Di Rong, Vakkalanka Malathi S, Onumpai Chatchaya, Chau Hoa K, White Andre, Rastall Robert A, Yam Kit, Hotchkiss Arland T
Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA.
Department of Food Science, Rutgers, the State University of New Jersey, 60 Dudley Road, New Brunswick, NJ 08901, USA.
Food Chem. 2017 Jul 15;227:245-254. doi: 10.1016/j.foodchem.2017.01.100. Epub 2017 Jan 21.
Shiga toxin (Stx)-producing, food-contaminating Escherichia coli (STEC) is a major health concern. Plant-derived pectin and pectic-oligosaccharides (POS) have been considered as prebiotics and for the protection of humans from Stx. Of five structurally different citrus pectic samples, POS1, POS2 and modified citrus pectin 1 (MCP1) were bifidogenic with similar fermentabilities in human faecal cultures and arabinose-rich POS2 had the greatest prebiotic potential. Pectic oligosaccharides also enhanced lactobacilli growth during mixed batch faecal fermentation. We demonstrated that all pectic substrates were anti-adhesive for E. coli O157:H7 binding to human HT29 cells. Lower molecular weight and deesterification enhanced the anti-adhesive activity. We showed that all pectic samples reduced Stx2 cytotoxicity in HT29 cells, as measured by the reduction of human rRNA depurination detected by our novel TaqMan-based RT-qPCR assay, with POS1 performing the best. POS1 competes with Stx2 binding to the Gb3 receptor based on ELISA results, underlining the POS anti-STEC properties.
产志贺毒素（Stx）的食品污染大肠杆菌（STEC）是一个主要的健康问题。植物来源的果胶和果胶寡糖（POS）被认为是益生元，可保护人类免受Stx侵害。在五个结构不同的柑橘果胶样品中，POS1、POS2和改性柑橘果胶1（MCP1）在人类粪便培养物中具有双歧生成作用，发酵能力相似，且富含阿拉伯糖的POS2具有最大的益生元潜力。在混合批次粪便发酵过程中，果胶寡糖也促进了乳酸杆菌的生长。我们证明，所有果胶底物对大肠杆菌O157:H7与人HT29细胞的结合均具有抗粘附作用。较低的分子量和去酯化作用增强了抗粘附活性。我们表明，通过我们基于新型TaqMan的RT-qPCR测定法检测到的人rRNA脱嘌呤减少来衡量，所有果胶样品均降低了HT29细胞中Stx2的细胞毒性，其中POS1表现最佳。基于ELISA结果，POS1与Stx2竞争结合Gb3受体，突出了POS的抗STEC特性。
