Transcriptome Analysis Reveals Effect of Dietary Probiotics on Immune Response Mechanism in Southern Catfish () in Response to .

To explore whether a probiotic complex composed of , , and can prevent or inhibit the inflammatory response caused by the invasion of in the southern catfish, we screened differentially expressed genes and enriched inflammation-related pathways among a control and three experimental groups and conducted analysis by transcriptome sequencing after a 21-day breeding experiment. Compared with those in the PS () group, southern catfish in the L-PS () group had no obvious haemorrhages or ulcerations. The results also showed that inflammation-related genes, such as , , , , , , , and , were significantly upregulated in the PS group compared with those in the L-PS groups. In addition, we verified six DEGs (, , , , , and ) and three proteins (CXCR4, NFKBIA, and CALR) by qRT-PCR and ELISA, respectively. Our results were consistent with the transcriptome data. Moreover, significantly downregulated genes ( < 0.05) were enriched in inflammation-related GO terms (lymphocyte chemotaxis and positive regulation of inflammatory response) and immune-related pathways (intestinal immune network for IgA production and IL-17 signalling pathway) in the L-PS vs. the PS group. Our results indicate that the infection of can produce an inflammatory response, and probiotics could inhibit the inflammatory response caused by to some extent.