This study aimed to examine the impact of varying concentrations of bile acids (BA) added to the feed on several aspects of Penaeus vannamei. The purity of BA was 25.29%, and its main components were 5.74% chenodeoxycholic acid, 6.27% allocholic acid, 3.20% cholic acid, 5.79% hyodeoxycholic acid, and 2.31% hyocholic acid. The experiment was designed with four groups: CT, BA1, BA2, and BA3, where BA were added to the shrimp basal diet at concentrations of 0.0 mg/kg, 0.1 mg/kg, 1.0 mg/kg, and 10.0 mg/kg, respectively. After 60 days of farming P. vannamei (initial body weight: 1.21 ± 0.05 g), the results showed that BA supplementation significantly improved growth performance, and BA2 group was the most significant, which increased the final weight (FBW) by 18.6%, weight gain rate (WGR) by 19.5%, and survival rate (SR) by 5.8% compared with the CT group (p < 0.05). Additionally, the activities of trypsin and lipase in gut tissue were significantly increased (p < 0.05). Furthermore, BA supplementation increased the activity of antioxidant-related enzymes in the hepatopancreas and enhanced the mRNA expression levels of gut-associated immune genes. In addition, the supplementation of 0.1 mg/kg BA significantly altered the gut microbial composition, reducing the proportion of harmful Proteobacteria while enhancing the relative abundance of beneficial microorganisms such as Firmicutes and Bacteroides. In conclusion, 1.0 mg/kg and 10.0 mg/kg BA supplementation significantly improved the growth performance, digestive capacity, and antioxidant capacity of shrimp, among which 1.0 mg/kg supplementation had the most significant effect and improved the intestinal microbial composition of shrimp.
Keywords: Penaeus vannamei; antioxidant; bile acids; gut microorganisms; immune.