降解草酸盐益生菌的筛选及其体内功效评价

Screening of oxalate-degrading probiotics and evaluation of its function in vivo

过量草酸积累可引起人体高草酸尿症,从而引发肾结石。降解草酸是预防或缓解高草酸尿症的有效方法。从36株源于健康人体肠道和发酵乳制品的乳酸菌中筛选出1株草酸降解率达到83.6%的阴道乳杆菌(Lactobacillus vaginals)1F-6;利用急性毒性实验模型探究了L.vaginals 1F-6的安全性;建立高草酸尿症小鼠动物模型,通过测定尿草酸含量、尿素氮肌酸酐水平、SOD活性等指标,对L.vaginals 1F-6的降草酸效果进行分析评价。结果表明,灌胃L.vaginals 1F-6后小鼠体重和脏器指数与对照组没有显著性差异,表明L.vaginals 1F-6对小鼠无急性毒性作用;L.vaginals 1F-6可显著降低小鼠尿草酸含量、减少肾脏草酸钙晶体聚集,并有效缓解由草酸在肾脏过度蓄积引发的尿液离子浓度紊乱和肾氧化损伤,起到保护肾脏的作用。

Excessive accumulation of oxalate in human body can lead to hyperoxaluria,which could eventually result in the symptom of kidney stone.Degrading excessive oxalate in human body is one of an effective way to prevent or relieve hyperoxaluria.Thirty-six lactic acid bacteria strains were isolated from healthy human gut and fermented milks in our previous study.In this study,the strain with oxalate degradation ability were assessed among these 36 strains.Lactobacillus vaginals 1F-6 was screed out due to its high oxalate degradation activity,which could degrade 83.6%of the oxalate present in culture medium.Based on this,the safety assessments of L.vaginals 1F-6 were performed using the acute toxicological experiments in mouse model.Then,a mouse model of hyperoxaluria was established.The efficiency of oxalate degradation of L.vaginals 1F-6 in vivo was analyzed,which was assessed by measuring the index of urinary oxalate excretion,blood urea nitrogen,creatinine concentration and SOD activity,respectively.The results revealed that there were no differences in body weight and organ index between control group and gavage group,which proved that L.vaginals 1F-6 had no acute toxicity in mice.Besides,L.vaginals 1F-6 could significantly decrease the content of urinary oxalate in mice,reduce the aggregation of calcium oxalate crystal,and relieve the ionic disorder and renal the injury caused by oxalic acid overaccumulation in kidney,which had a positive effect of protection on kidney.These findings provided a foundation to develop the probiotic for preventing kidney stones caused by hyperoxaluria.