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FibromyalgiaNCT05329571

The Effects of Dietary Changes on Gut-bacteria and Fibromyalgia Symptoms

A study testing Low-FODMAP diet and Gluten-free Diet in people with Fibromyalgia and Diet, Gluten-Free, run by McGill University Health Centre/Research Institute of the McGill University Health Centre at 1 site in Canada.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of this study is to evaluate the efficacy of two diets - gluten-free and low-FODMAP diet- in relieving symptoms of fibromyalgia, and study whether these changes could be associated with changes in the gut microbiome (gut bacteria). Read more about this study

Who is it for?
Ages 18 years and older, women only
Conditions the study is for
Fibromyalgia, Diet, Gluten-Free
What is being tested?
Low-FODMAP diet and Gluten-free Diet
Could I receive a placebo?
No, everyone receives an active treatment
How many people
59 participants
Where
1 siteCanada
Study dates
12 Mar 2021to 6 Jul 2022
Phase
Interventional
Are there results?
None posted in the registry

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 years and older
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Women over the age of 18, diagnosed with FM.
  • Chronic widespread pain index >= 9 and pain intensity >= 6.
  • Able to read and write in either French or English.

Who cannot join

  • Any major illness (e.g. malignancy, active inflammatory disease, metabolic disease, etc.)
  • Inflammatory bowel disease.
  • Severe depression (HADS score for depression > 10).
  • Current use of LFD or GFD.
  • Pregnancy
  • Vegan diet
  • The inclusion/exclusion criteria were set to reduce the risk of confounding factors that could affect gut microbiota composition. To date, information on microbiome alterations in individuals with fibromyalgia is only available for female patients, and thus recruitment will be limited to women.

Trial locations and contacts

1 site in 1 country.

Canada1 site

  • Alan Edwards Pain Management Unit - Montreal General Hospital

    Montreal, Quebec, H3G 1A4

Other trials in Canada

About this study

Official title: Microbiome Correlates of Dietary Interventions in Patients With Fibromyalgia and Their Association With Symptom Modification

The purpose of this study is to evaluate the efficacy of two diets - gluten-free and low-FODMAP diet- in relieving symptoms of fibromyalgia, and study whether these changes could be associated with changes in the gut microbiome (gut bacteria).

Being tested
Low-FODMAP diet, Gluten-free Diet, Control group
Medical subject headings
Fibromyalgia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Low-FODMAP dietBehavioural

    Participants will be instructed to maintain their usual diet, while eliminating all dietary gluten.

  • Gluten-free DietBehavioural

    Participants will be instructed to maintain their usual diet, while eliminating all dietary gluten.

  • Control groupBehavioural

    Patients of this group will have dietary consultation but will not change their regular diet for the period of the study.

Study groups in NCT05329571
Study groupRoleWhat they receive
Low-FODMAP DietExperimentalParticipants will be instructed to maintain their usual diet, while eliminating FODMAPs (A subgroup of carbohydrates are considered fermentable, given the lack of suitable hydrolase enzymes in the colon, required for their digestion and absorption, thus making them available for fermentation).
Receives: Behavioral: Low-FODMAP diet
Gluten-Free DietExperimentalParticipants will be instructed to maintain their usual diet, while eliminating all dietary gluten.
Receives: Behavioral: Gluten-free Diet
ControlOtherPatients of this group will be asked to adhere to their regular, daily diet.
Receives: Behavioral: Control group

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Changes in gut microbiome composition in response to dietary intervention

    Genome structure, structural variants - Differential abundance analysis will be performed using 16S rRNA.

    Measured: Four weeks after the initiation of the new diet compared to baseline.

  2. Changes in stool microbiota-related metabolites affecting host physiology, in response to dietary intervention.

    Metabolomics analysis will be performed (Metabolon, USA) - targeted metabolomic for bile acids and SCFA analysis.

    Measured: Four weeks after the initiation of the new diet compared to baseline.

  3. Changes in blood microbiota-related metabolites, affecting host physiology, in response to dietary intervention

    Metabolomics analysis will be performed (Metabolon, USA) - targeted metabolomic for bile acids and SCFA analysis.

    Measured: Four weeks after the initiation of the new diet compared to baseline.

Secondary outcomes (5)

  1. The Fibromyalgia Survey Diagnostic Criteria and Severity Scale (FSDC) scores.

    assessing symptom severity, pain distribution, fatigue, sleep quality and cognitive and somatic complaints in fibromyalgia patients.

    A questionnaire assessing symptom severity, pain distribution, fatigue, sleep quality and cognitive and somatic complaints in fibromyalgia patients.

    Measured: Four weeks after the initiation of the new diet compared to baseline.

  2. The Fibromyalgia Impact Questionnaire (FIQ) score

    A 10 items questionnaire evaluating physical functioning, work difficulty, pain, fatigue, morning tiredness, stiffness, anxiety and depression.

    Measured: Four weeks after the initiation of the new diet compared to baseline.

  3. Hospital Anxiety and Depression Scale (HADS) score

    A 14-items questionnaire assessing the level of depression and anxiety.

    Measured: Four weeks after the initiation of the new diet compared to baseline.

  4. The Pittsburg Sleep Quality Index scores

    An 11 item sleep quality evaluation questionnaire.

    Measured: Four weeks after the initiation of the new diet compared to baseline.

  5. ROME IV criteria for irritable bowel syndrome

    Four yes-or-no items

    Measured: Four weeks after the initiation of the new diet compared to baseline.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted15 Apr 2022
  2. Study start12 Mar 2021
  3. Primary completion15 Jun 2022
  4. Study completion6 Jul 2022

Resources

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
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
59 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05329571
Sponsor's protocol ID
Diet-FM/2020-6134
Status last verified
Oct 2026
First submitted
22 Feb 2022
Last updated
26 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Bauer KC, Huus KE, Finlay BB. Microbes and the mind: emerging hallmarks of the gut microbiota-brain axis. Cell Microbiol. 2016 May;18(5):632-44. doi: 10.1111/cmi.12585. Epub 2016 Mar 31.

    PubMed 26918908

  • Minerbi A, Gonzalez E, Brereton NJB, Anjarkouchian A, Dewar K, Fitzcharles MA, Chevalier S, Shir Y. Altered microbiome composition in individuals with fibromyalgia. Pain. 2019 Nov;160(11):2589-2602. doi: 10.1097/j.pain.0000000000001640.

    PubMed 31219947

  • Thaiss CA, Itav S, Rothschild D, Meijer MT, Levy M, Moresi C, Dohnalova L, Braverman S, Rozin S, Malitsky S, Dori-Bachash M, Kuperman Y, Biton I, Gertler A, Harmelin A, Shapiro H, Halpern Z, Aharoni A, Segal E, Elinav E. Persistent microbiome alterations modulate the rate of post-dieting weight regain. Nature. 2016 Dec 22;540(7634):544-551. doi: 10.1038/nature20796. Epub 2016 Nov 24.

    PubMed 27906159

  • Tong M, Li X, Wegener Parfrey L, Roth B, Ippoliti A, Wei B, Borneman J, McGovern DP, Frank DN, Li E, Horvath S, Knight R, Braun J. A modular organization of the human intestinal mucosal microbiota and its association with inflammatory bowel disease. PLoS One. 2013 Nov 19;8(11):e80702. doi: 10.1371/journal.pone.0080702. eCollection 2013.

    PubMed 24260458

  • Zhang X, Zhang D, Jia H, Feng Q, Wang D, Liang D, Wu X, Li J, Tang L, Li Y, Lan Z, Chen B, Li Y, Zhong H, Xie H, Jie Z, Chen W, Tang S, Xu X, Wang X, Cai X, Liu S, Xia Y, Li J, Qiao X, Al-Aama JY, Chen H, Wang L, Wu QJ, Zhang F, Zheng W, Li Y, Zhang M, Luo G, Xue W, Xiao L, Li J, Chen W, Xu X, Yin Y, Yang H, Wang J, Kristiansen K, Liu L, Li T, Huang Q, Li Y, Wang J. The oral and gut microbiomes are perturbed in rheumatoid arthritis and partly normalized after treatment. Nat Med. 2015 Aug;21(8):895-905. doi: 10.1038/nm.3914. Epub 2015 Jul 27.

    PubMed 26214836

  • Lowry E, Marley J, McVeigh JG, McSorley E, Allsopp P, Kerr D. Dietary Interventions in the Management of Fibromyalgia: A Systematic Review and Best-Evidence Synthesis. Nutrients. 2020 Aug 31;12(9):2664. doi: 10.3390/nu12092664.

    PubMed 32878326

Questions about this trial

What is this clinical trial studying?

A study testing Low-FODMAP diet and Gluten-free Diet in people with Fibromyalgia and Diet, Gluten-Free, run by McGill University Health Centre/Research Institute of the McGill University Health Centre 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 3 inclusion and 7 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: finished, as of the sponsor's last update on 26 Oct 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in gut microbiome composition in response to dietary intervention (time frame: Four weeks after the initiation of the new diet compared to baseline.). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05329571, which also lists 6 linked publications.

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 26 Oct 2026.

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