MCP-1 secretion of Caco-2 cells after treatment with EcN. Caco-2 cells were cocultured with E. coli MG1655 (+ K12) and EcN (+ EcN) for 6 hours. Culture supernatants were analyzed for several cytokines using the cytometric bead array kit I from BD Bioscience. Cytokine quantity is depicted as pg/ml. Data are presented as mean from two independent experiments.