Table_2_Dietary Amylose/Amylopectin Ratio Modulates Cecal Microbiota and Metabolites in Weaned Goats.xls

Increasing the ratio of amylose in the diet can increase the quantity of starch that flows to the large intestine for microbial fermentation. This leads to the alteration of microbiota and metabolite of the hindgut, where the underlying mechanism is not clearly understood. The present study used a combination of 16S amplicon sequencing technology and metabolomics technique to reveal the effects of increasing ratios of amylose/amylopectin on cecal mucosa- and digesta-associated microbiota and their metabolites in young goats. Twenty-seven Xiangdong black female goats with average body weights (9.00 ± 1.12 kg) were used in this study. The goats were randomly allocated to one of the three diets containing starch with 0% amylose corn (T1), 50% high amylose corn (T2), and 100% high amylose corn (T3) for 35 days. Results showed that cecal valerate concentration was higher (P < 0.05) in the T2 group than those in the T1 and T3 groups. The levels of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were decreased (P < 0.05) in cecal tissue while IL-10 was increased (P < 0.05) in the T2 group when compared with T1 or T3 groups. At the phylum level, the proportion of mucosa-associated Spirochaetes was increased (P < 0.05), while Proteobacteria was deceased by feeding high amylose ratios (P < 0.05). The abundance of Verrucomicrobia was decreased (P < 0.05) in the T3 group compared with the T1 and T2 groups. The abundance of digesta-associated Firmicutes was increased (P < 0.05) while Verrucomicrobia and Tenericutes were deceased (P < 0.05) with the increment of amylose/amylopectin ratios. The LEfSe analysis showed that a diet with 50% high amylose enriched the abundance of beneficial bacteria such as Faecalibacterium and Lactobacillus in the digesta and Akkermansia in the mucosa compared with the T1 diet. The metabolomics results revealed that feeding a diet containing 50% high amylose decreased the concentration of fatty acyls-related metabolites, including dodecanedioic acid, heptadecanoic acid, and stearidonic acid ethyl ester compared with the T1 diet. The results suggested that a diet consisting of 50% high amylose could maintain a better cecal microbiota composition and host immune function.提高日粮中直链淀粉（amylose）占比，可增加流向大肠以供微生物发酵的淀粉总量，进而改变后肠道微生物群与代谢产物组成，但其潜在调控机制尚未明确。本研究结合16S扩增子测序技术与代谢组学技术，探究直链淀粉/支链淀粉（amylopectin）占比升高对青年山羊盲肠黏膜及食糜相关微生物群及其代谢产物的影响。本试验选用27只平均体重为（9.00±1.12）kg的雌性湘东黑山羊，随机分为3组，分别饲喂含0%直链淀粉玉米（T1组）、50%高直链玉米（T2组）及100%高直链玉米（T3组）的日粮，试验周期为35天。结果显示，T2组盲肠戊酸浓度显著高于T1与T3组（P<0.05）。与T1或T3组相比，T2组盲肠组织中肿瘤坏死因子-α（TNF-α）与白细胞介素-6（IL-6）水平显著降低，而IL-10水平显著升高（P<0.05）。在门水平上，饲喂高直链淀粉日粮可显著提升黏膜相关螺旋体门（Spirochaetes）的相对丰度，同时显著降低变形菌门（Proteobacteria）的丰度（P<0.05）；T3组疣微菌门（Verrucomicrobia）的丰度较T1与T2组显著降低（P<0.05）。随着直链淀粉/支链淀粉占比升高，食糜相关厚壁菌门（Firmicutes）丰度显著升高，而疣微菌门与柔膜菌门（Tenericutes）丰度显著降低（P<0.05）。线性判别分析效应大小（Linear Discriminant Analysis Effect Size, LEfSe）分析结果表明，与T1组日粮相比，50%高直链淀粉日粮可提升食糜中有益菌如粪杆菌属（Faecalibacterium）与乳杆菌属（Lactobacillus），以及黏膜中阿克曼氏菌属（Akkermansia）的相对丰度。代谢组学分析结果显示，与T1组相比，饲喂50%高直链淀粉日粮可降低多种脂肪酰类代谢产物的浓度，包括十二烷二酸、十七烷酸及十八碳四烯酸乙酯。本研究结果表明，含50%高直链淀粉的日粮可维持更健康的盲肠微生物群组成与宿主免疫功能。