玉竹水提物对抗生素致菌群失调小鼠肠道乳糖酶活性及菌群多样性的影响

Effect of Polygonatum odoratum Aqueous Extract on Gut Lactase Activity and Microflora Diversity inDysbacteriosis Mice Induced by Antibiotic

目的本研究拟探究玉竹水提物对菌群失调小鼠的乳糖酶活性和肠道菌群多样性的影响。方法将SPF级雄性BALB/c小鼠随机分为4组,分别为对照组(control)、模型组(model)及玉竹低剂量(yzlow,1.56 g·kg^(-1)·d^(-1))和高剂量(yz-high,3.12 g·kg^(-1)·d^(-1))给药组,每组8只(对照组5只)。除对照组外,采用混合抗生素灌胃造模7天后,给药组连续灌胃玉竹7天,对照组与模型组给予等量无菌水。记录小鼠腹泻情况、体质量、摄食量的变化;检测结肠HE染色切片、结肠组织ZO-1蛋白、IL-6表达情况和血清LPS浓度;收集粪便,采用比色法测定乳糖酶活性,并运用16S rRNA高通量测序技术检测并分析肠道菌群的变化。结果抗生素干预7天后,与对照组相比,模型组小鼠大便稀软,体质量减轻、摄食量减少,肠道菌群多样性明显降低。第14天,模型组结肠可见溃疡伴有间质轻微充血水肿,ZO-1表达显著降低,IL-6表达显著升高,血清LPS显著升高,乳糖酶活性显著降低,肠道菌群多样性仍低于正常组;给药7天,与模型组相比,玉竹水提物降低了小鼠的腹泻率并促使体质量及摄食量回升,下调病理结肠组织损伤,ZO-1蛋白表达显著升高,降低结肠因子IL-6、血清LPS浓度。此外,玉竹水提物可显著上调乳糖酶活性,提高菌群失调小鼠的群落丰富度、多样性,表现为回调了菌群失调小鼠的3种差异菌门(上调厚壁菌门,下调变形菌门和拟杆菌门)与7种差异菌属(包括上调Rikenellaceae_RC9_gut_group属、Rikenella属、Colidextribacter属、norank_f__Lachnospiraceae属、norank_f__Oscillospiraceae属、Lachnospiraceae_NK4A136_group属,下调Alloprevotella属),上述菌丰度均与体质量、乳糖酶活性、血液LPS、结肠炎症因子IL-6呈显著相关。结论玉竹水提物能缓解由抗生素导致菌群失调引起的肠道屏障损伤和功能紊乱,其机制可能是通过调节肠道菌群结构。

Objective This study aimed to investigate the effects of P.odoratum extract on lactase activity and microflora diversity in mice with bacterial dysbacteriosis.Methods SPF male BALB/c mice were randomized into 4 groups:control,model,P.odoratum extract low dose(1.56 g·kg^(-1)·d^(-1))and high dose(3.12 g·kg^(-1)·d^(-1))treatment group.There were 8 mice in each group(5 in the blank group).In addition to the control group,after 7 days of intragastric administration of mixed antibiotics,the administration groups were given P.odoratum extract for 7 days,and the control group and the model group were given the same amount of sterile water.The changes of diarrhea,body weight and food intake of mice were recorded.The colon HE staining sections,ZO-1 protein,IL-6 expression,and serum LPS concentration were detected.Feces were collected for lactase activity and microbial diversity determination with 16S rRNA high-throughput sequencing technology.Results After 7 days of antibiotic intervention,compared with the control group,the mice in the model group had soft stool,weight loss,reduced food intake,and significantly reduced intestinal flora diversity.At the 14th day,in the model group,ulceration accompanied by slight interstitial congestion and edema was seen in the colon,ZO-1 expression was significantly reduced,IL-6 expression was significantly increased,serum LPS was significantly increased,lactase activity was significantly reduced,and intestinal flora diversity was still lower compared with the control group.After 7 days of administration,compared with the model group,P.odoratum reduced the diarrhea rate of mice,promoted a recovery of body weight and food intake,downregulated pathological colon tissue damage,significantly increased ZO-1 protein expression,and reduced colon factor IL-6 and serum LPS concentration.In addition,P.odoratum can significantly up-regulate lactase activity and improve the community richness and diversity of dysbacteriosis mice.It is shown that three phyla(up-regulated Firmicutes,down-regulated Proteobacteria and Bacteroidetes)and seven genera(up-regulated Rikenellaceae_RC9_gut_group,Rikenella,Colidextribacter,norank_f__Lachnospiraceae,norank_f__Oscillospiraceae,and Lachnospiraceae_NK4A136_group,downregulated Alloprevotella),the abundance of which was significantly correlated with body weight and lactase activity,serum LPS,and colon factor IL-6.Conclusion P.odoratum can alleviate the gut barrier injury and dysfunction caused by antibiotic induced dysbiosis,and its mechanism may be achieved by regulating microflora structure.