Bacillus licheniformis CK1及Lactobacillus reuteri Pg4之潛力益生性研究

Abstract

目前益生菌的研究主要專注在腸道功能的保健。一般認為益生菌夠維持腸道菌相，並且強化寄主腸道皮膜屏障。先前的研究發現經由攝食Bacillus licheniformis CK1添加的飼料能夠改善黴菌毒素在豬隻上所造成的生理障礙。而 Lactobacillus reuteri Pg4可增厚雞隻腸道黏膜及增加微絨毛的高度。然而，CK1及Pg4 對於腸道上皮細胞的影響機制並未有更深的研究。從in vitro實驗中發現 Pg4及CK1對於腸道上皮細胞有不同的助益機制。在Caco-2及IPEC-1單層膜細胞上，我們發現Pg4透過增加ZO-1及occludin等腸道上皮細胞緊密連接蛋白的表現，來幫助維持腸道單層膜的穩定性，進而延緩病原菌造成的傷害。而 CK1 則能夠顯著降低 Salmonella enterica serovar Typhimurium及Escherichia coli O157：H7腸道病原菌於IPEC-1及Caco-2細胞的吸附能力。我們的結果顯示了益生菌與寄主腸上皮細胞的交互作用，以及益生菌與病原菌之間可能的競爭機制。而本實驗利用分別來自豬隻及人類的上皮細胞模型探討CK1及Pg4可能的益生特性，可以提供菌株更多元的應用方向，結果也發現CK1及Pg4擁有各自優秀的益生特性，未來可以從複合益生菌的角度來研究在人類營養補充品或是飼料添加物的應用。

The research related to probiotics has primarily been focused on improving intestine health, including the maintenance of the intestinal microbiota and modulation of host intestinal barrier integrity. As reported, by feeding with Bacillus licheniformis CK1, the reproductive disorder of pig caused by zearalenone toxin can be ameliorated. The other putative probiotic, like Lactobacillus reuteri Pg4, has been demonstrated to thicken the mucus layer and increase the height of microvilli, indicating that Pg4 enhances the function of host intestinal barrier. However, the detail of mechanisms for CK1 and Pg4 regulation in the barrier function remains unclear. Here, we showed that CK1 and Pg4 possess different probiotic properties, which are related to inhibit the adhesive ability of pathogens and enhance the barrier function of intestinal cells, respectively. These results indicate that CK1 reduces the amounts of pathogens, including Salmonella enterica serovar Typhimurium and Escherichia coli O157：H7, binding to the epithelial cells. Furthermore, Pg4 elevates the expression of ZO-1 and occludin, which contributes to the stability of intestinal monolayer and prevents the disruption from pathogen infection. In this study, we demonstrated that how CK1 and Pg4 are likely to function with epithelial monolayer model, and the competitive interaction with pathogen. In conclusion, both CK1 and Pg4 have their own novel properties for helping intestinal cells. Therefore, CK1 and Pg4 provide a perspective of combination of these probiotics which may apply in human dietary supplement or animal feed additives.