目的:使用荧光原位杂交-流式细胞计数法(FISH-FC)测定灌胃自筛菌株嗜酸乳杆菌KLDS1.8701与植物乳杆菌KLDS1.0355混合液对抗生素性肠道菌群失衡小鼠的影响,并初步研究其发挥作用的机制。方法:在体外实验中,测定上述两株菌对肠道病原菌的抑制作用,并探讨其作用机理。在体内实验中,采用随机饮用盐酸克林霉素水溶液(2.8mg/mL)的方法建立抗生素性肠道菌群失衡小鼠模型,并使用FISH-FC方法测定小鼠粪便中总厌氧菌、球形梭菌属(Clostridium coccoides-Eubacterium rectale)、肠杆菌(Enterobacteria)、拟杆菌属(Bacteroides-Prevotella)的数量变化,以此判断模型是否建立成功。之后,灌胃嗜酸乳杆菌KLDS1.8701和植物乳杆菌KLDS1.0355的混合液(活菌数分别为107、108、109CFU/mL),以生理盐水为对照,采用上述方法评价混合菌液对小鼠模型的影响。结果:与对照组相比,灌胃混合菌液组可迅速恢复肠道菌群平衡(P〈0.01),产生作用的效应剂量为107CFU/mL。结论:直接的抗微生物效应可能是该混合菌液调节肠道菌群平衡的机制之一。
Objective: To explore the effect of mixed Lactobacillus acidophilus and Lactobacillus plantarum cultures(1:1,V/V) on intestinal flora disorder in mice by fluorescence in situ hybridization combined with flow cytometry(FISH-FC) and to elucidate the regulation mechanisms.Methods: The inhibitory activity of the mixture on pathogenic bacteria was determined in vitro.Antibiotic-associated diarrhea mouse model was established by giving specific-pathogen-free(SPF) mice drinking water containing clindamycin hydrochloride at the dose of 2.8 mg/mL for 7 days.Predominant bacteria such as Enterobacteriaceae,C.coccoides-E.rectale and Bacteroides-Prevotella were quantified by FISH-FC method.After diarrhea was successfully induced,the model mice were administered with the mixture of Lactobacillus acidophilus and Lactobacillus plantarum at different amounts of 107,108,109 CFU/mL by gavage.Sterile saline was used as the control.Results: Compared with the control,the administration of the mixture containing Lactobacillus acidophilus and Lactobacillus plantarum could result in the fast recovery of disordered intestinal flora(P 0.01).The effective dose was 107 CFU/mL.Conclusion: Direct antimicrobial effect may be one of the mechanisms for regulating intestinal flora disorder.