Browsing by Author "Perez-Sanchez, Jaume"
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- Dietary butyrate helps to restore the Intestinal status of a marine teleost (Sparus aurata) fed extreme diets low in fish meal and fish oilPublication . Estensoro, Itziar; Ballester-Lozano, Gabriel; Benedito-Palos, Laura; Grammes, Fabian; Martos-Sitcha, Juan Antonio; Mydland, Liv-Torunn; Calduch-Giner, Josep Alvar; Fuentes, Juan; Karalazos, Vasileios; Ortiz, Alvaro; Overland, Margareth; Sitja-Bobadilla, Ariadna; Perez-Sanchez, JaumeThere is a constant need to find feed additives that improve health and nutrition of farmed fish and lessen the intestinal inflammation induced by plant-based ingredients. The objective of this study was to evaluate the effects of adding an organic acid salt to alleviate some of the detrimental effects of extreme plant-ingredient substitution of fish meal (FM) and fish oil (FO) in gilthead sea bream diet. Three experiments were conducted. In a first trial (T1), the best dose (0.4%) of sodium butyrate (BP-70 (R) NOREL) was chosen after a short (9 weeks) feeding period. In a second longer trial (T2) (8 months), four diets were used: a control diet containing 25% FM (T2-D1) and three experimental diets containing 5% FM (T2-D2, T2-D3, T2-D4). FO was the only added oil in D1, while a blend of plant oils replaced 58% and 84% of FO in T2-D2, and T2-D3 and T2-D4, respectively. The latter was supplemented with 0.4% BP-70. In a third trial (T3), two groups of fish were fed for 12 and 38 months with D1, D3 and D4 diets of T2. The effects of dietary changes were studied using histochemical, immunohistochemical, molecular and electrophysiological tools. The extreme diet (T2-D3) modified significantly the transcriptomic profile, especially at the anterior intestine, up-regulating the expression of inflammatory markers, in coincidence with a higher presence of granulocytes and lymphocytes in the submucosa, and changing genes involved in antioxidant defences, epithelial permeability and mucus production. Trans-epithelial electrical resistance (Rt) was also decreased (T3-D3). Most of these modifications were returned to control values with the addition of BP-70. None of the experimental diets modified the staining pattern of PCNA, FABP2 or ALPI. These results further confirm the potential of this additive to improve or reverse the detrimental effects of extreme fish diet formulations.
- Dietary tryptophan supplementation induces a transient immune enhancement of gilthead seabream (Sparus aurata) juveniles fed fishmeal-free dietsPublication . Ramos-Pinto, Lourenco; Martos-Sitcha, Juan A.; Reis, Bruno; Azeredo, Rita; Fernandez-Boo, Sergio; Perez-Sanchez, Jaume; Alvar Calduch-Giner, Josep; Engrola, Sofia; Conceicao, Luis E. C.; Dias, Jorge; Silva, Tome S.; Costas, BenjaminEuropean aquaculture is an industry with a high sustainability profile contributing to the supply of safe seafood. However, several diseases can affect farmed fish and it is imperative to find alternatives for chemotherapeutic treatments when disease outbreaks occur. Maintenance of health through nutrition is well-establish in modern animal farming, and amino acids (AA) are promising candidates as functional additives to improve fish health. Therefore, the goal of this research is to provide a better understanding of the influence of tryptophan supplementation on nutritional condition and immune mechanisms in fish. Triplicate groups of fish (13.3 +/- 0.3g) previously fed with a fishmeal-based diet were either fed a control diet with an extreme formulation (0% fishmeal) but meeting the AA requirements (CTRL), or the SUP diet, formulated as the CTRL with an increase in tryptophan (TRP) content. After 2 and 13 weeks of feeding, head-kidney (HK), liver (L) and white skeletal muscle (WSM) were collected for gene expression, whereas plasma was suited for humoral immune parameters. A holistic approach using transcriptomic, humoral and zootechnical parameters was undertaken. The expression of 29-31 genes for WSM, L or HK confirms an effect due to the treatment across time. A two-way ANOVA analysis revealed that 15-24 genes varied significantly depending on the tissue, and the multivariate analysis by means of PLS-DA explained (R-2) and predicted (Q(2)) with four components up to 93% and 78% of total variance, respectively. Component 1 (R-2 = 50.06%) represented the time effects, whereas components 2 (24.36%) and 3 (13.89%) grouped fish on the basis of dietary treatment, at early sampling. The HK results in particular suggest that fish fed SUP diet displayed an immunostimulated state at 2 weeks. No major differences were observed in plasma humoral parameters, despite an increase in antiprotease and peroxidase activities after 13 weeks regardless of dietary treatment. These results suggest that tryptophan supplementation may improve the seabream immune status after 2 weeks. Hence, the use of functional feeds is especially relevant during a short-term feeding period before a predictable stressful event or disease outbreak, considering that these putative advantageous effects seem to disappear after a 13 weeks feeding period.
- European Sea Bass (Dicentrarchus labrax) immune status and disease resistance are impaired by arginine dietary supplementationPublication . Azeredo, Rita; Perez-Sanchez, Jaume; Sitja-Bobadilla, Ariadna; Fouz, Belen; Tort, Lluis; Aragao, Claudia; Oliva-Teles, Aires; Costas, BenjaminInfectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the immune response. Aiming at finding out how arginine affects the innate immune status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A third diet meeting arginine requirement level for seabass served as control diet. Following 15 or 29 days of feeding, fish were sampled for blood, spleen and gut to assess cell-mediated immune parameters and immune-related gene expression. At the same time, fish from each dietary group were challenged against Vibrio anguillarum and survival was monitored. Cell-mediated immune parameters such as the extracellular superoxide and nitric oxide decreased in fish fed arginine-supplemented diets. Interleukins and immune-cell marker transcripts were down-regulated by the highest supplementation level. Disease resistance data were in accordance with a generally depressed immune status, with increased susceptibility to vibriosis in fish fed arginine supplemented diets. Altogether, these results suggest a general inhibitory effect of arginine on the immune defences and disease resistance of European seabass. Still, further research will certainly clarify arginine immunomodulation pathways thereby allowing the validation of its potential as a prophylactic strategy.