BackgroundReducingSalmonellainfection in broiler chickens by using effective and safe alternatives to antibiotics is vital to provide safer poultry meat and minimize the emergence of drug-resistantSalmonellaand the spread of salmonellosis to humans. This study was to first evaluate the protective efficacy of feeding coated essential oils and organic acids mixture (EOA) on broiler chickens infected withSalmonellaEnteritidis (S. Enteritidis, SE), and then its action mechanism was further explored.MethodsA total of 480 1-day-old Arbor Acres male chickens were randomly assigned into five treatments with six replicates, including non-challenged control fed with basal diet (A), SE-challenged control (B), and SE-infected birds fed a basal diet with 300 mg/kg of EOA (BL), 500 mg/kg of EOA (BM) and 800 mg/kg of EOA (BH), respectively. All birds on challenged groups were infected withSalmonellaEnteritidis on d 13.ResultsFeeding EOA showed a reversed ability on negative effects caused by SE infection, as evidenced by decreasing the feed conversion rate (FCR) and the ratio of villus height to crypt depth (VH/CD) (P< 0.05), obviously decreasing intestinal and internal organsSalmonellaload along with increasing cecal butyric acid-producing bacteria abundance (P< 0.05). Moreover, supplemental different levels of EOA notably up-regulated claudin-1 (CLDN-1), occludin (OCLN), zonula occludens-1 (ZO-1), mucin-2 (MUC-2), fatty acid binding protein-2 (FABP-2), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), myeloid differential protein-88 (MyD88) and interleukin-6 (IL-6) mRNA levels in the ileum of the infected chickens after challenge, whereas down-regulated toll-like receptor-4 (TLR-4) mRNA levels (P< 0.05). Linear discriminant analysis combined effect size measurements analysis (LEfSe) showed that the relative abundance ofg_Butyricicoccus,g_Anaerotruncusandg_unclassified_f_Bacillaceaesignificantly was enriched in infected birds given EOA. Also, phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis showed that alpha-linolenic acid metabolism, fatty acid metabolism and biosynthesis of unsaturated fatty acids were significantly enriched in the EOA group.ConclusionOur data suggest that the essential oils and organic acids mixture can be used as an effective strategy to ameliorate and alleviateSalmonellaEnteritidis infection in broilers.