Figure 7: MMP-13 activity for Caco-2 cells infected with commensal and pathogenic bacteria and treated with 10% PEG. There was no change in MMP-13 activity in samples treated with either PEG 3350 or PEG 8000 as compared to control regardless of infection status. Infection with commensal bacteria or EPEC slightly decreased the MMP-13 activity. This was not statistically significant. Standard Student’s t-test was applied to the samples and the were obtained for samples treated with PEG 8000 and HS4 indicated by an asterisk (*).