Utilizing dietary probiotics can boost amberjack (Seriola dumerili) lysozyme activity, antioxidant capacity, and gut microbiota

Abstract

In aquaculture, natural and eco-friendly resources are prioritized over synthetic inputs (e.g., antibiotics), and optimizing sustainable production methods is necessary. Probiotics have been well known for various potential functions in animal performance and health when supplemented as a single or mix of strain (s) in the diet. Consuming the right probiotic blend (synergistic types) is more advantageous than using each kind individually due to combining each species' functions. The present trial aimed to examine the potential impacts of two probiotic mixtures on the performance and well-being of amberjack juveniles (5.63 ± 0.04 g; Number = 300) for a 60-day feed trial. Three experimental diets (43.5 ± 0.50% total protein and 12.55 ± 0.17% total lipid) were formulated with no probiotics supplement for the control (CD1) or with probiotics mixture supplement. Probiotic mixtures were supplemented at 2 g/kg diet for groups D2 [Bacillus amyloliquefaciens TOA5001 (BA) + Streptococcus faecalis T-110 (SF)] and D3 [Bacillus amyloliquefaciens, Streptococcus faecalis T-110, Lactobacillus plantarum TO-A, Bacillus mesentericus TO-A] respectively. The analysis revealed no difference in all means of growth parameters, feed utilization, survival rate, biometric indices, whole-body composition, and blood parameters between control and probiotic-supplemented diet groups. Liver lysozyme activity, superoxide dismutase, peroxidase activity, and biological antioxidant (BAP) were significantly improved in fish fed D2 compared to CD1 (P < 0.05). The higher (P < 0.05) content of intestinal lactic acid bacteria was noted in fish group fed diet D2, with an improved intestinal histological structure such as increased villi length, cryptal depth, and goblet cells compared to those provided with CD1 and D3 diets. In conclusion, incorporating a mix of probiotic bacteria [BA+SF] at a 2 g/kg diet has remarkable effects on intestinal health, immune responses, and oxidative status of amberjack, S. dumerili, suggesting a potential probiotic candidate for this species.