E. coli MG1655-mediated ANP aggravation involved TLR4 and ERS signaling. (A and B) Comparison of TLR4 (A) and ERS (B) signaling molecules after ANP induction between gut microbiota-depleted rats and conventional rats. *, P < 0.05 versus the SO group; #, P < 0.05 versus the ABX group; +, P < 0.05 versus the ANP group. (C and D) Comparison of TLR4 (C) and ERS (D) signaling molecules after ANP induction between E. coli MG1655-monocolonized rats and gut microbiota-depleted rats. n = 10 per group. Three independent experiments were performed. Data were analyzed using one-way ANOVA, followed by Bonferroni’s posttest. *, P < 0.05 versus the ABX group; #, P < 0.05 versus the ABX+MG1655 group; +, P < 0.05 versus the ABX+ANP group. SO, sham operated.