Danggui Buxue Decoction Attenuates Staphylococcus aureus-Induced Mastitis in Mice Associated with Gut Microbiota Remodeling, Blood–Milk Barrier Protection, and Inflammatory Suppression

This study investigated the protective effects of DBD against Staphylococcus aureus (S. aureus)-induced mastitis in mice and explored whether these effects were associated with gut microbiota alterations, blood–milk barrier integrity, and inflammatory signaling. A lactating mouse model of mastitis was established, and the effects of DBD were evaluated using HPLC, histopathological analysis, ELISA, qRT-PCR, Western blotting, immunofluorescence, and 16S rRNA sequencing. The results showed that DBD significantly reduced bacterial loads in mammary tissues, decreased the expression of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, and alleviated inflammatory cell infiltration and tissue damage. Moreover, DBD upregulated the expression of tight junction proteins and improved the integrity of the blood–milk barrier. DBD treatment was also associated with alterations in gut microbiota composition, as reflected by changes in the relative abundance of several bacterial taxa. In addition, DBD inhibited the activation of the NF-κB/NLRP3 and MAPK inflammatory signaling pathways. Collectively, these findings indicate that DBD alleviates S. aureus-induced mastitis accompanied by alterations in gut microbiota composition, suppressing inflammatory responses, and repairing the blood–milk barrier, suggesting its potential as a therapeutic agent for mastitis.