Transcript levels of occludin (A), junction adhesion molecules-2 (JAM-2, B) and mucin-2 (Muc-2, C) genes in the duodenal mucosal samples of broiler chickens fed different levels of G-NHG and challenged with C. perfringens on d 21, 22 and 23 of the experiment as measured by RT-qPCR assay. Values are means with their SE in bars. PC (positive control): birds fed a basal diet and challenged with C. perfringens, NC (negative control): birds fed a basal diet, G-NHG (100, 200, 300 or 400 mg/kg)-treated groups: birds fed a basal diet supplemented with 100, 200, 300 or 400 mg/kg of garlic nanohydrogel and challenged with C. perfringens. a–e Means within the same column carrying different superscripts are significantly different at p < 0.05.