Zubiri-Gaitán Agostina, Martínez-Álvaro Marina, Blasco Agustín, Hernández Pilar
Institute for Animal Science and Technology, Universitat Politècnica de València, Camino de Vera s/n, Valencia, Spain.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae339.
The gastrointestinal microbiota plays a key role in the host physiology and health through a complex host-microbiota co-metabolism. Metabolites produced by microbial metabolism can travel through the bloodstream to reach distal organs and affect their function, ultimately influencing the development of relevant production traits such as meat quality. Meat quality is a complex trait made up of a number of characteristics and intramuscular fat content (IMF) is considered to be one of the most important parameters. In this study, 52 rabbits from 2 lines divergently selected for IMF (high-IMF (H) and low-IMF (L) lines) were used to perform an untargeted metabolomic analysis of their cecal content, with the aim to obtain information on genetically determined microbial metabolism related to IMF. A large, correlated response to selection was found in their cecal metabolome composition. Partial least squares discriminant analysis was used to identify the pathways differentiating the lines, which showed a classification accuracy of 99%. On the other hand, 2 linear partial least squares analyses were performed, one for each line, to extract evidence on the specific pathways associated with IMF deposition within each line, which showed predictive abilities (estimated using the Q2) of approximately 60%. The most relevant pathways differentiating the lines were those related to amino acids (aromatic, branched-chain, and gamma-glutamyl), secondary bile acids, and purines. The higher content of secondary bile acids in the L-line was related to greater lipid absorption, while the differences found in purines suggested different fermentation activities, which could be related to greater nitrogen utilization and energy efficiency in the L-line. The linear analyses showed that lipid metabolism had a greater relative importance for IMF deposition in the L-line, whereas a more complex microbial metabolism was associated with the H-line. The lysophospholipids and gamma-glutamyl amino acids were associated with IMF in both lines; the nucleotide and secondary bile acid metabolisms were mostly associated in the H-line; and the long-chain and branched-chain fatty acids were mostly associated in the L-line. A metabolic signature consisting of 2 secondary bile acids and 2 protein metabolites was found with 88% classification accuracy, pointing to the interaction between lipid absorption and protein metabolism as a relevant driver of the microbiome activity influencing IMF.
胃肠道微生物群通过复杂的宿主 - 微生物群共代谢在宿主生理和健康中发挥关键作用。微生物代谢产生的代谢物可通过血液循环到达远端器官并影响其功能，最终影响肉品质等相关生产性状的发育。肉品质是一个由多个特征组成的复杂性状，肌内脂肪含量（IMF）被认为是最重要的参数之一。在本研究中，选取了来自2个因IMF而被差异选择的品系（高IMF（H）和低IMF（L）品系）的52只兔子，对其盲肠内容物进行非靶向代谢组学分析，目的是获取与IMF相关的遗传决定的微生物代谢信息。在它们的盲肠代谢组组成中发现了对选择的强烈相关反应。使用偏最小二乘判别分析来识别区分品系的途径，其分类准确率为99%。另一方面，进行了2次线性偏最小二乘分析，每个品系各进行一次，以提取与每个品系内IMF沉积相关的特定途径的证据，其预测能力（使用Q2估计）约为60%。区分品系的最相关途径是与氨基酸（芳香族、支链和γ-谷氨酰）、次级胆汁酸和嘌呤相关的途径。L品系中较高的次级胆汁酸含量与更大的脂质吸收有关，而嘌呤中的差异表明发酵活动不同，这可能与L品系中更高的氮利用和能量效率有关。线性分析表明，脂质代谢对L品系中IMF沉积的相对重要性更大，而更复杂的微生物代谢与H品系相关。溶血磷脂和γ-谷氨酰氨基酸在两个品系中均与IMF相关；核苷酸和次级胆汁酸代谢主要与H品系相关；长链和支链脂肪酸主要与L品系相关。发现了一个由2种次级胆汁酸和2种蛋白质代谢物组成的代谢特征，分类准确率为88%，表明脂质吸收和蛋白质代谢之间的相互作用是影响IMF 的微生物群活动的相关驱动因素。
