Dietary inclusion of Pediococcus acidilactici probiotic promoted the growth indices, hemato-biochemical indices, enzymatic profile, intestinal and liver histomorphology, and resistance of Nile Tilapia against Aspergillus flavus

Abstract

This study investigated the effect of probiotic Pediococcus acidilactici CNCM I-4622 on the water quality, growth indices, hematological parameters, biochemical profile, innate immunity (lysozyme (LYZ) and immunoglobulin M (IgM)), and antioxidant (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX)) and digestive enzymes activity, with reference to the intestinal and liver histology of Nile Tilapia (Oreochromis niloticus), as well as disease resistance against Aspergillus flavus. A field trial was carried out for 56 days in which Nile tilapia fingerlings (4.0 ± 0.3 g) were randomly distributed into three replicate concrete ponds which were subdivided into four treatment groups, receiving P. acidilactici CNCM I-4622 at 0 (T0), 2.0 (T1), 2.5 (T2), and 3.0 (T3) g/kg diet, respectively. The obtained results revealed a significant amelioration in growth, feed utilization, body composition, and blood profiles, including erythrocytes and leukocyte counts, hemoglobin, and hematocrit concentration in the probiotics-treated groups compared to the control group. Dietary P. acidilactici at 2.5 and 3 g/kg diets enhanced the digestive enzymes (amylase, lipase, and protease) relative to the control group (p < 0.05). Biochemical parameters (total protein and albumin levels, and globulin) were notably increased, meanwhile, total cholesterol and triglycerides were significantly decreased in T3 supplemented group with a marked decrease in the levels of AST and ALT. Nevertheless, the serum activity of SOD, CAT, and GPX enzymes as well as LYZ and IgM were increased by P. acidilactici at 2.5 and 3 g/kg relative to the control group (p < 0.05). Also, a markedly increased length of the intestinal villi was prominent in treated fish with P. acidilactici at 2.5 and 3 g/kg. Feeding P. acidilactici at 3 g/kg significantly decreased the cumulative mortalities after the A. flavus challenge. In conclusion, our results presented the beneficial effects of P. acidilactici as a potent probiotic on growth indices, feed utilization, antioxidant properties, gut and liver health, and fungal resistance of Nile tilapia.