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

Study Overview
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Brief Summary
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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).

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

Conditions
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Fibromyalgia, Diet, Gluten-Free

Intervention / Treatment
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* Behavioral: Low-FODMAP diet
* Behavioral: Gluten-free Diet
* Behavioral: Control group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 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. Exclusion Criteria: 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.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low-FODMAP Diet<br>Participants 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). | Behavioral: Low-FODMAP diet<br>* Participants will be instructed to maintain their usual diet, while eliminating all dietary gluten.<br>|
| Experimental: Gluten-Free Diet<br>Participants will be instructed to maintain their usual diet, while eliminating all dietary gluten. | Behavioral: Gluten-free Diet<br>* Participants will be instructed to maintain their usual diet, while eliminating all dietary gluten.<br>|
| Other: Control<br>Patients of this group will be asked to adhere to their regular, daily diet. | Behavioral: Control group<br>* Patients of this group will have dietary consultation but will not change their regular diet for the period of the study.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in gut microbiome composition in response to dietary intervention | Genome structure, structural variants - Differential abundance analysis will be performed using 16S rRNA. | Four weeks after the initiation of the new diet compared to baseline. | 
| 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. | Four weeks after the initiation of the new diet compared to baseline. | 
| 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. | Four weeks after the initiation of the new diet compared to baseline. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. | Four weeks after the initiation of the new diet compared to baseline. | 
| The Fibromyalgia Impact Questionnaire (FIQ) score | A 10 items questionnaire evaluating physical functioning, work difficulty, pain, fatigue, morning tiredness, stiffness, anxiety and depression. | Four weeks after the initiation of the new diet compared to baseline. | 
| Hospital Anxiety and Depression Scale (HADS) score | A 14-items questionnaire assessing the level of depression and anxiety. | Four weeks after the initiation of the new diet compared to baseline. | 
| The Pittsburg Sleep Quality Index scores | An 11 item sleep quality evaluation questionnaire. | Four weeks after the initiation of the new diet compared to baseline. | 
| ROME IV criteria for irritable bowel syndrome | Four yes-or-no items | Four weeks after the initiation of the new diet compared to baseline. |