A high-grain (HG) diet can result in ruminal subacute acidosis, which is detrimental to gut health and can lead to decreased productivity. This study investigated the ileal epithelial microbiota and its relationship with host epithelial function in goats fed a HG diet (concentrate/hay, 90:10) and a control diet (concentrate/hay, 55:45), aiming to elucidate the mechanisms involved in ileal adaptation to subacute acidosis. The HG challenge increased the ileal volatile fatty acid concentration (p = 0.030) and altered the ileal epithelial microbiota by increasing (FDR < 0.05) relative abundances of active carbohydrate and protein degraders Synergistetes, Prevotella, Fibrobacter, Clostridium, Treponema, and unclassified Ruminococcaceae by 20.1-, 6.3-, 16.8-, 8.5-, 19.9-, and 7.1-fold, respectively. However, the HG diet tended to reduce (FDR < 0.10) the relative abundance of Candidatus Arthromitus (38.8 ± 36.1 versus 2.1 ± 3.1). Microbial functional potentials inferred using PICRUSt indicated that the HG challenge elevated abundances of pathways associated with metabolism of amino acid, glycan, cofactors, and vitamins, whereras it decreased pathways associated with signal transduction, xenobiotic biodegradation, and metabolism. Additionally, in the ileal epithelium of HG goats, transcriptome analysis identified the increment (FDR < 0.10) of candidate genes involved in metabolism of carbohydrates, lipids, proteins, vitamins, and the proinflammatory cytokine pathway, while downregulating genes encoding antimicrobials and complements (FDR < 0.05). Collectively, the HG challenge shifted the structure and functional potentials of the ileal microbial community and affected the host responses in the ileum of goats toward increased metabolic activities of macro- and micronutrients, together with an increased risk of gut inflammation.

中文翻译：

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高粮挑战期间回肠上皮微生物群和宿主转录组之间的联系：对山羊肠道稳态的影响。

高谷物（HG）饮食会导致瘤胃亚急性酸中毒，这对肠道健康有害，并可能导致生产力下降。这项研究调查了饲喂HG日粮（浓缩物/干草，90:10）和对照日粮（浓缩物/干草，55:45）的山羊回肠上皮菌群及其与宿主上皮功能的关系，目的是阐明参与其中的机制回肠适应亚急性酸中毒。所述HG挑战增加回肠挥发性脂肪酸浓度（p = 0.030），并改变了回肠上皮菌群通过增加（FDR <0.05）活性碳水化合物和蛋白质降解菌Synergistetes，的相对丰度普雷沃，Fibrobacter，梭菌属，密螺旋体属和未分类的Ruminococcaceae，分别为20.1、6.3-，16.8-，8.5-，19.9-和7.1倍。然而，HG饮食趋于减少（FDR <0.10）的相对丰度暂定关节炎（38.8±36.1对2.1±3.1）。使用PICRUSt推断出的微生物功能潜力表明，HG挑战提高了与氨基酸，聚糖，辅因子和维生素代谢相关的途径的丰富性，而它降低了与信号转导，异源生物降解和代谢有关的途径。此外，在HG山羊的回肠上皮中，转录组分析确定了参与碳水化合物，脂质，蛋白质，维生素和促炎性细胞因子途径代谢的候选基因的增量（FDR <0.10），同时下调了编码抗菌素和补体（FDR）的基因<0.05）。总的来说，