TNF and Sepsis: In order to investigate the molecular mechanisms of the effect of EcN on the intestinal barrier function, Caco-2 monolayers were further utilized as the model of intestinal epithelia in vitro, and 10 ng/mL TNF-α and 10 ng/mL IFN-γ were added into the basolateral chambers of transwell plates to induce injuries of the monolayer's barrier function, mimicking the scenario in sepsis.