Unit Nutritional Physiology, Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria.
Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, 1210 Vienna, Austria.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad165.
In the immediate time after weaning, piglets often show symptoms of gut inflammation. The change to a plant-based diet, lack of sow milk, and the resulting novel gut microbiome and metabolite profile in digesta may be causative factors for the observed inflammation. We used the intestinal loop perfusion assay (ILPA) to investigate jejunal and colonic expression of genes for antimicrobial secretion, oxidative stress, barrier function, and inflammatory signaling in suckling and weaned piglets when exposed to "plant-oriented" microbiome (POM) representing postweaning digesta with gut-site specific microbial and metabolite composition. Two serial ILPA were performed in two replicate batches, with 16 piglets preweaning (days 24 to 27) and 16 piglets postweaning (days 38 to 41). Two jejunal and colonic loops were perfused with Krebs-Henseleit buffer (control) or with the respective POM for 2 h. Afterward, RNA was isolated from the loop tissue to determine the relative gene expression. Age-related effects in jejunum included higher expression of genes for antimicrobial secretions and barrier function as well as reduced expression of pattern-recognition receptors post- compared to preweaning (P < 0.05). Age-related effects in the colon comprised downregulation of the expression of pattern-recognition receptors post- compared to preweaning (P < 0.05). Likewise, age reduced the colonic expression of genes encoding for cytokines, antimicrobial secretions, antioxidant enzymes, and tight-junction proteins post- compared to preweaning. Effect of POM in the jejunum comprised an increased the expression of toll-like receptors compared to the control (P < 0.05), demonstrating a specific response to microbial antigens. Similarly, POM administration upregulated the jejunal expression of antioxidant enzymes (P < 0.05). The POM perfusion strongly upregulated the colonic expression of cytokines and altered the expression of barrier function genes, fatty acid receptors and transporters, and antimicrobial secretions (P < 0.05). In conclusion, results indicated that POM signaled via altering the expression of pattern-recognition receptors in the jejunum, which in turn activated the secretory defense and decreased mucosal permeability. In the colon, POM may have acted pro-inflammatory via upregulated cytokine expression. Results are valuable for the formulation of transition feeds for the immediate time after weaning to maintain mucosal immune tolerance towards the novel digesta composition.
在断奶后的即时阶段，仔猪通常会出现肠道炎症的症状。改为植物性饮食、缺乏母猪奶以及由此导致的消化物中新的肠道微生物组和代谢物特征可能是观察到的炎症的原因。我们使用肠道环灌流测定法（ILPA）来研究在暴露于“以植物为导向”的微生物组（POM）时，哺乳期和断奶期仔猪的回肠和结肠中与抗菌分泌、氧化应激、屏障功能和炎症信号有关的基因表达，POM 代表了具有肠道特定微生物和代谢物组成的断奶后消化物。在两个重复批次中进行了两次连续的 ILPA，有 16 头仔猪在预断奶（第 24 至 27 天）和 16 头仔猪在断奶后（第 38 至 41 天）。用 Krebs-Henseleit 缓冲液（对照）或相应的 POM 灌流 2 小时后，从环组织中分离 RNA，以确定相对基因表达。回肠中的年龄相关影响包括与预断奶相比，抗菌分泌和屏障功能的基因表达增加，模式识别受体的表达减少（P<0.05）。与预断奶相比，结肠中的年龄相关影响包括模式识别受体的表达下调（P<0.05）。同样，年龄降低了与预断奶相比的结肠中编码细胞因子、抗菌分泌物、抗氧化酶和紧密连接蛋白的基因的表达。POM 在回肠中的作用包括与对照相比， toll 样受体的表达增加（P<0.05），这表明对微生物抗原的特异性反应。同样，POM 给药上调了回肠中抗氧化酶的表达（P<0.05）。POM 灌流强烈地上调了结肠中细胞因子的表达，并改变了屏障功能基因、脂肪酸受体和转运体以及抗菌分泌物的表达（P<0.05）。总之，结果表明，POM 通过改变回肠中模式识别受体的表达来发出信号，这反过来又激活了分泌防御并降低了黏膜通透性。在结肠中，POM 可能通过上调细胞因子表达而发挥促炎作用。这些结果对于制定断奶后立即使用的过渡饲料很有价值，以维持对新消化物组成的黏膜免疫耐受。
