Paeoniflorin (PF), the primary bioactive component of Paeonia plants, exhibits neuroprotective and anti-inflammatory activities. However, its potential role in alcohol-induced depression (AID) through the microbiota-metabolite-brain axis remains unclear. This study aimed to investigate the antidepressant effect of PF and its underlying gut-brain communication mechanisms. A mouse model of chronic alcohol exposure was established and treated with PF. Behavioral tests (SPT, FST, TST, OFT) and histopathological examinations were conducted. Network pharmacology and molecular docking were used to predict targets, followed by experimental validation of microglial activation and the NF-κB/NLRP3 pathway. Multi-omics approaches including 16S rRNA sequencing and untargeted metabolomics were applied to analyze gut microbiota and fecal metabolites. PF significantly alleviated depressive-like behaviors, hippocampal damage, and oxidative stress, while restoring monoamine neurotransmitter levels. It suppressed microglial activation and the NF-κB/NLRP3 inflammasome cascade. Furthermore, PF reshaped gut microbiota composition (reducing Rikenellaceae and Prevotellaceae) and modulated metabolite profiles and upregulated the neuroprotective metabolite niacin, along with other identified metabolites. These findings demonstrate that PF alleviates Alcohol-Induced Depression (AID) by remodeling the microbiota-metabolite-brain axis and inhibiting neuroinflammation. The study highlights PF's therapeutic potential for alcohol-related mood disorders and underscores the gut-brain axis as a critical target for antidepressant therapy.
