Powder of the White Bottom Mushroom, Agaricus bisporus (Agaricomycetes), Improved Immunomodulatory and Health-Promoting Effects of Lactobacillus casei in Zebrafish (Danio rerio).

This study was conducted to investigate the effects of Lactobacillus casei and Agaricus bisporus administration, alone or in combination, on skin mucus immune parameters and the expression of selected genes related to growth, appetite, mucosal immunity, and antioxidant enzymes in zebrafish (Danio rerio). Zebrafish (n = 600) were randomly stocked in 12 aquariums and assigned to 1 of 4 treatments, which were repeated in triplicate. During a 60-day feeding trial, fish were fed experimental diets: (1) basal diet (control group); (2) basal diet + L. casei (107 colony-forming units/g; Pro group); (3) basal diet + 1% A. bisporus [mushroom powder [MP] group); and (4) basal diet + 1% A. bisporus + L. casei (107 colony-forming units/g) (MP + Pro group). The results demonstrated that oral administration of A. bisporus + L. casei significantly (P < 0.05) upregulated the expression of growth-related genes (gh and igf1). Similar results were observed for expression of mucosal immune-related genes (tnf-alpha, lyz, and il1b) and for antioxidant-related genes (sod, cat) in zebrafish fed A. bisporus + L. casei (P < 0.05). Also, nonspecific skin mucus immune parameters in the MP + Pro group were significantly (P < 0.05) higher than those in the MP, Pro, and control groups. These results also demonstrate the potential of combined administration of A. bisporus and L. casei as a beneficial feed additive in aquaculture.