School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
Chr. Hansen A/S, 2970 Hoersholm, Denmark.
Nutrients. 2020 Jun 8;12(6):1719. doi: 10.3390/nu12061719.
Probiotic-host interaction can be cell-to-cell or through metabolite production. Dead (inactive) organisms could interact with the host, leading to local effects and possible health benefits. This research examined the effects of live and heat-inactivated subsp. , BB-12 (BB-12) and (LGG) on cultured Caco-2 cells focusing on epithelial integrity and production of inflammatory mediators. Live organisms increased transepithelial electrical resistance (TEER), a barrier-integrity marker, with LGG having a greater effect than BB-12. When mildly heat-treated, both organisms had a more modest effect on TEER than when alive. When they were heat-inactivated, both organisms had only a limited effect on TEER. Neither live nor heat-inactivated organisms affected production of six inflammatory mediators produced by Caco-2 cells compared to control conditions. Pre-treatment with heat-inactivated LGG or BB-12 did not alter the decline in TEER caused by exposure to an inflammatory cocktail of cytokines. However, pre-treatment of Caco-2 cells with heat-inactivated organisms alone or their combination decreased the production of interleukin (IL)-6, IL-18, and vascular endothelial growth factor. To conclude, while the live organisms improve the epithelial barrier using this model, neither live nor heat-inactivated organisms directly elicit an inflammatory response by the epithelium. Pre-treatment with heat-inactivated BB-12 or LGG can reduce some components of the response induced by an inflammatory stimulus.
益生菌-宿主的相互作用可以是细胞间的，也可以通过代谢产物的产生来实现。死（失活）的生物体可以与宿主相互作用，导致局部效应和可能的健康益处。本研究检测了活菌和热灭活亚种 BB-12（BB-12）和 LGG（LGG）对培养的 Caco-2 细胞的影响，重点关注上皮完整性和炎症介质的产生。活菌增加了跨上皮电阻（TEER），这是一个屏障完整性标志物，LGG 的效果比 BB-12 更强。当轻度热处理时，与活菌相比，这两种生物体对 TEER 的影响更为温和。当它们被热灭活时，这两种生物体对 TEER 的影响有限。与对照条件相比，无论是活菌还是热灭活的生物体都不会影响 Caco-2 细胞产生的六种炎症介质的产生。与暴露于细胞因子炎症混合物相比，用热灭活的 LGG 或 BB-12 预处理不会改变 TEER 的下降。然而，用热灭活的生物体单独或它们的组合预处理 Caco-2 细胞可降低白细胞介素（IL）-6、IL-18 和血管内皮生长因子的产生。总之，虽然活生物体在该模型中改善了上皮屏障，但无论是活菌还是热灭活的生物体都不会直接引起上皮的炎症反应。用热灭活的 BB-12 或 LGG 预处理可以减少炎症刺激诱导的反应的一些成分。
