金耳多糖的结构及其对环磷酰胺致小鼠肠道菌群紊乱的调节作用

Structure of Tremella aurantialba Polysaccharide and Its Regulatory Effect on Cyclophosphamide-induced Intestinal Flora Disturbance in Mice

【目的】研究金耳多糖(Tremella aurantialba polysaccharide,TAP)对小鼠体内肠道菌群紊乱的影响。【方法】以金耳为原料提取TAP,采用凝胶色谱法、高效液相色谱法、红外光谱、紫外光谱分析TAP的结构,再基于环磷酰胺诱导肠道菌群紊乱的小鼠为模型,使用TAP进行干预,采用气相色谱—质谱法(GCMS)测量小鼠结肠内容物短链脂肪酸水平,采用粪便16S rRNA法分析小鼠粪便肠道菌群变化。【结果】TAP分子质量为1740 ku,为含有β-型糖苷键的吡喃型多糖,含微量蛋白质及核酸,主要由甘露糖、葡萄糖醛酸和葡萄糖3类单糖组成,占比分别为66.09%、9.51%和11.45%。动物试验表明:TAP处理能增加小鼠结肠内容物的短链脂肪酸含量,特别是乙酸和丁酸。粪便16S rRNA表明:TAP能够逆转肠道菌群紊乱,在门水平上,上调拟杆菌门(Bacteroidetes)菌群,下调厚壁菌门(Firmicutes)和变形菌门(Proteobacteria)菌群;在属水平上,上调拟杆菌属(Bacteroides)和乳杆菌属(Lactobacillus)菌群,下调螺杆菌属(Helicobacter)菌群。【结论】TAP有望作为一种潜在益生元调节肠道菌群,减少环磷酰胺对肠道微生物群的副作用。

[Purpose]To study the effect of Tremella aurantialba polysaccharide(TAP) on the disturbance of intestinal flora in mice.[Methods]TAP was extracted from T.aurantialba.The structure of TAP was analyzed by gel chromatography,high performance liquid chromatography,infrared spectroscopy and ultraviolet spectroscopy;then,based on cyclophosphamide-induced intestinal flora disorders in mice as a model for intervention with TAP,and the levels of short-chain fatty acids(SCFAs) in mouse colonic contents were measured by gas chromatography-mass spectrometry(GC-MS),and the intestinal flora of mice was analyzed by fecal 16S rRNA method.[Results]The molecular weight of TAP was 1 740 ku,it was a pyran-type polysaccharide containing β-glycosidic bonds,contained trace proteins and nucleic acids,mainly consisted of three types of monosaccharides:mannose,glucuronic acid and glucose,accounting for 66.09%,9.51% and 11.45%,respectively.Animal experiments showed that TAP treatment could increased the content of various SCFAs,especially acetic acid and butyric acid.Fecal 16S rRNA showed that TAP could reverse the disturbance of intestinal flora,up-regulated Bacteroidetes,down-regulated Firmicutes and Proteobacteria at the phylum level,and up-regulated Bacteroides and Lactobacillus,down-regulated Helicobacter at the genus level.[Conclusion]TAP holds promise as a potential prebiotic to modulate the gut microbiota and reduce the side effects of cyclophosphamide on the gut microbiota.