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- Nordvi, M. F., et al.
(författare)
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Fucoidan from Undaria pinnatifida mitigates intestinal inflammation in Atlantic salmon (Salmo salar)
- 2023
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Ingår i: Aquaculture. - 0044-8486. ; 575
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Tidskriftsartikel (refereegranskat)abstract
- Using functional feed ingredients to increase the intestinal health of Atlantic salmon (Salmo salar) could allow greater variation and higher inclusion of plant-based proteins in the feed. This is beneficial both for the fish feed industry and fish welfare. Components with strong bioactive properties, such as fucoidans from marine macroalgae, have a great potential as a functional feed ingredient. In the present trial, we challenged Atlantic salmon (Salmo salar) post-smolts with 17.8% soya HP48, a diet that has been shown to cause low-level intestinal inflammation. Fucoidan from Undaria pinnatifida was included at 0, 1, or 3% (Control, FUC1, and FUC3, respectively) to study its ability to alleviate this low-level inflammation . The fish were fed the diets in triplicate tanks for 59 days. At the end of the experiment, the fish were euthanised and the mid-and hind intestine were sampled for morphological-, integrity-(Ussing chamber) and gene expressional-(RNAseq) assessments. Addition of 3% fucoidan lowered the protein digestibility of the feed, however, this did not result in significant differences in the growth parameters. The paracellular permeability of the hydrophilic marker 14C-mannitol tended to decrease with the addition of fucoidan in both tissue segments. The active transport of L-lysine in the mid intestine was significantly reduced in a dose-dependent manner of fucoidan. An anti-inflammatory effect of fucoidan was observed in the hind intestine with significant reductions in the stratum granulosum width and lamina propria height of fish fed FUC1 and FUC3 compared to the Control. This suggests that U. pinnatifida fucoidan can have positive effect on both intestinal integrity and immune regulation of Atlantic salmon (Salmo salar).
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| 2. |
- Nordvi, M. F., et al.
(författare)
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Low intestinal inflammation model (HP48) in Atlantic salmon (Salmo salar) and inflammatory mitigation by Bactocell
- 2023
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 563
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Tidskriftsartikel (refereegranskat)abstract
- Moderate levels of intestinal damage and inflammation are often seen in intensive fish aquaculture. The causes may be due to antinutrients from plant meals, stress or other causes. There is currently a lack of good models to explore these effects and so how to mitigate the consequences. Most studies have used full-fat soy or other compounds that cause intestinal damage that are likely not reversible. In this study we have explored the pos-sibility of using soybean HP48, made from solvent extracted peeled soybeans, as a low-inflammation model in post-smolt Atlantic salmon, and then investigated whether supplementation of the probiotic Pediococcus acid-ilactici CNCM I-4622 - MA 18/5 M (Bactocell) could diminish this effect. The fish were fed triplicate diets. A Control diet containing 18.08% soy protein concentrate (SPC), a HP48 diet where most of the SPC was replaced by HP48 (5.00% SPC and 17.68% HP48), and a Bactocell diet that was identical to the HP48 diet but contained 0.03% Bactocell. After 10 weeks of feeding, the mid-and hind-intestinal health were assessed by histology, integrity (Ussing chamber) and gene expression (RNAseq). Transcriptomic and integrity data suggests that HP48 led to a disturbed mid-intestinal homeostasis with impaired cellular integrity and increased inflammation and cell turnover. Most of the transcriptomic effects were reversed with Bactocell including downregulation of im-mune genes and upregulation of transmembrane proteins such as type IV collagen, which is important in restoring epithelial homeostasis. In the hind-intestine, the HP48 diet led to deleterious morphological changes such as widening of lamina propria and stratum granulosum, disrupted mucosal folds, loss of absorptive vacu-oles, and upregulation of several immune regulated genes and downregulation of genes involved in solute-and water transport. The intestinal integrity assessed by Ussing chamber was not affected. Bactocell supplementation did alleviate several of the morphological effects. However, it was not able to completely reverse the expression of immune-or transport related genes, suggesting a higher effect of probiotic supplement in the mid-intestine compared to the hind-intestine. This study demonstrates that the level of HP48 used here is sufficient to create low-level intestinal changes in Atlantic salmon, which is within range for functional feed ingredients to reverse.
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