Excessive large intestinal PA results in lasting impairment of the intestinal barrier in IL10-/-mice. (A) Experimental setup: Untreated IL10-/- mice (ctr), V/M-treated IL10-/- mice at Day 2 of the treatment (V/M), and V/M-treated IL10-/- mice 7 days after discontinuation of the V/M treatment (post-V/M) were investigated. (B, C) Fecal and cecal serine protease activity. (D) Plasma concentration of fluorescein isothiocyanate dextran (4 kDa) 4 hours after oral gavage. (E) Ussing chamber analyses of cecal and colonic tissue. (F) mRNA expression level of IL1β and CD3 in colonic tissue. (G) Experimental schedule: V/M-treated IL10-/- mice were orally gavaged with the serine protease inhibitor AEBSF (V/M-AEBSF) or H2O (V/M-wat), starting from 1 day before V/M treatment. (H, I) Fecal and cecal serine protease activity. (J) Plasma concentration of fluorescein isothiocyanate dextran (4 kDa) 4 hours after oral gavage. (K) Ussing chamber analyses of fluorescein translocation and TEER in colonic tissue sections. FITC, fluorescein isothiocyanate.