IL6 and infection: Dietary supplementation with phages significantly reduced IL-6, IFN- γ, IL-1 β, and IL-10 mRNA expression on day 3 post-infection (p < 0.05) compared to group M. In this study, we found that Salmonella infection caused increased expression of pro-inflammatory factors IL-6, IFN- γ, and IL-1 β in chickens, whereas either pre – or simultaneous supplementation of phage reversed this phenomenon.