A total of 350 broiler chicks (Ross) were used to examine the effects of pro-, prebiotic and symbiotic use on the immune response. The chicks were assigned into 14 groups and different mixtures of probiotics, prebiotics and symbiotics were added to the drinking water / feed. The 1st group (T1) was fed diet with no additives, the second (T2) was fed probiotic mixture at a count of 108 CFU/ml and the rest of groups were fed prebiotics (blend of Mannan and Beta Glucan) at different concentrations (50, 150, 250, 350, 450 and 550 ppm) with probiotic mixture T3, T5, T7, T9, T11 and T13 and without probiotic mixture (T4, T6, T8, T10, T12 and T14), respectively. During the experiment (42 days), body weights, body weight gain and feed intake were calculated weekly and feed conversion ratio was calculated at the end of the experiment. At the end of the experiment, representative number from each group was slaughtered and its intestines were collected for estimation of the expression of IL4, IL6, TLR2 and TLR4 genes. The findings revealed that providing probiotics in drinking water and prebiotics at a concentration of 150 ppm in feed enhanced the immune response of broilers and improved their feed conversion ratio (FCR). This suggests that probiotics and prebiotics may serve as reliable, safe, and natural alternatives to antibiotic growth promoters. Although probiotics did not significantly impact performance parameters, they exhibited a positive effect as an immune stimulant, as demonstrated by the increased mRNA levels of immune-related genes.