背景:对家禽施用罗伊利氏杆菌的益生菌菌株已被证明可以改善家禽的性能和健康。罗伊氏乳杆菌分类群的一些菌株可以产生罗伊林,一种来自甘油转化的广谱抗微生物化合物,对肠杆菌具有高抑制活性。然而,关于甘油在复杂的鸡盲肠微生物群中的代谢以及甘油的作用知之甚少,单独或与罗伊乳杆菌联合使用。在这项研究中,我们研究了罗伊氏乳杆菌PTA5_F13,一种高产罗伊特林的鸡菌株和甘油的作用,单独或组合,使用最近开发的模拟鸡盲肠发酵的连续PolyFermS模型对肉鸡盲肠微生物群组成和活性进行研究。
方法:用来自不同动物的固定化盲肠微生物群接种三个独立的PolyFermS鸡盲肠微生物群模型,并连续操作。在连续接种相同微生物群的平行第二阶段反应器中测试了两种额外水平的甘油(50和100mM)的影响,其中每天补充或不补充鸡来源的罗伊氏乳杆菌PTA5_F13(107CFU/mL终浓度)。我们使用16SrRNA元编码和qPCR分析了复杂的鸡肠道微生物群结构和动力学。微生物代谢产物,短链和支链脂肪酸,通过HPLC分析来自稳定反应器的流出物样品中的甘油和reuterin产物。
结果:单独补充100mM甘油并与罗伊氏乳杆菌PTA5_F13组合导致三种模拟的微生物群中丁酸产生的可重复增加(增加18-25%)。单独的甘油还导致三个微生物群中的两个中的肠杆菌科减少,但单独的罗伊乳杆菌没有检测到效果。当两种治疗方法结合使用时,所有微生物群定量抑制肠杆菌科,包括在最后一个模型中,肠杆菌科的初始浓度非常高。此外,在联合处理的废水中测量到显著的1,3-PDO积累,证实了甘油通过reuterin途径的转化。补充甘油,独立于罗伊氏乳杆菌的添加,不影响微生物群落多样性。
结论:甘油诱导了所有测试微生物群的稳定和可重复的产丁活性,并诱导了对肠杆菌的抑制作用,当每天添加产生罗伊林的罗伊氏乳杆菌时,这种抑制作用得到了加强。我们的体外研究表明,罗伊氏乳杆菌PTA5_F13和甘油的共同应用可能是通过增强代谢和对肠杆菌科的保护来促进鸡肠道健康的有用方法。
BACKGROUND: Administering probiotic strains of Limosilactobacillus reuteri to poultry has been shown to improve poultry performance and health. Some strains of L. reuteri taxa can produce reuterin, a broad-spectrum antimicrobial compound from glycerol conversion, with high inhibitory activity against enterobacteria. However, little is known about the metabolism of glycerol in the complex chicken cecal microbiota nor the effect of glycerol, either alone or combined with L. reuteri on the microbiota. In this study, we investigated the effect of L. reuteri PTA5_F13, a high-reuterin-producing chicken strain and glycerol, alone or combined, on broiler chicken cecal microbiota composition and activity using the continuous PolyFermS model recently developed to mimic chicken cecal fermentation.
METHODS: Three independent PolyFermS chicken cecal microbiota models were inoculated with immobilized cecal microbiota from different animals and operated continuously. The effects of two additional levels of glycerol (50 and 100 mM) with or without daily supplementation of chicken-derived L. reuteri PTA5_F13 (107 CFU/mL final concentration) were tested in parallel second-stage reactors continuously inoculated with the same microbiota. We analyzed the complex chicken gut microbiota structure and dynamics upon treatment using 16S rRNA metabarcoding and qPCR. Microbiota metabolites, short-chain and branched-chain fatty acids, and glycerol and reuterin products were analyzed by HPLC in effluent samples from stabilized reactors.
RESULTS: Supplementation with 100 mM glycerol alone and combined with L. reuteri PTA5_F13 resulted in a reproducible increase in butyrate production in the three modelled microbiota (increases of 18 to 25%). Glycerol alone resulted also in a reduction of Enterobacteriaceae in two of the three microbiota, but no effect was detected for L. reuteri alone. When both treatments were combined, all microbiota quantitatively inhibited Enterobacteriaceae, including in the last model that had very high initial concentrations of Enterobacteriaceae. Furthermore, a significant 1,3-PDO accumulation was measured in the effluent of the combined treatment, confirming the conversion of glycerol via the reuterin pathway. Glycerol supplementation, independent of L. reuteri addition, did not affect the microbial community diversity.
CONCLUSIONS: Glycerol induced a stable and reproducible butyrogenic activity for all tested microbiota and induced an inhibitory effect against Enterobacteriaceae that was strengthened when reuterin-producing L. reuteri was spiked daily. Our in vitro study suggests that co-application of L. reuteri PTA5_F13 and glycerol could be a useful approach to promote chicken gut health by enhancing metabolism and protection against Enterobacteriaceae.