Fibromyalgia: reliable diagnosis soon possible thanks to the microbiota?

A recent article may put an end to misdiagnosis for thousands of women suffering from fibromyalgia, a disease characterized by chronic diffuse pain combined with intense fatigue and various issues, including sleep and mood disorders. There are no “markers” for making a diagnosis, such as a lesion in the body (unlike a fracture of the tibia, confirmed via a simple X-ray) or a laboratory parameter (unlike blood sugar levels, which indicate diabetes). This directly affects the quality of life of fibromyalgia patients.

Fibromyalgia: focus on 5 bacteria

New research may mark a turning point. Starting point: studying the differences between the gut microbiota compositions of 42 fibromyalgia patients and 42 other healthy women. Result: of the 16 various bacterial families present in the women with fibromyalgia, three were low while two others seemed quite high. Now, these 5 bacterial species have one thing in common: they transform molecules called primary bile acids (sidenote: Bile acids Bile acids facilitate digestion and absorption of lipids in the intestine. They also exercise hormonal functions and are involved in various metabolic processes. The gut microbiota will modify the bile acids. In return the various bile acids will have an impact on its composition. Staels B, Fonseca VA. Bile acids and metabolic regulation: mechanisms and clinical responses to bile acid sequestration. Diabetes Care. 2009;32 Suppl 2(Suppl 2):S237-S245.  Li R, Andreu-Sánchez S, Kuipers F, Fu J. Gut microbiome and bile acids in obesity-related diseases. Best Pract Res Clin Endocrinol Metab. 2021;35(3):101493.  ) into secondary bile acids (SBA).

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Furthermore, the authors observed differences in the concentrations of certain SBAs in the blood of patients suffering from fibromyalgia – e.g., α-muricholic acid levels were on average 5 times lower in women with this condition! In addition, the lower the α-muricholic acid levels, the greater the pain, fatigue and symptom severity scores. In short, there is a link between an intestinal imbalance and the blood levels of a specific bile acid, which are in turn associated with symptom severity in patients with fibromyalgia.

So can we expect a diagnostic test in the near future?

As a direct consequence of these observations, it may be possible to simply measure the concentration of these small acids, by means of a blood test, to accurately detect people suffering from fibromyalgia. This would enable us to objectify diagnosis of this disease. The model developed by the authors seems promising, showing accuracy of 91.7%. This is enough to raise hopes of a reliable diagnosis becoming available in the future, putting an end to the ordeal for thousands of women.