Fig. 3

Oral supplementation with Trp, or dL.P. increases aryl hydrocarbon receptor and antibacterial protein and NF-κB DNA binding activity of the intestinal mucosa under antibiotic treatment. a Antibiotic treatment significantly decreased aryl hydrocarbon receptor and antibacterial protein expression of the intestinal mucosa including RELMβ and CRP-ductin as compared with the control mice. Oral feeding of tryptophan or dead L. plantarum feeding increased Ahr, RELMβ, and CRP-ductin expression in the intestinal mucosa in WT mice as compared with the antibiotic treatment group. The Ahr, RELMβ, and CRP-ductin were identified by western immunoblots. Data are presented as mean ± SEM. b Antibiotic treatment significantly decreased the NF-κB DNA binding activity of the intestinal mucosa as compared to that of the control group. Oral feeding of tryptophan or dead L. plantarum feeding significantly increased the NF-κB DNA binding activity of the intestinal mucosa as compared with the antibiotic group. Data are presented as mean ± SEM; *P < 0.05, **P < 0.01