高品质低聚木糖对小鼠肠道菌群及免疫功能影响的研究

摘 要 目的：研究高木二糖、木三糖含量的低聚木糖对小鼠肠道菌群及免疫功能的影响。方法：利用高木二糖、木三糖含量的低聚木糖和普通低聚木糖为碳源,分别接种两种双歧杆菌和两种乳杆菌,测定其48 h活菌数,比较两种低聚木糖对双歧杆菌和乳杆菌生长的影响。以BALB/C小鼠为试验对象,在连续给予不同剂量[100、200 mg·（kg·bw）-1]的两种低聚木糖14 d后,利用选择培养基测定小鼠粪便中双歧杆菌、乳杆菌、肠球菌、肠杆菌和产气荚膜菌的菌数,同时测定粪便中短链脂肪酸乙酸、丙酸和丁酸的含量,并利用酶联免疫吸附测定法（ELISA）检测小鼠血清中免疫球蛋白IgG、IgA和IgM的含量。结果：与普通的低聚木糖相比,高木二糖、木三糖含量的低聚木糖对双歧杆菌和乳杆菌具有更强的增殖作用。连续给予低聚木糖14 d后,与普通低聚木糖组相比,高木二糖、木三糖含量的低聚木糖对小鼠肠道内双歧杆菌和乳杆菌具有更强的增殖作用,而且小鼠肠道代谢产生的乙酸、丙酸和丁酸分别提高了24.4%、50%和36.4%。与模型组相比,两种低聚木糖都增加了小鼠血清中IgG和IgM的含量,并且与普通低聚木糖高剂量组相比,高木二糖、木三糖含量低聚木糖高剂量组的IgG和IgM含量分别提高了6.9%和17.5%。结论：木二糖和木三糖相比于低聚木糖的其他组分具有更强的生物活性,为高品质低聚木糖的开发及应用提供了依据。

Effects of High-quality Xylo-oligosaccharides on Intestinal Microbiota and Immune Function in Mice

Objective: To study the effects of xylo-oligosaccharides with high contents of xylobiose/xylotriose on intestinal flora and immune function in mice. Methods: Using xylo-oligosaccharides with high contents of xylobiose/xylotriose and commercially available xylo-oligosaccharides as carbon sources, two strains of bifidobacterium and two strains of lactobacillus were inoculated separately. After 48 h, the viable cell counts were measured to compare the influence of the two types of xylo-oligosaccharides on the growth of bifidobacterium and lactobacillus. Two types of xylo-oligosaccharides were administered into BALB/C mice at different doses [100 and 200 mg·(kg·bw)-1] continuously for 14 days. The bacterial counts of bifidobacterium, lactobacillus, enterococcus, escherichia coli and clostridium perfringens in the mice feces were determined. Furthermore, the concentrations of short-chain fatty acids (acetic acid, propionic acid and butyric acid) in the feces were measured. The levels of immunoglobulins IgG, IgA and IgM in the mouse serum were assessed using enzyme-linked immunosorbent assay (ELISA). Results: Compared to commercially available xylo-oligosaccharides, xylo-oligosaccharides with high xylobiose/xylotriose contents exhibited stronger proliferative effects on bifidobacterium and lactobacillus. After continuous administration of xylo-oligosaccharides for 14 days, xylo-oligosaccharides with high xylobiose/xylotriose contents also exhibit stronger proliferative effects on bifidobacterium and lactobacillus in the mouse intestine. Furthermore, the production of acetic acid, propionic acid, and butyric acid in the mouse intestine increased by 24.4%, 50%, and 36.4% respectively. Additionally, xylo-oligosaccharides with high xylobiose/xylotriose contents showed an increase of 6.9% and 17.5% in IgG and IgM levels, respectively. Conclusion: Xylobiose and xylotriose possess stronger biological activity than other components of xylo-oligosaccharides, providing a rational basis for the development and application of high-quality xylo-oligosaccharides.