Fig. 4. Reparative effect of ECN-pE(C/A)2 on the colonic epithelium and in vivo safety evaluation.

a, b Representative immunofluorescence staining images of colon sections to indicate the expression of tight junction proteins, including ZO-1 (a) and Occludin (b), 10 days after different treatments from two biologically independent animals. d, e Relative fluorescence intensity of colon sections as shown in (a) and (b). The nuclei were stained with DAPI (blue). Scale bar: 50 μm. c Representative TUNEL staining images of the colon tissues of mice in different groups from two biologically independent animals. f Relative fluorescence intensity of colon sections as shown in (c). The nuclei were stained with DAPI (blue). Scale bar: 50 μm. The mice were given PBS or ECN-pE(C/A)₂ (1 × 10⁸ CFU) on days 0, 2, 4, and 6 by gavage. g Complete blood and serum biochemistry data were obtained on day 10 after ECN-pE(C/A)₂ treatment. ALT alanine aminotransferase, AST aspartate aminotransferase, ALB albumin, BUN blood urea nitrogen. Data are presented as mean values ± SEM (n = 6 biologically independent samples for (d–f), n = 5 biologically independent samples for (g)). Statistical analysis was evaluated with two-tailed Student’s t tests (*P  < 0.05, **P  < 0.01, ***P  <  0.001, and ****P  <  0.0001). ZO-1 zonula occludens-1, DAPI 4’,6-diamidino-2-phenylindole, DSS dextran sodium sulfate. Source data are provided as a Source Data file.