PDF(Pubmed)
Abstract：
Paraprobiotics (dead/inactivated probiotics) are promising candidates in functional feeds to promote growth performance, modulate intestinal microbiota and enhance immune response of fish. During industrial production, fish are exposed to several stressful conditions such as handling, sub-optimal nutrition and diseases that can lead to reduced growth, increased mortalities and large economical losses. Such problems can be mitigated by use of functional feeds, leading to more-sustainable aquaculture and improved animal welfare. Lactiplantibacillus plantarum strain L-137 is a common bacterium found in fermented Southeast Asian dish made from fish and rice. The benefits of its heat-killed form (HK L-137) related to growth performance and immunomodulation have been studied in farmed fish such as Nile Tilapia (Oreochromis niloticus), striped catfish (Pangasianodon hypophthalmus) and bighead catfish (Clarias macrocephalus). To study if such benefits can also be observed in salmonids, we worked both at in vitro level using an intestinal epithelium cell line from rainbow trout (Oncorhynchus mykiss; RTgutGC) stimulated with HK L-137 (Feed LP20™) and at in vivo level with pre-smolt Atlantic salmon (Salmo salar) fed HK L-137 at different inclusion levels (20, 100 and 500 mg of Feed LP20™ kg-1 feed). In RTgutGC, the results showed that the barrier function of the cell monolayer was strengthened along with an increased production of IL-1β and a decreased production of Anxa1, indicating a modulation of the immune response. Interestingly, a similar trend was detected at the in vivo level in distal intestine from fish fed the highest inclusion level of HK L-137. Here, a lower production of Anxa1 was also detected (after a 61-day feeding period) in addition to an increase of total plasma IgM in the same group. Furthermore, the RNA-seq analysis showed that HK L-137 was able to modulate the gene expression of pathways related to molecular function, biological process and cellular component in distal intestine, without compromising fish performance and gut microbiota. Taken together, our study has shown that HK L-137 can modulate physiological response of Atlantic salmon, making fish more robust against stressful conditions during production.
摘要：
副益生菌（死/灭活益生菌）是有希望的候选功能饲料，以促进生长性能，调节肠道菌群并增强鱼类的免疫反应。在工业生产过程中,鱼暴露在几种压力条件下，如处理，可能导致生长减少的次优营养和疾病，死亡率增加和巨大的经济损失。这些问题可以通过使用功能馈送来缓解，导致更可持续的水产养殖和改善动物福利。植物乳杆菌菌株L-137是在由鱼和大米制成的发酵东南亚菜肴中发现的常见细菌。已在尼罗·罗非鱼（Oreochromisniloticus）等养殖鱼类中研究了其与生长性能和免疫调节相关的热杀死形式（HKL-137）的益处，条纹cat鱼（Pangasianodonhypothmus）和bighead鱼（Clariasmacrocephalus）。为了研究这种好处是否也可以在鲑鱼中观察到，我们在体外水平上使用来自虹鳟鱼（Oncornchusmykiss；RTgutGC）的肠上皮细胞系以HKL-137（FeedLP20™）刺激，并在体内水平上使用不同包含水平（20、100和500mg的FeedLP20™kg-1饲料）饲喂前大西洋鲑鱼（Salmosalar）。在RTgutGC中，结果表明，随着IL-1β的产生增加和Anxa1的产生减少，细胞单层的屏障功能得到增强，表明免疫反应的调节。有趣的是,在饲喂最高包含水平HKL-137的鱼的体内远端肠中检测到类似的趋势。这里,在同一组中,除了总血浆IgM增加外,Anxa1的产量也降低(在61天的饲喂期后).此外，RNA-seq分析表明，HKL-137能够调节与分子功能相关的通路的基因表达，远端肠道的生物过程和细胞成分，在不损害鱼类性能和肠道微生物群的情况下。一起来看,我们的研究表明，HKL-137可以调节大西洋鲑鱼的生理反应，使鱼在生产过程中对压力条件更加健壮。
