Effects of supplementation with sweeteners on jejunal mRNA expression of tight junction genes in broiler chickens. Data are presented as mean value ± SEM (n = 6). Values without the same letter (a, b) represent statistically significant differences (P < 0.05). Abbreviations: CON, broiler chickens fed a basal diet; STE, broiler chickens fed a basal diet supplemented with 250 mg/kg stevioside; SUC, broiler chickens fed a basal diet supplemented with 100 mg/kg sucralose; SAC, broiler chickens fed a basal diet supplemented with 600 mg/kg saccharin sodium; CLDN1, claudin 1; CLDN2, claudin 2; ZO-1, zonula occludens-1; OCLN, occludin; MUC2, mucin 2.