植物乳杆菌制剂对断奶仔猪肠道黏膜功能和微生物菌群及短链脂肪酸的影响

[目的]本试验旨在研究植物乳杆菌制剂对苏淮断奶仔猪肠道黏膜营养素转运体、紧密连接蛋白相关基因表达量、微生物菌群数量、短链脂肪酸及乳酸含量的影响。[方法]选取胎次和体质量（9.34 kg）相近的28日龄健康苏淮断奶仔猪144头，按饲喂日粮随机分为对照组（基础日粮）、抗生素组（基础日粮+抗生素）、植物乳杆菌制剂组（基础日粮+植物乳杆菌制剂），每组6个重复，每个重复8头仔猪。预饲期3 d，仔猪32日龄开始试验，59日龄试验结束时屠宰采样。采集十二指肠、空肠、回肠组织及黏膜样品分别用于黏膜营养素转运体和紧密连接蛋白相关基因表达量分析；分别收集盲肠和结肠食糜，测定短链脂肪酸和乳酸含量，RT-qPCR分析微生物菌群数量。[结果]与对照组相比，植物乳杆菌制剂组可显著上调十二指肠PepT1、空肠SGLT-1和PepT1以及回肠SGLT-1基因的相对表达量（P<0.05），与抗生素组相比，植物乳杆菌对各基因的相对表达量均无显著影响（P>0.05）；与对照组和抗生素组相比，植物乳杆菌制剂组可显著上调十二指肠Occludin、空肠和回肠Occludin和ZO-1基因的相对表达量（P<0.05），而对十二指肠、空肠、回肠其他基因无明显影响（P>0.05）；与对照组相比，植物乳杆菌制剂组可显著增加盲肠丁酸、结肠丁酸和乳酸的含量（P<0.05），而对乙酸和丙酸无显著影响（P>0.05）；显著减少大肠杆菌数量（P<0.05），显著增加结肠乳酸杆菌和梭菌ⅩⅣa群的数量（P<0.05）；相较于抗生素组，植物乳杆菌制剂可显著提高盲肠乳酸、结肠乳酸和丁酸含量以及盲肠和结肠中乳酸杆菌的数量（P<0.05）。[结论]仔猪断奶时饲喂植物乳杆菌制剂可调节肠道黏膜营养素转运体及紧密连接蛋白相关基因表达量，提高短链脂肪酸和乳酸含量，促进肠道有益菌如乳酸杆菌、梭菌ⅩⅣa群的增殖，减少病原菌如大肠杆菌数量，从而促进肠道健康，缓解断奶应激。
[Objectives] The experiment aims to investigate the effects of Lactobacillus plantarum on genes expression of nutrient transporters, tight junction protein in small intestine mucosa, microbial populations, short chain fatty acids and lactic acid of Suhuai weaned piglets. [Methods] A total of 144 Suhuai weaned piglets(9.34 kg)at age of 28 days were randomly divided into 3 groups, including control group(basal diet), antibiotics group(basal diet supplemented with antibiotics)and L.plantarum group(basal diet supplemented with L.plantarum). Each group had 6 replicates and 8 piglets per replicate. The experiment started on day 32 and ended on day 59 after birth. On day 59, one piglet from each replicate was slaughtered for sampling. On the day of slaughter, the tissue and mucosa samples of duodenum, jejunum and ileum, and digesta samples of cecum and colon were collected, respectively. [Results] Compared with the control group, L.plantarum treatment increased mRNA expression of PepT1 in duodenum(P<0.05), SGLT-1, PepT1 in jejunum and SGLT-1 in ileum(P<0.05). Further, L.plantarum increased mRNA relative expression of Occludin in duodenum, and Occludin, ZO-1 in jejunum and ileum in comparison with the control and antibiotics group(P<0.05). Results also showed that L.plantarum presented a higher concentration of buyrate in cecum, buyrate and lactic acid in colon than that in the control group(P<0.05), while no significant effect was observed on the concentration of acetate and propionate. In terms of bacteria population, L.plantarum decreased the population of Escherichia coli in cecum and colon, increased the population of Lactobacillus and Clostridium cluster ⅩⅣa in colon(P<0.05). In contrast with the antibiotics