Effect of Next Enhance® 150 and Previda® on growth performance and the intestinal transcriptome of gilthead sea bream (Sparus aurata)

Abstract

In a first trial, gilthead sea bream juveniles were fed different doses (0, 50, 100, 200, 300 ppm) of NE®150 for 9 weeks. Feed gain ratio (FGR) was improved by a 10% with all the doses, but feed intake decreased in a dose dependent manner. The optimum inclusion level to achieve a maximum growth was set at 100 ppm. The hepatosomatic index did not vary and only with the highest dose, the viscerosomatic index and the splenosomatic index were significantly decreased. No significant changes were found in haematological parameters, plasma biochemistry, total antioxidant capacity and respiratory burst. In a second trial, NE150 was given at 100 ppm alone (T1) or in combination with the prebiotic Previda® (0.5%) (T2) for 11 weeks. There were no differences in the growth rates, and FGR was equally improved for T1 and T2. No significant changes in haematology and plasma antioxidant capacity were detected. A 90-gene PCR-array based on our transcriptomic database (www.nutrigroup-iats.org/seabreamdb) was constructed and applied to samples of anterior (AI) and posterior (PI) intestine. It included gene markers of cell differentiation and proliferation, intestinal architecture and permeability, enterocyte mass and epithelial damage, interleukins and cytokines, pathogen recognition receptors (PRR), and mitochondrial function and biogenesis. The intensity of the changes and the number of genes that were significantly regulated were higher in PI than in AI. At PI, both treatments invoked a clear down-regulation of genes involved in cell differentiation and proliferation, some involved in cell to cell communication, interleukin IL-6, and several PRR. By contrast, up-regulation was mostly found for genes related to enterocyte mass, cell epithelial damage and mitochondrial activity at AI. The changes were of the same order for T1 and T2, except for fatty acid-binding proteins 2 and 6 (FABP2, FABP6) and the PRR fucolectin. Thus, the combination of NE150 and Previda induces an anti-inflammatory status and changes in the absorptive capacity of the intestine.