Is the gut microbiome of importance in fibromyalgia? A critical review of emerging evidence

Fibromyalgia (FM) is a multifaceted chronic pain syndrome, predominantly affecting women, and characterised by a constellation of symptoms including diffuse musculoskeletal pain, fatigue, cognitive impairment and poor sleep quality. Its complex pathophysiology likely involves genetic, environmental and psychosocial factors. Recent studies have raised the possibility that the gut microbiome may influence FM symptoms via the gut-brain axis, although this hypothesis remains unconfirmed. This review aims to explore potential associations between gut microbiome alterations, nutrition, and FM, with particular attention to the limitations of current evidence. While certain studies have reported differences in the gut microbiota composition of patients with FM, these findings are preliminary and often derive from small, heterogeneous cohorts. Likewise, faecal microbiota transplantation studies in animals and limited human trials suggest a possible link to pain sensitivity, but further validation is needed.Nutritional interventions, including prebiotics, probiotics and specific dietary strategies, have shown early promise in modulating gut microbiota and alleviating FM symptoms. Nutrients such as magnesium, selenium and omega-3 fatty acids, as well as antioxidant compounds, may influence pain and inflammation pathways, but definitive clinical recommendations are lacking. Given the emerging nature of this field, larger and better-controlled studies are required to clarify the role of the gut microbiome and nutrition in FM. A multidisciplinary management strategy, integrating nutritional approaches cautiously and based on individual profiles, may offer benefits, although no standard therapeutic guidelines currently exist.