Synergistic effect of chlorogenic acid and Saccharomyces boulardii on growth and health performance in Goldfish (Carassius auratus).

The current research investigated the individual and combined effects of chlorogenic acid (CGA) and Saccharomyces boulardii (SB) on growth, health status, and disease resistance in goldfish (Carassius auratus). For this purpose, fish were fed with four experimental diets including control (un-supplemented), CGA (0.5 g/kg diet), SB (1010 CFU/g), and CGA + SB for eight weeks. After eight weeks, the fish were weighed to investigate growth performance and sampled for immune and antioxidant factors evaluation. After feeding trial, the fish were challenged to Aeromonas hydrophila and mortality was recorded for 14 days. The data exhibited that the combined treatment (CGA + SB) significantly improved final weight, weight gain, and specific growth rate, and resulted in the lowest feed conversion ratio (P < 0.05). Meanwhile, immune parameters including lysozyme activity, immunoglobulin levels, and ACH50 were significantly enhanced by CGA, SB and the combination (P < 0.05). In addition, gene expression analysis revealed upregulation of growth-related gene (gh, P < 0.05), antioxidant-related genes (cat, sod, gst, P < 0.05), and pro-inflammatory cytokines (il-8, tnf-α, P < 0.05). Conversely, no marked differences were observed for igf-1, mn-sod, il-6, and tgf-β (P > 0.05). The result showed that the CGA + SB group had the lowest mortality (P < 0.05), compared to the control. In conclusion, dietary supplementation with 0.5 g/kg CGA and 1010 CFU/g SB individual and combined significantly improves goldfish growth, immunity, and disease resistance under the tested condition.