score >12
Who cannot join
- Concurrent significant organic GI pathology (i.e. celiac, IBD, etc.) as some symptoms may be related to their disease and not IBS.
- Concurrent systemic disease and/or laboratory abnormalities considered by investigators to be risky or that could interfere with data collection.
- Major gastrointestinal surgery (e.g. Roux en y, bowel resection) as symptoms may be related to previous surgery rather than IBS.
- Body mass index above 35 kg/m2 as it is unknown how mediators in the GI tract that may be involved in pain signaling in the gut are affected by obesity.
- History of active cancer in the last 5 years, other than basal cell cancer as the treatment may have impacted the GI tract.
- Pregnant or breastfeeding women.
Show all 12Show fewer
- Active or recent participation (< 1 month) in a clinical study.
- Use of antibiotics, probiotics, during, or one month prior to the study as may affect gut microbiota.
- Use of new medications less than 4 weeks prior to the study as may alter gut microbiota and/or IBS symptoms.
- Allergies to any of the ingredients used in the study.
- Any immune-compromising conditions as may affect GI symptoms.
- Currently being treated for eating disorder, schizophrenia, psychosis or other acute mental disorders as participating in a diet challenge study may have negative impact on these disorders.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
Hotel Dieu Hospital
Kingston, Ontario, K7L 5G2
Celine Morissette, (613) 449-5433, celine.morissette@kingstonhsc.ca
About this study
Official title: The Role of Gut Microbiota in Patient Responses to a Dietary Therapy for Abdominal Pain
Irritable Bowel Syndrom (IBS) affects up to five percent of Canadians and has proven difficult to treat. Our research will explore how a type of dietary carbohydrate, called FODMAPS, contributes to chronic abdominal pain in irritable bowel syndrome (IBS). FODMAPs, are poorly digested carbohydrates and removing FODMAPs from the diet relieves abdominal pain in approximately half of IBS patients. Unfortunately, FODMAPs are contained in many foods, which makes it challenging for patients to remain on a low FODMAP diet for extended periods. Our proposed research will identify which subtypes of FODMAPs are most responsible for increasing pain and will tease apart whether the pain-causing effects of FODMAPs rely on the gut microbiota or not. To identify which specific type of FODMAP causes pain, IBS patients will adopt a low FODMAP diet and then individual FODMAP subtypes will be added back to their diet while monitoring changes to their pain. Stool samples will be collected from the participants to determine whether the composition of the gut microbiota or the chemicals that it produces are changed when symptoms are improved or exacerbated by manipulating FODMAP availability. In parallel studies, the microbiota of each IBS patient will be grown in specialized conditions to mimic the environment of the gut. These patient microbial communities will be exposed to the same FODMAP manipulations as the patients themselves experience. This will allow us to test whether the changes in gut microbiota composition and the chemicals produced that occur in IBS patients in response to FODMAP manipulations also occur when only the microbiota is exposed to these manipulations. Together, these studies will aim to optimize a dietary therapy for a common chronic pain condition and will provide novel insights into how diet affects the chemicals the gut microbiota produces that contribute to abdominal pain.
- Conditions
- Irritable Bowel Syndrome (IBS)
- Being tested
- FODMAP Challenge
- Keywords
- FODMAPs, Microbiota, Neuroactive mediators, Abdominal pain, GI pain signaling
- Medical subject headings
- Irritable Bowel Syndrome, Abdominal Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FODMAP ChallengeOther
Prior to beginning the LFD, each participant will provide a stool sample. This will be used to inoculate a continuous culture system (chemostat) as these vessels maintain fecal microbial communities under controlled anaerobic conditions. After reaching steady state in culture media with FODMAPs (7 days), the media will be switched to a low FODMAP media for 7 days. Then each vessel will be exposed to the same FODMAP subgroups challenges and glucose challenge as the participants for 3 days. At each stage (i.e., steady state, after low fodmap media, after each challenge) culture supernatant will be collected. This supernatant will be used to test its neurophysiological effects on pain sensing neurons in pre-clinical studies. In addition, participants will provide a stool sample at each stage. Fecal supernatants will be produced from these samples and the neurophysiological effects of the fecal supernatants will be tested in pre-clinical studies.
| Study group | Role | What they receive |
|---|---|---|
| FODMAP Challenge | Experimental | Participants will be on a low fodmap diet (LFD) for a total of 6 weeks. After two weeks on LFD, each participant whose IBS-symptom severity score was reduced by 50 points will be deemed a responder, and will proceed to the next stage of the study. This will entail each participant remaining on the LFD while beginning 4 four-day individual challenges every 7 days consisting of 3 FODMAP subgroup challenges (galacto-oligosaccahride, fructan, and sorbitol) and 1 glucose challenge as a non-FODMAP carbohydrate control. Each challenge will comprise of a 4-day challenge with one of the three FODMAP subgroups or a glucose challenge (as a negative control) followed by a 3-day washout period with any residual symptoms resolved while remaining on the LFD prior to the next challenge. Receives: Other: FODMAP Challenge |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Dorsal Root Ganglion (DRG) neuron rheobase by chemostat supernatant
DRG neurons will be incubated overnight with chemostat supernatant after steady state, low fodmap media, fodmap subtype media and glucose media. Patch clamp recordings will be made from neurons the following day the rheobase (minimum current required to elicit an action potential in a neuron) will be measured. The mean rheobase for neurons exposed to the different supernatant conditions will be compared.
Measured: 2-3 week of recording for each supernatant condition.
Change in Dorsal Root Ganglion (DRG) neuron rheobase by fecal supernatant
DRG neurons will be incubated overnight with fecal supernatant at baseline, after low fodmap diet, fodmap subtype challenge and glucose challenge. Patch clamp recordings will be made from neurons the following day the rheobase (minimum current required to elicit an action potential in a neuron) will be measured. The mean rheobase for neurons exposed to the different supernatant conditions will be compared.
Measured: 2-3 weeks for each supernatant condition
Secondary outcomes (3)
Irritable Bowel Syndrome (IBS) Symptom Severity Score
IBS Symptom Severity Score (a score of 0 to 500, with higher scores indicating greater symptom severity) will be taken at baseline, after low fodmap diet, each fodmap subtype challenge and glucose challenge. Change in IBS Symptom Severity Score as well as number of participants with a change of at least 50 points will be analyzed.
Measured: 6 weeks
Patient-Reported Outcomes Measurement Information System Belly Pain Score
These questionnaires will be administered at baseline, after low fodmap diet, each fodmap subtype challenge and glucose challenge. The scores at each time point will be compared. The raw scores are 2-25 and this is converted to a standardized T score. Higher scores indicate a higher pain score.
Measured: 6 weeks
Microbial community composition
The chemostat cultures will be sampled after each stage (steady state, low fodmap media, fodmap subtype medias, glucose media) and analyzed
Measured: 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jul 2026
- Study start16 Mar 2026
- Primary completionMar 2030 (estimated)
- Study completionMar 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel Syndrome (IBS)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- David Reed
- Sponsor type
- University, hospital or other
- Collaborators
- Weston Family Foundation
- Responsible party
- Sponsor-investigator, David Reed, Queen's University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07688044
- Sponsor's protocol ID
- 6044324
- Status last verified
- Jul 2026
- First submitted
- 30 Jun 2026
- Last updated
- 15 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Gut Microbiota in Patient Responses to a Dietary Therapy for Abdominal Pain
- ClinicalTrials.gov ID
- NCT07688044
- Acronym / sponsor ID
- 6044324
- Conditions
- Irritable Bowel Syndrome (IBS)
- Keywords
- FODMAPs, Microbiota, Neuroactive mediators, Abdominal pain, GI pain signaling
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- David ReedUniversity, hospital or other
- Collaborators
- Weston Family Foundation
- Study start
- 16 Mar 2026 (actual)
- Primary completion
- Mar 2030 (estimated)
- Study completion
- Mar 2031 (estimated)
- First posted
- 7 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Irritable Bowel Syndrom (IBS) affects up to five percent of Canadians and has proven difficult to treat. Our research will explore how a type of dietary carbohydrate, called FODMAPS, contributes to chronic abdominal pain in irritable bowel syndrome (IBS). FODMAPs, are poorly digested carbohydrates and removing FODMAPs from the diet relieves abdominal pain in approximately half of IBS patients. Unfortunately, FODMAPs are contained in many foods, which makes it challenging for patients to remain on a low FODMAP diet for extended periods. Our proposed research will identify which subtypes of FODMAPs are most responsible for increasing pain and will tease apart whether the pain-causing effects of FODMAPs rely on the gut microbiota or not. To identify which specific type of FODMAP causes pain, IBS patients will adopt a low FODMAP diet and then individual FODMAP subtypes will be added back to their diet while monitoring changes to their pain. Stool samples will be collected from the participants to determine whether the composition of the gut microbiota or the chemicals that it produces are changed when symptoms are improved or exacerbated by manipulating FODMAP availability. In parallel studies, the microbiota of each IBS patient will be grown in specialized conditions to mimic the environment of the gut. These patient microbial communities will be exposed to the same FODMAP manipulations as the patients themselves experience. This will allow us to test whether the changes in gut microbiota composition and the chemicals produced that occur in IBS patients in response to FODMAP manipulations also occur when only the microbiota is exposed to these manipulations. Together, these studies will aim to optimize a dietary therapy for a common chronic pain condition and will provide novel insights into how diet affects the chemicals the gut microbiota produces that contribute to abdominal pain.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| FODMAP Challenge | Experimental | Other: FODMAP ChallengeParticipants will be on a low fodmap diet (LFD) for a total of 6 weeks. After two weeks on LFD, each participant whose IBS-symptom severity score was reduced by 50 points will be deemed a responder, and will proceed to the next stage of the study. This will entail each participant remaining on the LFD while beginning 4 four-day individual challenges every 7 days consisting of 3 FODMAP subgroup challenges (galacto-oligosaccahride, fructan, and sorbitol) and 1 glucose challenge as a non-FODMAP carbohydrate control. Each challenge will comprise of a 4-day challenge with one of the three FODMAP subgroups or a glucose challenge (as a negative control) followed by a 3-day washout period with any residual symptoms resolved while remaining on the LFD prior to the next challenge. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Adults aged 18-70 with IBS (Rome IV (now V) criteria)
- PROMIS belly pain score >12
Key exclusion criteria (12 listed)
- Concurrent significant organic GI pathology (i.e. celiac, IBD, etc.) as some symptoms may be related to their disease and not IBS.
- Concurrent systemic disease and/or laboratory abnormalities considered by investigators to be risky or that could interfere with data collection.
- Major gastrointestinal surgery (e.g. Roux en y, bowel resection) as symptoms may be related to previous surgery rather than IBS.
- Body mass index above 35 kg/m2 as it is unknown how mediators in the GI tract that may be involved in pain signaling in the gut are affected by obesity.
- History of active cancer in the last 5 years, other than basal cell cancer as the treatment may have impacted the GI tract.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| FODMAP ChallengePrior to beginning the LFD, each participant will provide a stool sample. This will be used to inoculate a continuous culture system (chemostat) as these vessels maintain fecal microbial communities under controlled anaerobic conditions. After reaching steady state in culture media with FODMAPs (7 days), the media will be switched to a low FODMAP media for 7 days. Then each vessel will be exposed to the same FODMAP subgroups challenges and glucose challenge as the participants for 3 days. At each stage (i.e., steady state, after low fodmap media, after each challenge) culture supernatant will be collected. This supernatant will be used to test its neurophysiological effects on pain sensing neurons in pre-clinical studies. In addition, participants will provide a stool sample at each stage. Fecal supernatants will be produced from these samples and the neurophysiological effects of the fecal supernatants will be tested in pre-clinical studies. | Other | FODMAP Challenge |
Primary outcome
Change in Dorsal Root Ganglion (DRG) neuron rheobase by chemostat supernatant
Time frame: 2-3 week of recording for each supernatant condition.
DRG neurons will be incubated overnight with chemostat supernatant after steady state, low fodmap media, fodmap subtype media and glucose media. Patch clamp recordings will be made from neurons the following day the rheobase (minimum current required to elicit an action potential in a neuron) will be measured. The mean rheobase for neurons exposed to the different supernatant conditions will be compared.
Change in Dorsal Root Ganglion (DRG) neuron rheobase by fecal supernatant
Time frame: 2-3 weeks for each supernatant condition
DRG neurons will be incubated overnight with fecal supernatant at baseline, after low fodmap diet, fodmap subtype challenge and glucose challenge. Patch clamp recordings will be made from neurons the following day the rheobase (minimum current required to elicit an action potential in a neuron) will be measured. The mean rheobase for neurons exposed to the different supernatant conditions will be compared.
3 secondary outcomes
Irritable Bowel Syndrome (IBS) Symptom Severity Score
Time frame: 6 weeks
Patient-Reported Outcomes Measurement Information System Belly Pain Score
Time frame: 6 weeks
Microbial community composition
Time frame: 6 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing FODMAP Challenge in people with Irritable Bowel Syndrome (IBS), run by David Reed at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Dorsal Root Ganglion (DRG) neuron rheobase by chemostat supernatant (time frame: 2-3 week of recording for each supernatant condition.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jul 2026.