Combination of bacteriophage–probiotics alleviates intestinal barrier dysfunction by regulating gut microbiome in a chick model of multidrug-resistant Salmonella infection

Abstract Background The rapid emergence of multidrug-resistant Salmonella in poultry demands alternative control strategies beyond conventional antibiotics. In this study, we evaluated a combination of lytic Salmonella-infecting bacteriophages (SLAM_phiST45 and SLAM_phiST56) and a probiotic bacterium Limosilactobacillus reuteri (SLAM_LAR11) in a chick model challenged with Salmonella enterica serovar Typhimurium infection. Results Co-administration with two-phage cocktail and a probiotic showed markedly reduced Salmonella colonization in the gut and systemic organs of chicks, comparable to the effect of phage-only treatment. In contrast with phage-only treatment, the combined therapy significantly improved the rate of body-weight change from the day of infection to necropsy (P