Dietary encapsulated essential oils and organic acids mixture improves gut health in broiler chickens challenged with necrotic enteritis

Background: The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE) due to Clostridium perfringens. In the present study, we investigated the effects of dietary supplementation with a blend of encapsulated essential oils and organic acids(BLJ) on growth performance and gut health using a coinfection model of NE in broiler chickens.Methods: Two hundred and eighty-eight one-day-old male Arbor Acres broiler chicks were randomly assigned using a 2 × 2 factorial design into two groups fed either 0 or 500 mg/kg dietary BLJ and co-challenged(or not challenged for the control) with Eimeria spp./C. perfringens.Results: Infected birds fed the BLJ-supplemented diet exhibited an improved feed conversion ratio throughout the trial(P < 0.01), a higher vil us height and vil us height/crypt depth ratio, and reduced intestinal C. perfringens counts, liver C.perfringens carriage, gut lesion scores and serum fluorescein isothiocyanate dextran(FITC-D) concentrations at 7 d postinfection compared with those of birds without BLJ supplementation(P < 0.05). NE-infected birds fed BLJ exhibited significantly upregulated claudin-1 and IGF-2 m RNA levels(P < 0.05), increased A20 m RNA expression and significantly downregulated TRAF-6, TNFSF15 and TOLLIP m RNA levels in the jejunum at 7 d post-infection compared with those in birds without BLJ supplementation(P < 0.05). Compared with the uninfected and untreated birds, the uninfected birds fed BLJ displayed increased relative abundances of Lactobacil us and Coprococcus but reduced Rikenel aceae levels. Compared with the unsupplemented NE-chal enged birds, infected birds fed BLJ showed an increased relative abundance of Unclassifiedachnospiraceae and a significantly decreased relative abundance of Erysipelotrichaceae.Conclusion: BLJ supplementation improved growth performance and gut health in NE-infected broiler chickens by strengthening the intestinal barrier function, positively modulating the gut microbiota community and differential y regulating intestinal immune responses. Our results also suggested that adding BLJ effectively control ed NE infections after experimental Eimeria and Clostridium perfringens coinfection.