Fecal Microbiota Transplantation Improves Clinical Symptoms of Fibromyalgia: An open-label, Randomized, Nonplacebo-Controlled Study

Fibromyalgia (FM) is a complex and poorly understood disorder characterized by chronic and widespread musculoskeletal pain, of which the etiology remains unknown. Now, the disorder of the gut microbiome is considered as one of the main causes of FM. This study was aimed to investigate the potential benefits of fecal microbiota transplantation (FMT) in patients with FM. A total of 45 patients completed this open-label randomized, nonplacebo-controlled clinical study. The Numerical Rating Scale (NRS) scores in the FMT group were slightly lower than the control group at 1 month (P> 0.05), and they decreased significantly at 2, 3, 6, and 12 months after treatment (P < 0.001). Besides, compared with the control group, the Widespread Pain Index (WPI), Symptom Severity (SS), Hospital Anxiety and Depression Scale (HADS) and Pittsburgh Sleep Quality Index (PSQI) scores were significantly lower in the FMT group at different time points (P < 0.001). After 6 months of treatment, there was a significant increase in serotonin (5-HT) and gamma-aminobutyric acid (GABA) levels (P < 0.001), while glutamate levels significantly decreased in the FMT group (P < 0.001). The total effective rate was higher in the FMT group (90.9%) compared to the control group (56.5%) after 6 months of treatment (P < 0.05). FMT can effectively improve the clinical symptoms of FM. With the close relations between the changes of neurotransmitters and FM, certain neurotransmitters may serve as a diagnostic marker or potential target for FM patients. Perspective Fecal microbiota transplantation (FMT) is a novel therapy that aims to restore the gut microbial balance and modulate the gut-brain axis. It is valuable to further explore the therapeutic effect of FMT on FM. Furthermore, certain neurotransmitters may become a diagnostic marker or a new therapeutic target for FM patients.