The purpose of this study was to see how dietary supplementation with phenylpyruvate affected broiler chicken growth, slaughter performance, gut health microbiota, and immunity. A total of 288 day old broiler chickens were randomly assigned to one of four groups (6 replicates each with 12 chicken). NC (basal diet), PC (basal diet plus antibiotic virginiamycin 15ppm), LCP and HCP (basal diet plus phenylpyruvate 1kg/t and 2kg/t, respectively). Results showed that PC had higher ADFI during the first 21 days, and better FCR than the NC, the LCP and HCP also improved broilers’ FCR 0.001 and 0.037% in relation to NC respectively. HCP has a higher all-eviscerated ratio than NC and less abdominal fat than LCP. HCP has increased villus length and crypt depth in the ileum compared to the NC. Bursa was lower in HCP and thymus was lower in LCP and PC. In contrast HCP have lower pro-inflammatory cytokine IL-1, as well as lower TLR4. The phenylpyruvate improved family Selenomonadaceae, genus Megamonas Bacteroides species that are known for beneficial effects like for maintenance of the cell surface structure, regulating aromatic amino acids and C. jejuni-suppressive treatment respectively. Finally, phenylpyruvate feed supplement can be utilized to improve growth performance and positively modulate gut microbiota, however this is less efficient than antibiotics in improving growth performance, although more efficient in improving productive performance and gut morphology. Moreover, high dose of phenylpyruvate is more effective than low dose