The gut microbiota is closely associated with spinal cord injury (SCI). Dihydromyricetin (DHM), a potent anti-inflammatory compound with neuroprotective properties, has been shown to improve outcomes in various diseases. However, the role of gut microbiota mediating the mechanism neuroprotective effects of DHM in SCI is unknown. Male Sprague-Dawley rats were randomly divided into three groups: SHAM, SCI, and DHM group. Motor function was assessed using the cylinder rearing test, and alterations in gut microbiota composition and metabolites were analyzed via 16S rRNA sequencing. Subsequently, Western blotting and immunofluorescence staining were employed to evaluate intestinal barrier integrity, as well as changes in proteins associated with the TLR4/NF-κB pathway and NLRP3/Caspase-1. Finally, fecal microbiota transplantation experiments were conducted to elucidate the necessity of gut microbiota in mediating the anti-inflammatory effects of DHM. DHM exhibits a therapeutic effect by attenuating the severity of pathological SCI and promoting motor function recovery. Notably, DHM restored a balanced microbiota pattern by increasing the relative abundance of Actinobacteria and Bacteroidetes, while concurrently decreasing that of Proteobacteria. Furthermore, DHM promoted intestinal barrier recovery, reduced blood lipopolysaccharide (LPS) levels, and suppressed the activation of the TLR4/NF-κB pathway and reduced the activity of the NLRP3/Caspase-1 inflammasome, thereby effectively decreasing the subsequent release of inflammatory factors in spinal cord tissue. Furthermore, the results from the two FMT groups demonstrated that the gut microbiota serves as a critical target for DHM to exert its anti-inflammatory effects. The results of this study demonstrate that restoring microbial balance, repairing intestinal barrier integrity, reducing serum LPS levels, and suppressing the TLR4/NF-κB pathway as well as NLRP3/Caspase-1 inflammasome activity constitute the key regulatory mechanisms underlying the neuroprotective effects of DHM following SCI, thereby opening up possibilities for a novel microbiome-directed therapeutic approach to SCI.
Yang et al. (Sat,) studied this question.