Enterotoxigenic Escherichia coli (ETEC) is the main infectious agent responsible for piglet post-weaning diarrhea with high mortality rates. Antimicrobials represent the current principal strategy for treating ETEC infections in pig farms, but the occurrence of multi-resistant bacterial strains has considerably increased in the last decades. Thus, finding non-antibiotic alternatives becomes a real emergency. In this context, we investigated the effect of a live yeast strain, Saccharomyces cerevisiae var boulardii CNCM I-1079 (SB) in an in vitro model of the weaning piglet colon implemented with a mucus phase (MPigut-IVM) inoculated with ETEC and coupled with an intestinal porcine cell line IPI-2I. We showed that SB was able to modulate the in vitro microbiota through an increase in Bacteroidiaceae and a decrease in Prevotellaceae families. Effluents collected from the SB treated bioreactors were able to mitigate the expression level of genes encoding non-gel forming mucins, tight junction proteins, innate immune pathway, and pro-inflammatory response in IPI-2I cells. Furthermore, SB exerted a significant protective effect against ETEC adhesion on porcine IPEC-J2 intestinal cells in a dose-dependent manner and showed a positive effect on ETEC-challenged IPEC-J2 by lowering expression of genes involved in pro-inflammatory immune responses. Our results showed that the strain SB CNCM I-1079 could prevent microbiota dysbiosis associated with weaning and protect porcine enterocytes from ETEC infections by reducing bacterial adhesion and modulating the inflammatory response.

中文翻译：

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Saccharomyces Cerevisiae Var Boulardii CNCM I-1079 降低受产肠毒素大肠杆菌攻击的猪细胞炎症反应相关基因的表达，并影响断奶仔猪结肠体外模型中的细菌群落

产肠毒素大肠杆菌(ETEC) 是导致仔猪断奶后腹泻的主要传染源，死亡率很高。抗菌剂是目前治疗养猪场 ETEC 感染的主要策略，但在过去几十年中，多重耐药菌株的出现显着增加。因此，寻找非抗生素替代品成为真正的紧急情况。在此背景下，我们研究了活酵母菌株Saccharomyces cerevisiae var boulardii 的影响CNCM I-1079 (SB) 在断奶仔猪结肠的体外模型中，采用接种 ETEC 并与肠道猪细胞系 IPI-2I 结合的粘液期 (MPigut-IVM) 实施。我们表明 SB 能够通过增加拟杆菌科和减少普氏菌科来调节体外微生物群家庭。从 SB 处理的生物反应器收集的流出物能够降低编码非凝胶形成粘蛋白、紧密连接蛋白、先天免疫途径和 IPI-2I 细胞中促炎反应的基因的表达水平。此外，SB 以剂量依赖性方式对 ETEC 粘附在猪 IPEC-J2 肠细胞上发挥显着的保护作用，并通过降低参与促炎免疫反应的基因表达对 ETEC 攻击的 IPEC-J2 显示出积极作用。我们的结果表明，菌株 SB CNCM I-1079 可以通过减少细菌粘附和调节炎症反应来防止与断奶相关的微生物群失调，并保护猪肠细胞免受 ETEC 感染。