Our previous study has shown that supplementation of trace amounts of antibiotic exacerbated the detrimental effects of enterotoxigenic E. coli (ETEC) infection and delayed the recovery of pigs that may be associated with modified metabolites and metabolic pathways. Therefore, the objective of this study was to explore the impacts of trace levels of antibiotic (carbadox) on host metabolic profiles and colon microbiota of weaned pigs experimentally infected with ETEC F18. The multivariate analysis highlighted a distinct metabolomic profile of serum and colon digesta between trace amounts of antibiotic (TRA; 0.5 mg/kg carbadox) and label-recommended dose antibiotic (REC; 50 mg/kg carbadox) on d 5 post-inoculation (PI). The relative abundance of metabolomic markers of amino acids, carbohydrates, and purine metabolism were significantly differentiated between the TRA and REC groups (q < 0.2). In addition, pigs in REC group had the highest (P < 0.05) relative abundance of Lactobacillaceae and tended to have increased (P < 0.10) relative abundance of Lachnospiraceae in the colon digesta on d 5 PI. On d 11 PI, pigs in REC had greater (P < 0.05) relative abundance of Clostridiaceae compared with other groups, whereas had reduced (P < 0.05) relative abundance of Prevotellaceae than pigs in control group. Trace amounts of antibiotic resulted in differential metabolites and metabolic pathways that may be associated with its slow responses against ETEC F18 infection. The altered gut microbiota profiles by label-recommended dose antibiotic may contribute to the promotion of disease resistance in weaned pigs.

中文翻译：

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微量抗生素改变了感染致病性大肠杆菌的断奶猪的代谢组学和微生物特征

我们之前的研究表明，补充微量抗生素会加剧产肠毒素大肠杆菌 (ETEC) 感染的有害影响，并延迟猪的恢复，这可能与代谢物和代谢途径的改变有关。因此，本研究的目的是探讨微量抗生素 (carbadox) 对实验性感染 ETEC F18 的断奶猪的宿主代谢特征和结肠微生物群的影响。多变量分析强调了在接种后第 5 天（PI ）。氨基酸、碳水化合物、代谢组学标志物的相对丰度 TRA 组和 REC 组之间的嘌呤代谢有显着差异（q < 0.2）。此外，REC 组猪的乳酸杆菌科相对丰度最高（P < 0.05），并且在 5 天 PI 时结肠食糜中毛螺菌科的相对丰度趋于增加（P < 0.10）。在第 11 天 PI，与其他组相比，REC 猪的梭菌科相对丰度更高（P < 0.05），而普氏菌科的相对丰度低于对照组（P < 0.05）。微量抗生素导致不同的代谢物和代谢途径，这可能与其对 ETEC F18 感染的缓慢反应有关。标签推荐剂量抗生素改变的肠道微生物群谱可能有助于促进断奶猪的抗病性。