Commercial probiotics enhance growth and immunity of white shrimp (Litopenaeus vannamei) and resistence to infection by Vibrio parahaemolyticus

Abstract

This study evaluated the benefits of a commercial probiotic, Aqua Fortuna probiotic (AFPB), containing multiple bacterial strains isolated from fish gut microbiota, on the physiological performance of white-leg shrimp (Litopenaeus vannamei). Juvenile shrimp were fed varying doses of AFPB (0.5%, 1%, 2%, and 5%) during their maturation period, and their growth indices, including weight, growth rate, feed conversion ratio, and survival rate, were measured biweekly. In addition, gene expression levels of growth factors (IGF1, IGFBP, VEGF1–3) and immune-related markers (antimicrobial peptides: penaeidin-3a, crustin, lysozyme; pattern recognition receptors: β-1,3-glucan binding protein, lipopolysaccharide, and β-glucan binding protein; detoxification enzymes: SOD, prophenoloxidase, hemocyanin) were analyzed in digestive tissues via qPCR on week 8. Furthermore, L. vannamei was challenged with Vibrio parahaemolyticus, and post-challenge survival rates were monitored. The results revealed that AFPB supplementation significantly enhanced the growth performance of L. vannamei. Notably, 1% of AFPB yielded the most significant improvements in the final weights, specific growth rates, and better survival rates. During the lethal challenge with V. parahaemolyticus, groups treated with 5% and 2% AFPB showed higher survival rates at 4 and 8 weeks, respectively. Gene expression analyses showed that 1% AFPB upregulated penaeidin-3a, crustin, lysozyme, prophenoloxidase, superoxide dismutase, and β-1, 3 glucans binding protein in digestive tissues, whereas 2% AFPB additionally upregulated immune genes like prophenoloxidase and lysozyme. Our findings highlight the role of shrimp microbiota in promoting growth and enhancing disease resistance, providing robust evidence for the use of probiotics as a strategy to improve shrimp cultivation productivity.