(1.量子高科(广东)生物有限公司, 广东 江门 529081;2.华南理工大学 生命科学研究院, 广东 广州 510006)
(1.Quantum Hi-Tech (Guangdong) Biological Co Ltd, Jiangmen 529081,China;2.Institutes for Life Sciences, South China University of Technology, Guangzhou 510006, China)
由于对于不同益生元的功效差异所知甚少,不同益生元往往被当作类似物应用于食品添加及临床干预。通过鉴定市场上常见的6种益生元(蔗果三糖、2′-岩藻糖基乳糖、低聚果糖、低聚半乳糖、低聚甘露糖、菊粉)在调节人体炎症免疫功能上的差异,为益生元的精准化应用提供指导方向和实验依据。用出血性大肠杆菌(enterohemorrhagic Escherichia coli O157:H7,EHEC)刺激人肠上皮细胞系HCT-8细胞构建肠上皮细胞炎症模型,检测6种益生元处理后NF-κB信号通路激活及下游细胞因子TNF-α 和IL-6表达情况以确定其对于细胞炎症的影响；从30名志愿者血液中通过密度梯度离心法分离单个核细胞,并于体外诱导产生树突状细胞以构建免疫细胞成熟分化模型,在诱导分化的过程中分别加入6种益生元,通过流式细胞术分析益生元处理后树突状细胞的成熟比例以确定不同益生元对于免疫细胞成熟分化的影响。研究发现:6种益生元只有2′-岩藻糖基乳糖、低聚半乳糖及蔗果三糖抑制人肠上皮细胞炎症响应,其余无明显影响；2′-岩藻糖基乳糖、蔗果三糖及菊粉促进树突状细胞成熟(促进成熟的志愿者比例分别为73.3%、57.1%、63.3%),而低聚半乳糖抑制树突状细胞成熟(抑制成熟的志愿者比例为73.3%)。这些结果表明不同益生元在调节人体炎症免疫方面具有不同的功能,益生元的添加需要根据人群身体情况特征精准化设计。
The functional differences among individual prebiotics are largely unknown, and different prebiotics are usually used as functional composition analogues for food addition and clinical intervention. To investigate the functional specificity of 6 widely-used prebiotics (GF2,2′-FL, FOS, GOS, MOS and inulin) on inflammation and immunity, which could provides guidance and experimental evidence for precise nutrition, a model of intestinal epithelial cell inflammation was firstly constructed by using EHEC (enterohemorrhagic Escherichia coli O157:H7) to stimulate HCT-8 cells. And the effects of six prebiotics on cell inflammation were analyzed via detecting the activation of NF-κB signaling pathway and expression levels of proteins TNF-α and IL-6 in its downstream. Then a in vitro dentritic cell maturation assay was constructed. Human dentritic cells were obtained by density gradient centrifugation, and used GM-CSF and IL-4 cytokines to stimulate PBMC (peripheral blood mononuclear cells) separated from 30 volunteers and treated with or without prebiotics. The effects of six prebiotics treatment on dentritic cells maturation were determined by comparing the proportion of mature dentritic cells through flow cytometry. The results showed that only 2′-FL, GOS and GF2 treatment could inhibit the EHEC-induced HCT-8 cell inflammation. In addition, 2′-FL, GF2 and inulin treatment promoted dentritic cells maturation (increase rate 73.3%, 57.1% and 63.3%, respectively), GOS treatment significantly inhibited dentritic cells maturation (decrease rate 73.3%). Therefore, these findings suggested that the effects on regulating immunity varied among different prebiotics and prebiotics addition required precise design according to the physical condition of individuals.