Inclusion of Pediococcus acidilactici as probiotic candidate in diets for beluga (Huso huso) modifies biochemical parameters and improves immune functions.

Administration of probiotic candidates in fish has generally been shown as a useful strategy to improve growth performance, survival, digestive enzyme activity, and gut microbiota. Unfortunately, the sero-immunological responses of different fish to different probiotic candidates are poorly understood. The present study assessed the effect of Pediococcus acidilactici as a probiotic on the biochemical and immunological parameters of beluga. Fish (248.32 ± 10.21 g) were fed a control diet (without P. acidilactici( and three different doses of P. acidilactici-supplemented diets (10, 10, and 10 CFUg diets) for 8 weeks. On week 8, blood and serum were sampled. Dose-dependent increase of immunological parameters (respiratory burst activity, lysozyme content, serum antibacterial activity, and total immunoglobulin) and biochemical parameters (total protein and albumin levels) was observed. However, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in the juvenile beluga fed by 10 CFUg P. acidilactici-supplemented diet compared to the other groups. Based on the results of this evaluation, it is reasonable to conclude that the inclusion of P. acidilactici as probiotic in diets for juvenile beluga improves the sero-immunological parameters of the fish and should be considered by farmers as a strategy to improve fish health.