Zou X Y, Zhang M, Tu W J, Zhang Q, Jin M L, Fang R D, Jiang S
Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, PR China.
Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, PR China; Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, PR China.
Animal. 2022 Mar;16(3):100474. doi: 10.1016/j.animal.2022.100474. Epub 2022 Feb 24.
Bacillus subtilis is one of the most popular commercial probiotics used in farm animal production. However, its potential mechanisms are not very clear. The aim of this study was to investigate the effects of dietary Bacillus subtilis on intestinal histomorphology, innate immunity, microbiota composition, transcriptomics, and related metabolomics. Twenty-four 48-week-old Lohman Pink-shell laying hens were randomly divided into two groups: a basic diet and the basic diet supplemented with Bacillus subtilis (0.5 g/kg) for a 9-week experiment. At the end of the experiment, tissues of the duodenum, ileum, and jejunum as well as cecal content of each bird were collected for microstructure, PCR, transcriptome, metabolome, and 16S rRNA analyses. The results showed that dietary Bacillus subtilis supplement had no effect on the intestinal microstructure. However, Bacillus subtilis increased mRNA expression of tight junction protein occludin (P < 0.05), while reduced mRNA expression of lipopolysaccharide-induced TNF factor (P < 0.01) in the duodenum. Moreover, transcriptomic results indicated that most of Bacillus subtilis supplement-induced differential genes were associated with inflammation and immunity, including cytochrome b-245 beta chain, transferrin, and purinergic receptor P2X 7, resulting in a decrease in Malondialdehyde level (P < 0.05) in the duodenum. In addition, at the genus level, Bacillus subtilis supplement enriched the potential beneficial bacteria, Candidatus_Soleaferrea (P = 0.02) but inhibited the harmful bacteria including Lachnospiraceae_FCS020_group, Ruminiclostridium, Lachnospiraceae_UCG-010, and Oxalobacter. Metabolomic results revealed that N-Acetylneuraminic acid and ADP were increased by fed Bacillus subtilis. These results suggest that dietary Bacillus subtilis could inhibit gut inflammation and improve antioxidative status and barrier integrity of the duodenum via regulating gut microbial composition in laying hens.
枯草芽孢杆菌是家畜生产中最常用的商业益生菌之一。然而，其潜在机制尚不完全清楚。本研究旨在探讨日粮中添加枯草芽孢杆菌对蛋鸡肠道组织形态、先天免疫、微生物群组成、转录组学及相关代谢组学的影响。将24只48周龄的罗曼粉壳蛋鸡随机分为两组：一组饲喂基础日粮，另一组在基础日粮中添加枯草芽孢杆菌（0.5 g/kg），进行为期9周的试验。试验结束时，采集每只鸡的十二指肠、回肠和空肠组织以及盲肠内容物，进行微观结构、PCR、转录组、代谢组和16S rRNA分析。结果表明，日粮中添加枯草芽孢杆菌对肠道微观结构没有影响。然而，枯草芽孢杆菌增加了十二指肠中紧密连接蛋白闭合蛋白的mRNA表达（P < 0.05），同时降低了脂多糖诱导的TNF因子的mRNA表达（P < 0.01）。此外，转录组学结果表明，大多数枯草芽孢杆菌添加诱导的差异基因与炎症和免疫相关，包括细胞色素b-245β链、转铁蛋白和嘌呤能受体P2X7，导致十二指肠中丙二醛水平降低（P < 0.05）。此外，在属水平上，添加枯草芽孢杆菌富集了潜在的有益菌——暂定索氏菌属（P = 0.02），但抑制了包括毛螺菌科FCS020组、瘤胃梭菌属、毛螺菌科UCG-010和草酸杆菌属在内的有害菌。代谢组学结果显示，饲喂枯草芽孢杆菌可增加N-乙酰神经氨酸和ADP的含量。这些结果表明，日粮中添加枯草芽孢杆菌可通过调节蛋鸡肠道微生物组成来抑制肠道炎症，改善十二指肠的抗氧化状态和屏障完整性。
