Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Chinese Academy of Sciences, Changsha, Hunan, China.
University of Chinese Academy of Sciences, Beijing 100039, China.
Oxid Med Cell Longev. 2022 Mar 30;2022:3355687. doi: 10.1155/2022/3355687. eCollection 2022.
Since the human and porcine digestive systems have similar anatomical structures and physiological functions, pigs are a useful animal model for studying human digestive diseases. By investigating intestinal metabolites in piglets after weaning, this study attempted to identify the inherent connection between dietary protein levels and changes in the intestinal microbiota of piglets. Casein was employed as the only source of protein for the piglets in this study to avoid the influence of other protein sources. 14 weaning at 28-day-old piglets (6.9 ± 0.19 kg) formed into two dietary groups: 17% casein fed group (LP) and 30% casein fed group (HP). Piglets were allowed to free food and water during the 2-week experiment. Throughout the trial, the piglets' diarrhea index (1: no diarrhea and 3: watery diarrhea) and food intake were noted during the experiment. We discovered piglets fed a high-protein diet developed diarrhea throughout the duration of the research, whereas piglets fed a normal protein diet did not. In addition, the HP group had lower feed intake and body weight than the control group ( < 0.05). The HP diet influenced the content of short-chain and branched-chain fatty acids in the colon, including acetate and isovaleric acid. The ileal microbiota's 16S rRNA gene was sequenced, and it was discovered that the relative abundance of gastrointestinal bacteria differed between the HP and control groups. Dietary protein levels influenced bile acid biosynthesis, alpha-linolenic acid metabolism, phospholipid biosynthesis, arachidonic acid metabolism, fatty acid biosynthesis, retinol metabolism, arginine and proline metabolism, pyrimidine metabolism, tryptophan metabolism, and glycine and serine metabolism, according to gas chromatography-mass spectrometry analysis. Furthermore, a correlation analysis of the pooled information revealed a possible link between intestinal metabolites and specific bacteria species. These findings demonstrate that weaned piglets' microbiota composition and metabolites are modified by a high-protein diet and thus inducing severe postweaning diarrhea and inhibiting growth performance. However, the potential molecular mechanism of this regulation in the growth of piglets remains unclear.
由于人和猪的消化系统具有相似的解剖结构和生理功能，因此猪是研究人类消化疾病的有用动物模型。本研究通过研究断奶后仔猪的肠道代谢物，试图确定饮食蛋白水平与仔猪肠道微生物群变化之间的内在联系。本研究中仅使用酪蛋白作为仔猪的蛋白质来源，以避免其他蛋白质源的影响。选择 28 日龄（6.9±0.19kg）的 14 头仔猪分为 2 个日粮组：17%酪蛋白组（LP）和 30%酪蛋白组（HP）。在 2 周的试验期间，仔猪自由采食和饮水。在整个试验过程中，记录仔猪的腹泻指数（1：无腹泻；3：水样腹泻）和采食量。我们发现，饲喂高蛋白日粮的仔猪在整个研究过程中均出现腹泻，而饲喂正常蛋白日粮的仔猪则没有。此外，HP 组的采食量和体重均低于对照组（ < 0.05）。HP 日粮影响了结肠中短链和支链脂肪酸的含量，包括乙酸和异戊酸。对回肠微生物 16S rRNA 基因进行测序，发现 HP 组和对照组的胃肠道细菌相对丰度存在差异。气相色谱-质谱分析结果表明，饮食蛋白水平影响胆汁酸生物合成、α-亚麻酸代谢、磷脂生物合成、花生四烯酸代谢、脂肪酸生物合成、视黄醇代谢、精氨酸和脯氨酸代谢、嘧啶代谢、色氨酸代谢、甘氨酸和丝氨酸代谢。此外，对汇总信息的相关性分析表明，肠道代谢物与特定细菌种类之间可能存在联系。这些发现表明，高蛋白日粮会改变断奶仔猪的微生物组成和代谢物，从而诱导严重的断奶后腹泻和抑制生长性能。然而，这种调节对仔猪生长的潜在分子机制尚不清楚。
