The Laetiporus sulphureus Fermented Product Enhances the Antioxidant Status, Intestinal Tight Junction, and Morphology of Broiler Chickens

Simple Summary This study investigated the effects of the Laetiporus sulphureus fermented product (FL) as a feed supplement on antioxidant activities, intestinal Tight Junction (TJ) mRNA expression, and the intestinal morphology of broiler chickens. FL supplementation could potentially enhance the feed conversion ratio in broilers by improving their antioxidative status, TJ mRNA expression, and intestinal morphology. Broilers supplemented with 5% FL exhibited the best overall results on improving antioxidant status, TJ mRNA expression, and intestinal morphology. Abstract The Laetiporus sp. is a fungal species that is traditionally used for medicinal purposes. This study investigated the effects of the Laetiporus sulphureus fermented product (FL) as a feed supplementation on the antioxidant activities, the intestinal Tight Junction (TJ) mRNA expression, and the intestinal morphology of broiler chickens. Four-hundred one-day-old male broilers (Ross 308) were randomly allocated to five experimental diets: (1) a corn-soybean meal basal diet (control), (2) a basal diet replaced with 5% Wheat Bran (5% WB), (3) a basal diet replaced with 10% WB (10% WB), (4) a basal diet replaced with 5% FL (5% FL), and (5) a basal diet replaced with 10% FL (10% FL). The FL-supplemented groups exhibited a better feed conversion ratio in the overall experimental period compared to the WB and control groups. The serum antioxidant profiles of 35-day-old broilers showed that, compared to the control and 10% WB groups, the 5% FL supplementation group had a significantly increased superoxide dismutase activity, while it down-regulated the concentration of malondialdehyde in the serum (p < 0.05). The assessment of selected antioxidant gene expression showed that the 5% FL group significantly elevated heme oxygenase-1 and nuclear factor erythroid 2–related factor 2 expression, compared to the control and WB groups (p < 0.05). Furthermore, both of the FL supplemented groups had a significantly higher expression of glutathione peroxidase and catalase, compared to that of the WB and control groups in the jejunum (p < 0.05). The TJ mRNA expression in the jejunum showed that 5% FL significantly elevated the zonula occludens-1, claudin-1, and mucin-2 expression (p < 0.05), while 5% and 10% FL supplementation significantly improved OCLN expression in both the jejunum and ileum, compared to control group (p < 0.05). The intestinal morphology of 35-day-old broilers showed that a 5% FL supplementation significantly increased the villus height in the ileum and jejunum, compared to the WB and control groups (p < 0.05). Moreover, the 5% and 10% FL supplementation groups had a significantly higher villi:crypt ratio in the ileum, compared to the WB and control groups (p < 0.05). To conclude, FL supplementation improved the antioxidative status, the TJ mRNA expression, and the intestinal morphology, and it was accompanied by a lowered feed conversion ratio in broilers. Finally, 5% supplementation had the overall best results in improving the antioxidant status, TJ mRNA expression, and intestinal morphology of broilers.