Synthesis and long-term antibacterial performance of nano-montmorillonite-loaded polymyxin B (NMMT@PMB) against Salmonella in an ex vivo study

) Salmonella typhimurium, the nanocarrier demonstrated sustained long‑term antibacterial activity over time. The antibacterial mechanism was the disruption of bacterial membrane integrity. Additionally, ex vivo results demonstrated that NMMT@PMB regulated the microbial community composition, increasing the relative abundance of probiotic bacteria (from 72.34% to 75.20%) and inhibiting pathogenic bacteria (from 8.54% to 2.36%), thereby facilitating its return toward the original state. These findings suggest that NMMT@PMB is a promising nano-delivery system that may support sustained antibacterial action and microbiota homeostasis, offering a potential strategy for improved management of Salmonella infections.