■基于植物的营养计划是将鱼在生命早期阶段短时间暴露于基于植物的饮食的概念,以改善在后期暴露于类似的富含植物的饮食时的生理反应阶段。营养程序背后的作用机制尚未完全破译,并且可以在多个级别控制响应。
■这项为期22周的研究检查了营养编程后的肠道转录变化。一式三份的大西洋鲑鱼用植物(V)与一个海洋丰富的(M,对照)饮食2周(刺激阶段)在第一次外源喂养。然后将两个刺激鱼组(M和V鱼)喂食M饮食12周(中间阶段),最后喂食V饮食(挑战阶段)6周,跨阶段产生两种饮食方案(MMV和VMV)。这项研究使用全转录组方法来分析V饮食在刺激结束时(短期影响)和首次喂养后22周(长期影响)的影响。在刺激之后,由于其发展阶段,使用了整个肠道,然而,挑战之后,检查幽门盲肠和中肠和远端肠。
■在刺激结束时,在V鱼中表达增加的基因富集途径,包括调节表观遗传反应和脂质代谢,和参与先天免疫反应的基因下调。在挑战结束时的中肠,脂质基因的表达水平,碳水化合物,V形鱼的能量代谢增加,而M鱼显示与自身免疫和急性适应性免疫反应相关的基因表达增加。V鱼的远端肠显示与免疫应答和潜在免疫耐受相关的基因表达增加。相反,在挑战中,M鱼的远端肠道揭示了脂质和碳水化合物代谢途径的上调,组织变性,和凋亡反应。本研究证明了肠道转录组的营养编程相关变化,涉及免疫反应和不同代谢过程的基因表达改变。虽然群体之间的增长变化有限,结果表明存在转录差异,建议编程响应,尽管这种反应的机制仍需要完全阐明。
UNASSIGNED: Plant-based nutritional programming is the concept of exposing fish at very early life stages to a plant-based diet for a short duration to improve physiological responses when exposed to a similar plant-rich diet at a later developmental stage. The mechanisms of action underlying nutritional programming have not been fully deciphered, and the responses may be controlled at multiple levels.
UNASSIGNED: This 22-week study examines gut transcriptional changes after nutritional programming. Triplicate groups of Atlantic salmon were fed with a plant (V) vs. a marine-rich (M, control) diet for 2 weeks (stimulus phase) at the first exogenous feeding. Both stimulus fish groups (M and V fish) were then fed the M diet for 12 weeks (intermediate phase) and lastly fed the V diet (challenge phase) for 6 weeks, generating two dietary regimes (MMV and VMV) across phases. This study used a whole-transcriptome approach to analyse the effects of the V diet at the end of stimulus (short-term effects) and 22 weeks post-first feeding (long-term effects). After the stimulus, due to its developmental stage, the whole intestine was used, whereas, after the challenge, pyloric caeca and middle and
distal intestines were examined.
UNASSIGNED: At the stimulus end, genes with increased expression in V fish enriched pathways including regulatory epigenetic responses and lipid metabolism, and genes involved in innate immune response were downregulated. In the middle intestine at the end of the challenge, expression levels of genes of lipid, carbohydrate, and energy metabolism were increased in V fish, while M fish revealed increased expression of genes associated with autoimmune and acute adaptive immune response. The
distal intestine of V fish showed increased expression of genes associated with immune response and potential immune tolerance. Conversely, the
distal intestine of M fish at challenge revealed upregulation of lipid and carbohydrate metabolic pathways, tissue degeneration, and apoptotic responses. The present study demonstrated nutritional programming-associated changes in the intestinal transcriptome, with altered expression of genes involved in both immune responses and different metabolic processes. While there were limited changes in growth between the groups, the results show that there were transcriptional differences, suggesting a programming response, although the mechanism of this response still requires to be fully elucidated.