Rao R K, Samak G
Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA.
DVS College of Arts and Science, Shimoga, India.
Curr Nutr Food Sci. 2013 May 1;9(2):99-107. doi: 10.2174/1573401311309020004.
Probiotics are beneficial bacteria present in various dietary components and many of these colonize in the human and animal intestine. In the gut probiotics help the host by assisting in maintenance of normal mucosal homeostasis. Probiotics not only help maintain normal function of the gut mucosa, but also protect mucosa from injurious factors such as toxins, allergens and pathogens. The beneficial effect of probiotics is mediated by multiple mechanisms, including cytoprotection, cell proliferation, cell migration, resistance to apoptosis, synthesis of proteins and gene expression. One of the important cytoprotective effects of probiotics in the intestinal mucosa is to strengthen the epithelial tight junctions and preservation of mucosal barrier function. Probiotics not only enhance barrier function by inducing synthesis and assembly of tight junction proteins, but also preventing disruption of tight junctions by injurious factors. Bioactive factors released by probiotics trigger activation of various cell signaling pathways that lead to strengthening of tight junctions and the barrier function. This article reviews and summarizes the current understanding of various probiotics that are involved in the protection of gut barrier function, highlights the cellular and molecular mechanisms involved in the protective effect and addresses the clinical implications of probiotic supplementation.
益生菌是存在于各种饮食成分中的有益细菌，其中许多会在人和动物的肠道中定殖。在肠道中，益生菌通过协助维持正常的黏膜稳态来帮助宿主。益生菌不仅有助于维持肠道黏膜的正常功能，还能保护黏膜免受毒素、过敏原和病原体等有害因素的侵害。益生菌的有益作用是通过多种机制介导的，包括细胞保护、细胞增殖、细胞迁移、抗凋亡、蛋白质合成和基因表达。益生菌在肠道黏膜中的重要细胞保护作用之一是加强上皮紧密连接并维持黏膜屏障功能。益生菌不仅通过诱导紧密连接蛋白的合成和组装来增强屏障功能，还能防止有害因素破坏紧密连接。益生菌释放的生物活性因子会触发各种细胞信号通路的激活，从而导致紧密连接和屏障功能增强。本文综述并总结了目前对参与保护肠道屏障功能的各种益生菌的认识，强调了保护作用所涉及的细胞和分子机制，并探讨了补充益生菌的临床意义。
