As many as 4% of women may suffer from fibromyalgia, a disorder that causes flares of pain in the muscles and soft tissues of the body. It can also cause sleep problems, depression, fatigue, and headaches. The pain can vary, and may be worsened by certain conditions like anxiety, stress, or cold and damp weather. Fibromyalgia is tough to diagnose because there are no biomarkers that are known to reliably identify the condition. The causes are also unknown, but research has suggested that it may be related to the immune system or autoimmunity.
Scientists have now discovered that when gut microbes from fibromyalgia patients were transplanted into a mouse model, the mice began to exhibit changes that mimic fibromyalgia. The mice experienced changes in metabolism, immunity, and pain. The findings have been reported in Neuron.
Gastrointestinal disorders are common in fibromyalgia patients. In recent years, scientists have shown that the community of microbes in the human gut can have a major impact on our health and well-being. Researchers are also starting to identify specific microbes or the metabolites they make, which can have certain effects on human health.
The composition of the gut microbiome of fibromyalgia patients has been shown to differ from unaffected individuals.
The researchers transplanted gut microbes from female fibromyalgia patients (that had been obtained from fecal samples), and gut microbes from unaffected women into recipient mice that lacked gut microbiomes of their own. The mice were assessed in different ways, including with single-cell RNA sequencing, and dorsal root ganglia calcium imaging that can illuminate nerve activity.
This work showed that the mice that got fecal samples from fibromyalgia patients displayed many types of spontaneous pain, such as heat, cold, and touch hypersensitivity, along with muscle pain. This happened within only four weeks of receiving the fecal transplant.
There were also many changes in the gut microbiomes of these mice. Bile acid and amino acid metabolism also changed; the density of some nerve fibers was reduced; and pain responses were reduced as well.
In another part of the study, a small group of fourteen female fibromyalgia patients received oral doses of microbiome samples from healthy female donors. These doses were given after a bowel cleaning procedure. Pain hypersensitivity was reduced in the fibromyalgia patients who were recipients of healthy donor microbiome samples. The disease was not eliminated, but symptoms were significantly reduced. The researchers also confirmed that donor gut bacteria had colonized the recipients' guts.
More research will be needed to confirm and advance these findings, and to potentially identify the exact microbes that may be influencing, or possibly causing or relieving fibromyalgia. But the study has indicated that this is a promising avenue of inquiry that could one day open up new treatment options for fibromyalgia patients.
Sources: Medical Express, Neuron