The French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel; Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway.
The French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel.
Fish Shellfish Immunol. 2019 Jun;89:368-377. doi: 10.1016/j.fsi.2019.04.012. Epub 2019 Apr 6.
Recent studies in mammalian models revealed compelling evidence that along with the intrinsic characteristics of diets, the time of their delivery could have a profound impact on their benefits. In this study, we explored a time-dependent modulation of the gut mucosal barrier by delivering diets enriched with the green microalga (Lobosphaera incisa) either in a time-restricted regime or randomly to zebrafish (Danio rerio). The basal diet was enriched with microalgal biomass through two inclusion levels (i.e., 10% and 15% w/w), and the feeding trial lasted for six weeks. The control group was fed with the basal diet. After collection of tissue samples at week 6, the remaining fish were challenged by intraperitoneal injection of Streptococcus inaie. A histological analysis of the gut structure revealed that the fish that received the microalgae randomly exhibited shorter villi length. Genes coding for immunity were modulated in the gut by dietary treatments. Notably, the transcript levels of lysozyme, β-defensin and hepcidin were significantly higher in the group subjected to the time-restricted feeding regime. Dietary microalgae affected the fatty acid content in the gut, particularly the level of arachidonic acid (ARA), and the time-restricted feeding influenced its accumulation. Groups that received diets enriched with 15% microalgae, regardless of the feeding strategy, displayed a significantly higher resistance to S. inaie 16 days post-infection, though differences between the delivery strategies were pronounced during the early stage of infection. In conclusion, the dietary inclusion of L. incisa modulated some of the features of the gut mucosal barrier of zebrafish, and the time of delivery appeared to have a considerable influence on immunomodulatory functions.
最近在哺乳动物模型中的研究提供了令人信服的证据，表明除了饮食的内在特征外，其提供时间也可能对其益处产生深远影响。在这项研究中，我们通过限时或随机向斑马鱼（Danio rerio）投喂富含绿微藻（Lobosphaera incisa）的饮食，探索了饮食时间依赖性对肠道黏膜屏障的调节作用。基础饮食通过两种添加水平（即 10%和 15%w/w）来富集微藻生物量，喂养试验持续六周。对照组用基础饮食喂养。在第 6 周收集组织样本后，用腹腔内注射链球菌（Streptococcus inaie）对剩余的鱼进行攻毒。对肠道结构的组织学分析表明，随机投喂微藻的鱼的绒毛长度较短。肠道中编码免疫的基因受到饮食处理的调节。值得注意的是，在限时喂养组中，溶菌酶、β-防御素和铁调素的转录水平显著升高。饮食微藻影响肠道中的脂肪酸含量，特别是花生四烯酸（ARA）的水平，且限时喂养会影响其积累。无论采用何种喂养策略，摄入 15%微藻的饮食组在感染后 16 天对 S. inaie 的抵抗力显著提高，但两种投喂策略之间的差异在感染早期较为明显。总之，L. incisa 的饮食添加物调节了斑马鱼肠道黏膜屏障的某些特征，而投喂时间似乎对免疫调节功能有相当大的影响。
