Sus scrofa scrofa Transcriptome or Gene expression

Abrupt weaning imposes highly variable physiological stress on pigs, yet the mechanisms underlying this variability remain poorly understood. We applied an integrative approach combining transcriptomics, gastrointestinal phenotyping, and blood biomarkers to characterize gut-brain axis dynamics at one week post-weaning (day 7) and at the end of the nursery phase (day 39) in pigs with divergent early performance. Twenty-four pigs of similar weaning weight (5.65 kg) were selected from pens showing extreme early feed intake post-weaning and subsequently classified by average daily gain (ADG) as a proxy for individual feed intake (n = 12 per time point). RNA sequencing of ileal and hypothalamic tissue revealed that low-ADG pigs at day 7 exhibited impaired intestinal barrier function, suppressed metabolic and immune pathways, and hypothalamic activation of appetite-suppressing (mTORC1, GLP-1) and thermogenic signaling, together with endocrine disruption. By day 39, digestive and metabolic pathways were upregulated in the ileum of low-ADG pigs, yet gut integrity deficits persisted alongside sustained hypothalamic immune activation and disrupted appetite signaling. Blood profiles indicated prolonged metabolic imbalance, characterized by elevated triglycerides, insulin, leptin, and TNF-alpha, and reduced PYY. Collectively, these findings define a "low feed intake syndrome", in which early nutrient deprivation, compromised gut integrity, and dysregulated neuroendocrine signaling converge to perpetuate poor growth and long-term maladaptation.

仔猪早期断奶会使其承受高度异质性的生理应激，但目前学界对该应激异质性背后的分子机制仍知之甚少。本研究采用整合转录组学（transcriptomics）、胃肠道表型分析（gastrointestinal phenotyping）与血液生物标志物（blood biomarkers）的研究策略，针对早期生长性能存在显著差异的仔猪，在断奶后1周（第7天）及保育阶段末期（第39天）两个时间点解析其肠-脑轴（gut-brain axis）的动态变化。本研究从断奶后早期采食量呈现极端分化的栏舍中，选取24头断奶重相近（5.65 kg）的仔猪，随后以平均日增重（average daily gain, ADG）作为个体采食量的替代指标进行分组，每个时间点各纳入12头仔猪。对回肠与下丘脑组织进行RNA测序（RNA sequencing）的结果显示，第7天时低ADG仔猪存在肠道屏障功能受损、代谢与免疫通路受抑制的现象，同时下丘脑的食欲抑制通路（mTORC1、GLP-1）与产热信号通路被激活，并伴随内分泌紊乱。至第39天时，低ADG仔猪回肠中的消化与代谢通路已呈现上调，但肠道完整性缺陷仍持续存在，同时伴随下丘脑免疫激活与食欲信号通路紊乱。血液检测结果显示仔猪存在长期代谢失衡，特征为甘油三酯、胰岛素、瘦素及肿瘤坏死因子α（TNF-α）水平升高，而肽YY（PYY）水平降低。综上，本研究结果定义了一种"低采食量综合征"：早期营养剥夺、肠道完整性受损与神经内分泌信号通路失调共同作用，持续引发仔猪生长不良及长期适应不良。