Orally Administered <i>Bacillus licheniformis</i> F0726 Attenuates MPTP/P-Induced Neurodegeneration by Modulating Gut Microbiota and Suppressing Inflammatory Responses

Extensive studies have shown that Parkinson's disease (PD) is associated with disruption in the gut microbiota. <i>Bacillus licheniformis</i> has attracted the attention of researchers due to its function in regulating the composition of intestinal microbiota. This study investigated the neuroprotective effects of orally administered <i>B. licheniformis</i> F0726 in an MPTP/P-induced mice model of PD. The results showed that <i>B. licheniformis</i> F0726 significantly alleviated MPTP/P-induced motor dysfunction and depletion of dopamine-containing neurons. Notably, <i>B. licheniformis</i> F0726 alleviated neuroinflammation by inhibiting glial cell activation and reducing serum pro-inflammatory cytokine levels. Furthermore, 16S rRNA sequencing revealed that intervention with <i>B. licheniformis</i> F0726 alleviated the gut dysbiosis. Crucially, <i>B. licheniformis</i> F0726 significantly increased the level of short-chain fatty acids, which are key signaling molecules of the gut-brain axis. In conclusion, <i>B. licheniformis</i> F0726 may alleviate neurodegenerative lesions in PD mice by modulating the gut microbiota and suppressing inflammatory responses.