Studies on induction of anti-viral substances by lactic acid bacteria adhering to mucosal surface of intestine.

我们没有任何有效的策略来预防引起腹泻的病毒感染。益生菌是微生物细胞制剂或微生物细胞的组成部分，对宿主的健康和福祉具有有益影响。选定的益生菌已被证明对人类有重大的健康益处，因此有几种特征良好的菌株可供人类使用，以降低胃肠道感染的风险或治疗此类感染。本项目的目的是检测粘附性乳酸菌是否有能力在肠粘膜表面诱导抗病毒物质。我们以前曾提出，一些粘附性菌株干扰了引起腹泻的病毒的传播。本研究以牛冠状病毒和牛病毒性腹泻病毒为模型病毒，证实了部分乳酸菌对牛冠状病毒和牛病毒性腹泻病毒的抗病毒作用。此外，我们使用细胞计数试剂盒建立了抗病毒效果的检测方法，但该方法不能估计冠状病毒的滴度。某些乳酸菌菌株表现出抗BVDV活性，这是由于细菌细胞可以吸收病毒颗粒的机制所致。此外，通过常规方法发现了几株具有抗冠状病毒活性的菌株。

We do not have any effective strategies of prevention of virus infections inducing diarrhea. Probiotics are microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well-being of the host. Selected probiotics have been shown to have significant health benefits for humans, and thus several well-characterized strains are available for human use to reduce the risk of gastrointestinal infections or to treat such infections. The aim of this project is to examine whether adhesive lactic acid bacteria have an ability to induce anti-viral substances on the mucosal surface of intestine. We have previously suggested that some of adhesive strains interfered the propagation of virus inducing diarrhea. However, the mechanism is still unknown.In the present study, we confirmed anti-virus effects of some of the lactic acid bacteria against bovine corona virus and bovine viral diarrhea virus as a model virus. Moreover, we developed the assay for anti-virus effect using Cell Counting Kit-8, but the titre of corona virus could not be estimated by this assay. Certain strains of lactic acid bacteria showed anti-BVDV activity due to the mechanism by which the bacterial cells may absorb virus particles. Also, several strains were found to have an anti-corona virus activity by using a conventional method.