The effect of Neoagaro-oligosaccharides as an immunostimulant against WSSV infection in shrimp

Oligosaccharides, a prominent class of natural bioactive ingredients, have garnered significant interest in aquaculture due to their diverse biological functions, including immune enhancement and pathogen defense. Among these, Neoagaro-oligosaccharides (NAOs), derived from algae polysaccharides, have emerged as promising bioactive compounds due to their antioxidant and immunomodulatory properties. However, their potential application in antiviral defense in shrimp aquaculture remains unclear. In the present study, the antiviral potential of NAOs against white spot syndrome virus (WSSV) was evaluated in the kuruma shrimp, Marsupenaeus japonicus . Through a combination of transcriptomic and 16S rRNA gene sequencing, our results demonstrated that NAOs administration significantly attenuated WSSV infection and improved shrimp survival rates. Specifically, NAOs mitigated WSSV-induced metabolic reprogramming, such as glycolysis, while simultaneously augmenting the expression of immunity-related genes and the activities of immunity-related enzymes. Furthermore, NAOs improved the intestinal microbiota to bolster shrimp resistance against WSSV infection. These findings highlight the potential of NAOs as novel, non-toxic functional additives for controlling viral outbreaks in shrimp aquaculture and provide new insights into the multi-dimensional mechanisms of oligosaccharide-mediated viral resistance.