Effect of dietary Pediococcus pentosaceus MR001 on intestinal bacterial diversity and white spot syndrome virus protection in Pacific white shrimp

This study investigated the effect of Pediococcus pentosaceus MR001 on white spot disease (WSD) resistance and the intestinal microbiota of Litopenaeus vannamei. In a two-way white spot syndrome virus (WSSV) infection, probiotic supplementation significantly increased the survival of L. vannamei (p < 0.05) when compared to the control group. This result coincided with the upregulation of immunity (hemocyanin, prophenoloxidase, su-peroxide dismutase, LvToll, and STAT) and the reduced WSSV copy number in shrimp given P. pentosaceus MR001 treatment. The probiotic feeding group also significantly enhanced the expression of intestinal digestion (amylase, trypsin, chymotrypsin, fatty acid binding protein, and fatty acid synthase)-related genes. Moreover, 16S rRNA gene analysis was performed using Illumina sequencing technology to investigate the bacterial composition in the intestine of shrimp during probiotic administration. The results showed that P. pentosaceus MR001 could considerably increase the abundance of potential probiotics and reduce the abundance of potential pathogenic bacteria in the shrimp intestine. Additionally, the metagenomic prediction showed that gut micro -biota in shrimp with and without probiotic feedings are related to the diverse pathways. In the probiotic feeding group, the microbiota was mostly related to metabolism, especially the degradation pathway. Our findings suggest that MR001 can improve immune responses and alter the gut microbiota, which may help in preventing WSD in L. vannamei.