银耳多糖对免疫抑制小鼠肠道菌群的保护作用

Protective effect of tremella polysaccharides on gut microbiota of immunosuppressed mice

目的探究银耳多糖(TP)对环磷酰胺(Cy)造成的免疫抑制小鼠肠道菌群的保护作用。方法将18只SPF级雄性Balb/c小鼠随机分为空白对照(NC)组、模型对照(NaCl+Cy)组和银耳多糖恢复(TP+Cy)组,每组6只。NC组小鼠正常饮食饮水,不做任何处理;NaCl+Cy组小鼠每日腹腔注射环磷酰胺0.04 mg/g(以体质量计算,下同)、灌胃生理盐水0.3 mL;TP+Cy组每日腹腔注射环磷酰胺0.04 mg/g、灌胃银耳多糖0.1 mg/g,观察小鼠皮毛、行为、粪便等状态变化。10 d后处死全部小鼠,无菌条件下采集粪便,应用PCR-DGGE技术进行肠道菌群分析;收集脾、结肠等器官,应用苏木精-伊红染色(HE染色)进行脏器损伤分析。结果与NC组小鼠相比,NaCl+Cy组小鼠脾指数、胸腺指数下降;TP+Cy组小鼠脾指数、胸腺指数与NC组差异无统计学意义。PCR-DGGE结果显示,NaCl+Cy组小鼠肠道菌群多样性增加,优势菌群发生变化,疣微菌和紫单胞菌丰富度增加,乳杆菌、普雷沃菌、海洋螺菌、短杆菌和伯克菌丰富度减少;TP+Cy组小鼠肠道菌群多样性和优势菌群与NC组几乎没有差异。HE染色结果显示,NaCl+Cy组小鼠结肠、脾等脏器均有一定的炎症反应,但是TP+Cy组小鼠脏器未见明显损伤。结论银耳多糖对环磷酰胺造成的免疫抑制小鼠的脏器损伤、肠道菌群改变均有一定的保护作用。

Objective To investigate the protective effect of tremella polysaccharides(TPs)on the gut microbiota of immunosuppressed mice induced by cyclophosphamide(Cy).Methods Eighteen SPF-level male Balb/c mice were randomly divided into three groups(n=6):control(NC)group,cyclophosphamide model(NaCl+Cy)group and tremella polysaccharides(TP+Cy)group.The NC group was not treated;the NaCl+Cy group was intragastrically administered 0.3 ml saline solution and 0.04 mg/g(measured by body mass;the same hereinafter)Cy daily;the TP+Cy group was intragastrically administered 0.1 mg/g TP and 0.04 mg/g Cy daily.The changes in the behavior and stool of the mice were observed.After 10 days,all the mice were dissected;The stool,spleen,thymus and colon were collected for analysis of gut microbiota by using PCR-DGGE,or for HE staining to observe the damage and repair of organs.Results Compared with the NC group,the spleen and thymus indexes in NaCl+Cy group decreased,however there were no significant differences in the spleen and thymus indexes between NC group and TP+Cy group.The diversity of gut microbiota increased and the dominant bacterial had changed in NaCl+Cy group.The richness of Akkermansia and Parabacteroides increased while those of Pediococcus,Prevotella,Neptuniibacter,Brevibacterium and Polynucleobacter decreased.However there were no significant differences in the diversity of gut microbiota and dominant bacterial between NC group and TP+Cy group.HE staining showed that the colon and spleen of the mice in NaCl+Cy group had inflammation reaction,but the organs of the mice in TP+Cy group had no obvious damage.Conclusion Tremella polysaccharides have a certain protective effect on gut microbiota and organs in immunosuppressed mice induced by cyclophosphamide.