Fibromyalgia and the Microbiome
In 2019, researchers in Montreal were the first to demonstrate a link between alteration of the gut microbiome and fibromyalgia.1
Background
Fibromyalgia is a chronic disorder that causes pain all over the body, fatigue, sleep disturbance, and altered cognition, which significantly impair the lives of approximately 2-4% of the Canadian adult population. There is no specific test for fibromyalgia, so diagnosis occurs when there is widespread pain for more than three months with no underlying medical condition that could cause the pain. Treatment focuses on pain management, physical therapy, occupational therapy, lifestyle management, and counselling.
In recent years, research has focused on the critical role that the gut microbiota plays in several conditions, including digestive, cardiovascular, metabolic, and psychiatric disorders. This is providing increased understanding of the brain-gut axis, which is the relationship between the central nervous system and the gut microbiota, and how it affects pain perception and processing.
Results from several animal and human studies have shown that the gut microbiota has a pivotal role in the development of pain arising from internal organs (visceral pain). Unfortunately, evidence for disorders that involve pain arising from nerve endings of the skin, muscles, and soft tissues (non-visceral pain), such as fibromyalgia, is scarce. However, some studies show that those who have fibromyalgia often have a comorbidity of irritable bowel syndrome, which researchers speculate may point to a common dysregulation in the brain-gut axis.2
Study Details
For this analysis, the researchers classed participants into two main groups – those with fibromyalgia and those without it:
- 77 women with a fibromyalgia diagnosis, 30-60 years of age
- 79 control participants, which had sub-groups consisting of a) first-degree adult female relatives of patients in the study, as genetic controls b) household members of patients in the study, as environment controls, women and men 30-70 years of age, and c) unrelated healthy women 30-60 years of age
Exclusion criteria included major chronic illness, antibiotic treatment in the preceding two months, any acute illness in the preceding month, change in regularly taken medication in the preceding month, and substantial dietary alterations in the preceding month.
A physician specializing in pain management interviewed all patient and control participants, collecting a wide range of data, both in-person and via questionnaires, such as demographics, body measurements, medications, dietary intake, physical activity, alcohol intake, smoking, symptom severity, physical functioning, sleep quality, anxiety and depression, and pain location. Researchers made note of comorbidities and all medications participants were taking. All provided a stool sample for laboratory analysis. A registered dietitian also interviewed the participants and instructed them on how to monitor their dietary intake accurately.
Findings
Investigators found that there were no significant differences in sample diversity among participants. However, when analyzing the stool samples for microbiota DNA, they detected the highest amounts of microbiome variance in participants diagnosed with fibromyalgia. They discovered that the gut microbiota of fibromyalgia patients had a distinctive profile, characterized by 19 different species, each of which were detected to be either higher or lower than in the healthy control group. Bacteria such as Flavonifractor plautii and Parabacteroides merdae occurred in higher amounts, whereas bacteria such as Faecalibacterium prausnitzii, one of the most abundant and important good bacteria of the human gut microbiota, occurred in lesser quantities.
While results portray that participants with fibromyalgia have an altered gut microbiome composition, the researchers acknowledge that although their study is the first of its kind, it was a small sampling, and they encourage more research to explore this interesting area.