GSE193239
Effects of yeast species and processing on transcriptomic profile and intestinal health of Atlantic salmon (Salmo salar) fed soybean meal-based diets in seawater
The objective of the current study was to examine the effects of yeasts on intestinal health and transcriptomic profile of Atlantic salmon fed SBM-based diets in seawater. Cyberlindnera jadinii (CJ) and Wickerhamomyces anomalus (WA) yeasts were produced in-house and processed by direct heat-inactivation with spray-drying (ICJ and IWA) or autolyzed at 50 ºC for 16 h (ACJ and AWA), followed by spray-drying. Six diets were formulated, one based on fishmeal (FM), a challenging diet with 30% soybean meal (SBM) and four other diets containing 30% SBM and 10% of each of the four yeast fractions (i.e., ICJ, ACJ, IWA and AWA). The results showed that the inclusion of CJ yeasts reduced loss of supranuclear vacuolization, along with reduction in population of CD8a positive cells present in the lamina propria of fish fed the SBM diet. The CJ yeasts controlled the inflammatory profile of fish fed SBM through up-regulation of pathways related to wound healing and taurine metabolism. Additionally, the WA yeasts dampened the inflammatory profile of fish fed SBM through down-regulation of pathways related to toll-like receptor signaling, C-lectin receptor, cytokine receptor and signal transduction. The results suggest that yeasts could be used as protein ingredients with functional properties in diets for Atlantic salmon. Overall design: Examination of intestinal health of Atlantic salmon fed diets containing four different yeast treatments.