Figure 6: MMP-1 Activity of Caco-2 cells infected with commensal and pathogenic bacteria and treated with 10% PEG. MMP-1 activity in cells treated with commensal bacterial strains were comparatively lower than when infected with pathogenic (EPEC). PEG significantly reduced the MMP-1 activity when infected with bacteria (both commensal and pathogenic). A 12-fold decrease in MMP-1 activity was noted in samples treated with PEG 8000 and infected with commensal bacteria. 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 (*).