Bidirectional communication between spinal cord injury and gut microbiota, from the bench to the bedside

Spinal cord injury (SCI) is a type of central nervous system damage that often results in motor, sensory, and autonomic dysfunction, and can lead to death, with currently no effective treatment available. As research on the microbiome in central nervous system disorders progresses, the role of gut microbiota in spinal cord injury has garnered significant attention. Spinal cord injury disrupts intestinal function and triggers an imbalance in gut microbiota, while metabolites produced by gut microbiota can cross the blood-spinal cord barrier into the central nervous system, exacerbating neuroinflammation in the spinal cord. The relationship between gut microbiota dysbiosis and spinal cord injury is bidirectional. In recent years, the proposal of the 'gut microbiota-gut-spinal cord' axis theory has led to increased interest in the impact of gut microbiota on spinal cord injury. Gut microbiota not only serve as biomarkers for the severity of spinal cord injury but also represent potential therapeutic targets. Current research primarily focuses on the alterations in gut microbiota following spinal cord injury and the potential effects of microbiota-derived metabolites-such as aryl hydrocarbon receptor agonists and short-chain fatty acids-on secondary inflammatory responses post-injury. Although numerous studies have utilized various approaches to modulate gut microbiota to promote functional recovery after spinal cord injury, standardized and effective clinical treatments remain elusive. This review synthesizes laboratory and clinical perspectives on the mechanisms underlying the interaction between spinal cord injury and gut microbiota, aiming to provide novel insights for the therapy of spinal cord injury.