Efficacy of dietary fermented vegetable product on immune response, up-regulation of immune-related genes and protection of kuruma shrimp (Marsupenaeus japonicus) against Vibrio parahaemolyticus

The present study was carried out to investigate the effects of dietary fermented vegetable product (FVP) on the innate immune response, immune-related genes expression and resistance of kuruma shrimp Marsupenaeus japonicus against Vibrio parahaemolyticus. Four hundred and eighty healthy kuruma shrimp (15.3 ± 1.15 g) were distributed into four treatment groups and fed with diets containing 0 (control), 0.55, 5.5, and 55 g FVP (kg diet)−1 for 11 days. The results revealed that administration of FVP significantly elevated the innate immune parameters of kuruma shrimp including total hemocyte count (THC), phagocytosis, phenoloxidase activity, reactive oxygen species (ROS) production and bactericidal activity (P < 0.05). Furthermore, dietary supplementation of 5.5, and 55 g FVP (kg diet)−1 remarkably up-regulated the expression of antimicrobial peptides (AMPs) and toll-like receptors (TLR) in various tissues, particularly in the intestine. Shrimp groups supplemented with FVP diets showed significantly lower cumulative mortality percentage after being challenged with Vibrio parahaemolyticus (P < 0.05). The results suggest that FVP can be recommended as a feed supplement to elevate innate immune response, upregulate immune related genes expression and increase disease resistance in kuruma shrimp.