Nitrite nitrogen stress disrupts the intestine bacterial community by altering host-community interactions in shrimp

Environmental stress can disrupt the intricate interactions between the host and intestine microbiota, thereby impacting the host health. In this study, we aimed to elucidate the dynamic changes in the bacterial community within shrimp intestines under nitrite nitrogen (nitrite-N) stress and investigate potential host-related factors influencing these changes. Our results revealed a significant reduction in community diversity within the intestine exposed to nitrite-N compared to control conditions. Furthermore, distinct differences in community structures were observed between these two groups at 72 h and 120 h post-stress induction. Nitrite-N stress also altered the abundances of some bacterial species in the intestine dramatically. It is noteworthy that, in comparison to the 72 h, intestine bacterial community structure of stressed shrimp exhibited a significantly higher degree of dispersion after 120 h of nitrite-N stress when compared to control shrimp, and the relative abundance of numerous bacterial species experienced a substantial decrease or even reached 0 %. Moreover, it led to a reduction in bacterial community interactions and decreased competitiveness within the intestine microbiota. Notably, the influence of bacterial community assemblies in the shrimp intestine shifted from a stochastic process to a deterministic one after 24 h and 72 h of nitrite-N stress, returning to a stochastic process at 120 h. We further observed a close association between this phenomenon and host's response to nitrite-N stress. Expression levels of differentially expressed genes in the intestinal tissue significantly impact the intestine bacterial diversity and abundance of species. In particular, the significant decline in bacterial diversity and abundances of quite a few species in intestine was attributed to the up-regulation of peritrophin-48-like. Overall, nitrite-N stress indeed disrupted the intestine microbiota and changed the host-microbiota interactions of shrimp. This study offered novel insights into environment-host-microbiota interactions and also provided practical guidance for promoting healthy shrimp cultivation practices.