The probiotic Bacillus subtilis strain 29784 (Bs29784) has been shown to improve performance in broilers. In this study, we used a metabolomic and 16S rRNA gene sequencing approach to evaluate effects of Bs29874 in the broiler intestine. Nicotinic acid and hypoxanthine were key metabolites that were produced by the strain in vitro and were also found in vivo to be increased in small intestinal content of broilers fed Bs29784 as dietary additive. Both metabolites have well-described anti-inflammatory effects in the intestine. Furthermore, Bs29784 supplementation to the feed significantly altered the ileal microbiome of 13-day-old broilers, thereby increasing the abundance of genus Bacillus, while decreasing genera and OTUs belonging to the Lactobacillaceae and Enterobacteriacae families. Moreover, Bs29784 did not change the cecal microbial community structure, but specifically enriched members of the family Clostridiales VadinBB60, as well as the butyrate-producing families Ruminococcaceae and Lachnospiraceae. The abundance of various OTUs and genera belonging to these families was significantly associated with nicotinic acid levels in the cecum, suggesting a possible cross-feeding between B. subtilis strain 29784 and these beneficial microbes. Taken together, the data indicate that Bs29784 exerts its described probiotic effects through a combined action of its metabolites on both the host and its microbiome.

中文翻译：

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枯草芽孢杆菌 29784 作为肉鸡饲料添加剂可改变肠道微生物组成并支持次黄嘌呤和烟酸的产生

益生菌枯草芽孢杆菌菌株 29784 (Bs29784) 已被证明可以提高肉鸡的生产性能。在本研究中，我们使用代谢组学和 16S rRNA 基因测序方法来评估 Bs29874 在肉鸡肠道中的作用。烟酸和次黄嘌呤是该菌株在体外产生的关键代谢物，并且在体内也发现以 Bs29784 作为膳食添加剂饲喂肉鸡的小肠含量有所增加。两种代谢物在肠道中都具有良好的抗炎作用。此外，在饲料中添加 Bs29784 显着改变了 13 日龄肉鸡的回肠微生物组，从而增加了芽孢杆菌属的丰度，同时减少了属于乳杆菌科和肠杆菌科的属和 OTU。此外，Bs29784并没有改变盲肠微生物群落结构，而是特别富集了梭菌目VadinBB60家族的成员，以及产丁酸的瘤胃球菌科和毛螺旋菌科的成员。属于这些科的各种 OTU 和属的丰度与盲肠中的烟酸水平显着相关，表明枯草芽孢杆菌菌株 29784 和这些有益微生物之间可能存在交叉喂养。总而言之，数据表明 Bs29784 通过其代谢物对宿主及其微生物组的联合作用来发挥其所描述的益生菌作用。