This study evaluated the dietary addition of Biotronic® Top3 (BT; a blend of organic acids, cinnamaldehyde, and a permeabilizing complex), on growth performance, digestive enzymes activity, intestine pH, and transcriptomic responses of growth, appetite, and intestinal tight junction proteins genes in common carp fingerlings. The feeding trial was designed with four dietary levels of BT including BT-0 (control group; basal diet free from BT), BT-0.5 (basal diet +0.5 g/kg BT), BT-1 (basal diet+1 g/kg BT), and BT-2 (basal diet+2 g/kg BT) in three replicates. The fingerlings (N = 600; 28.26 ± 0.56 g) were randomly allocated to 12 tanks (containing 250 L water) and fed with the experimental diets for 8 weeks. After the feeding trial, the growth indices such as weight gain and specific growth rate in BT-2 treatment were significantly higher than others (P < 0.05). Meanwhile, the feed conversion ratio showed a remarkable decrease in BT-2 treatment (P < 0.05). The protease and amylase activities were significantly increased in BT-added groups compared to the control group and the highest values were obtained in BT-2 treatment (P < 0.05). Lipase activity was not statistically different in the treated fish with 1 and 2 g/kg BT, but it was significantly higher than the control group (P < 0.05). The group fed with BT-2 diet showed a significant decreasing trend in the pH of the initial-gut compared to the control group (P < 0.05). The transcription levels of growth hormone, insulin-like growth factor-1, and ghrelin genes were significantly up-regulated in BT-2 treatment compared to the control group (P < 0.05). The expression of claudin-3, claudin-7, and occludin genes in BT-2 was significantly higher than others (P < 0.05). Taken together, the oral administration of BT at 2 g/kg can act as a growth promoter by improving the digestive functions in common carp.