Liu Yuchen, Li Lianhong, Yan Huaxiang, Ning Zhonghua, Wang Zhong
National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Microorganisms. 2022 Jul 20;10(7):1469. doi: 10.3390/microorganisms10071469.
The production performance and disease resistance of laying hens decrease obviously with age. This study aimed to investigate the effects of supplementary Lactobacillus salivarius (L. salivarius) SNK-6 on laying performance, the immune-related gene expression in cecal tonsil, and the cecal microbial composition of laying hens. Here, 384 Xinyang black commercial hens (55 weeks old) were randomly allocated to three groups under the same husbandry and dietary regimes: basal diet (Con), the low L. salivarius SNK-6 group (T1: 1.0 × 106 CFU/g), and the high L. salivarius SNK-6 group (T2: 1.0 × 107 CFU/g). The results showed that the feed intake and broken-egg rate in the T1 group were significantly higher than the Con group (p < 0.05). Meanwhile, expressions of intestinal mucosal immune-related genes were significantly upregulated. The 16S rRNA gene sequencing indicated that supplementary L. salivarius SNK-6 had no significant difference in α -diversity and only displayed a trend difference in the β-diversity of cecal microbiota (p = 0.07). LEfSe and random forest were further used to identify bacteria family Enterobacteriaceae, order RF39, genera Ochrobactrum, and Eubacterium as biomarkers between the Con and T1 groups. Genera Ochrobactrum, which had high relative abundance and nodal degree in the T1 and T2 groups, showed a significant positive correlation with the expression of TLR-6, IL-10, MHC-II, and CD40 in cecal tonsils and might play a critical role in activating the host intestinal mucosal immune responses. Overall, dietary supplementary L. salivarius SNK-6 can display an immunomodulatory function, possibly by regulating cecal microbial composition. However, the changes in immune responses may be at the expenditure of corresponding production performance, which needs to be weighed up in practical application.
蛋鸡的生产性能和抗病能力会随着年龄的增长而显著下降。本研究旨在探讨补充唾液乳杆菌（L. salivarius）SNK-6对蛋鸡产蛋性能、盲肠扁桃体免疫相关基因表达以及盲肠微生物组成的影响。在此，384只55周龄的信阳黑商品蛋鸡在相同的饲养和日粮条件下被随机分为三组：基础日粮组（Con）、低剂量唾液乳杆菌SNK-6组（T1：1.0×10⁶ CFU/g）和高剂量唾液乳杆菌SNK-6组（T2：1.0×10⁷ CFU/g）。结果表明，T1组的采食量和破蛋率显著高于Con组（p < 0.05）。同时，肠道黏膜免疫相关基因的表达显著上调。16S rRNA基因测序表明，补充唾液乳杆菌SNK-6对盲肠微生物群的α-多样性无显著差异，仅在β-多样性上呈现趋势性差异（p = 0.07）。进一步利用LEfSe和随机森林分析确定肠杆菌科、RF39菌目、苍白杆菌属和真杆菌属为Con组和T1组之间的生物标志物。在T1组和T2组中相对丰度和节点度较高的苍白杆菌属与盲肠扁桃体中TLR-6、IL-10、MHC-II和CD40的表达呈显著正相关，可能在激活宿主肠道黏膜免疫反应中起关键作用。总体而言，日粮补充唾液乳杆菌SNK-6可能通过调节盲肠微生物组成发挥免疫调节功能。然而，免疫反应的变化可能是以相应的生产性能为代价的，这在实际应用中需要权衡。
