Investigating the association between the symptoms of women with Fibromyalgia, Digestive function, and markers of the microbiota of the Gastrointestinal Tract (The FIDGIT Study): study protocol

BACKGROUND

Fibromyalgia a common idiopathic condition affecting around 1.4% of adults globally. Its signature symptom is chronic widespread pain, with a constellation of somatic and psychological symptoms. Fibromyalgia is associated with significant reductions in quality of life, yet to date there is no biochemical marker for its diagnosis. Previous studies have indicated a strong association with gastrointestinal dysfunction, and more recently, alterations to the gut microbiome. No studies have examined the inter-relationship between fibromyalgia, gastrointestinal dysfunction, and the microbiome. This prospective observational case-controlled study will gather data on gastrointestinal function, dietary intake, fermentation patterns of ingested carbohydrates, and symptoms commonly associated with fibromyalgia. These will be evaluated alongside human gene expression and metatranscriptomic analysis of the oral and faecal microbiome.

METHODS

Adult women aged ≥18 years diagnosed with fibromyalgia and/or meeting ACR 2016 criteria, and healthy family or age-matched controls will be recruited from the community. From consenting participants, we will collect detailed survey information and samples of blood, urine, stool, saliva, and breath.

DISCUSSION

This is the first prospective study examining interactions between digestive function, human gene expression, and the gut microbiome together with general, and fibromyalgia-specific, symptoms experienced by New Zealand women. This exploration will allow an in-depth understanding of clinically relevant factors that are associated with fibromyalgia and will guide further research and contribute to improved management of this poorly understood condition.

TRIAL REGISTRATION

The study was approved by the New Zealand Health and Disability Committee (HDEC) (ref: 20/CEN/197) and registered with the Australia and New Zealand Clinical Trials Registry (ANZCTR), registration number ACTRN12620001337965. Written consent will be obtained after providing participants with detailed information about the procedures. Access to data will be restricted to the immediate research team, and all samples and survey data will be deidentified and coded before analysis.

Fibromyalgia: Prevalence, epidemiologic profiles and economic costs

Fibromyalgia is an idiopathic chronic condition that causes widespread musculoskeletal pain, hyperalgesia and allodynia. This review aims to approach the general epidemiology of fibromyalgia according to the most recent published studies, identifying the general worldwide prevalence of the disease, its basic epidemiological profiles and its economic costs, with specific interest in the Spanish and Comunidad Valenciana cases. Fibromyalgia affects, on average, 2.10% of the world's population; 2.31% of the European population; 2.40% of the Spanish population; and 3.69% of the population in the Comunidad Valenciana. It supposes a painful loss of the quality of life of the people who suffer it and the economic costs are enormous: in Spain is has been estimated at more than 12,993 million euros annually.