Establish human gut ecosystem simulator for dynamically culturing gut microbiome. Probiotic extracellular vesicles (EV) are used as natural nanocarrier to target pathogen and deliver specific RNAs to treat infection. EV target different tissues after oral administration, effectively inhibiting C. difficile proliferation and virulence without affecting other gut microbiota. The method offers high safety, low cost, high yield, and net-zero emissions, demonstrating significant commercial potential.