Fibromyalgia is a chronic condition that causes widespread pain, fatigue, and other symptoms, significantly affecting quality of life. Unfortunately, there are few effective treatments available. Recently, medical cannabis has gained attention as a potential treatment, leading many countries to approve its use for fibromyalgia. However, its success is limited-only about 25% of patients experience meaningful pain relief, and side effects like dizziness or fatigue are common. Not everyone responds to medical cannabis the same way, and researchers think this variability may partly be explained by differences in the gut microbiome-the community of bacteria and other microorganisms living in our digestive system. These microbes are known to influence various aspects of health, including pain and how the body processes medications. Our research focuses on understanding the link between the gut microbiome and fibromyalgia. We propose a study where 150 fibromyalgia patients will be treated with either cannabis oil or a placebo in a double-blind trial. By analyzing their symptoms and gut microbiome, we hope to identify patterns that could predict who will benefit most from cannabis treatment. If successful, this research could lead to more personalized and effective treatment options for fibromyalgia.

This study aims to explore the potential association between the composition of the gut microbiome and the individual response to cannabis oil in individuals with fibromyalgia. We propose a double-blinded randomized controlled trial, where 150 patients with fibromyalgia will be treated with either a careful titration of cannabis oil (5% THC, 5% CBD) or placebo with an allocation ratio of 4:1. Patient reported outcomes, quantitative sensory testing and gut microbiome and metabolome composition will be evaluated at baseline and during treatment. Subjective and objective clinical outcomes will be compared to baseline and end-of-study gut microbiome composition and metabolomic profile.

Inclusion Criteria:

• Adult men and women aged 30 years and over.
• Diagnosis of fibromyalgia confirmed according to the 2016 diagnostic criteria by a pain specialist, with relevant symptoms lasting 12 months or more.
• An average reported pain ≥ 6 during the preceding week.
• Eligible for cannabis at the discretion of the treating physician.
• Has remained symptomatic despite receiving standard care for fibromyalgia including analgesics, anti-depressants (tricyclic and SNRI) and anti-epileptic agents.

Exclusion Criteria:

• Patients who have used cannabis during the preceding month.
• Any significant comorbid condition at the discretion of the PI (e.g. inflammatory arthritis, inflammatory bowel disease, cancer).
• Personal or family history of psychotic disorders.
• Current or past anxiety disorder.
• Any uncontrolled psychiatric pathology.
• Current or history of substance addiction or abuse.
• Diagnosed dementia or cognitive impairment.
• Personal history of cardiovascular disease.
• Pregnancy, lactation or intention to conceive.
• Known allergy to any of the cannabis oil ingredients.
• Patients with a history of seizure disorder (excluding childhood febrile convulsions) or epilepsy.
• Active liver disease.
• Any contraindication to the use of MC.
• Inflammatory Bowel Disease (IBD).

Study protocol, raw data and analyses will be made available once the data analysis is complete and the study results are ready for peer review.

Estimated May 2027 for unlimited time.

All non identified data will be made publicly available.