无下尿路症状的女性2型糖尿病周围神经病变患者的尿液菌群特征

Characteristics of urinary microflora in women with type 2 diabetic peripheral neuropathy without lower urinary tract symptoms

目的:探讨无下尿路症状的女性2型糖尿病周围神经病变(DPN)患者的尿液菌群特征。方法:采用横断面调查研究,收集南方医科大学南方医院2017年5月至2018年8月收治的2型糖尿病且无下尿路症状的女性患者30例,17例合并糖尿病周围神经病者为DPN组,13例未合并糖尿病周围神经病变者为nDPN组。两组患者均行神经传导功能检查和美国泌尿外科学会症状指数问卷(AUA-SI)。收集两组患者的清洁中段尿标本并进行DNA提取,采用Illumina测序平台进行扩增和高通量测序,原始数据导入QI-IME软件分析样本微生物的α和β多样性,采用LEfSe软件分析两组间具有显著差异的菌群。结果:DPN组糖尿病病程明显短于nDPN组[(4.12±3.28)年与(8.03±6.11)年,P=0.03]。DPN组视网膜病变例数明显多于nDPN组(6例与0例,P=0.03),两组间其余临床资料及生化指标差异均无统计学意义(P>0.05)。α多样性分析结果显示,与nDPN组相比,DPN组的尿液菌群丰富度显著下降(sobs指数67.24±40.25与108.69±57.18,P=0.03;chao指数81.36±47.99与122.55±55.70,P=0.04;ace指数88.58±55.03与125.78±53.03,P=0.04),但两组间群落多样性差异无统计学意义(shannon系数1.53±1.11与1.91±0.87,P=0.26;simpson指数0.48±0.34与0.34±0.20,P=0.41)。β多样性分析结果显示,DPN组与nDPN组的菌群结构差异无统计学意义(P>0.05)。LEfSe分析结果显示,在菌科水平,DPN组支原体科相对丰度显著高于nDPN组(Metastats值0.52±0.01与0.01±0.00001,P=0.02);在菌属水平,DPN组芽孢杆菌属、杜氏菌属、纤毛菌属、变形杆菌属、丙酸菌属、假黄色单胞菌属、蛭弧菌属、不可培养土壤细菌属等8个菌属相对丰度均降低(P<0.05)。结论:无下尿路症状的女性2型糖尿病周围神经病变患者的尿液菌群明显不同于无周围神经病变患者,其菌群丰富度降低,支原体科细菌可能为DPN患者的潜在生物标志物。

Objective To investigate the characteristics of urinary microflora in women with type 2 diabetic peripheral neuropathy without lower urinary tract symptoms.Methods By completing nerve conduction function and the American Urological Association Symptom Index questionnaire(AUA-SI),a total of 30 cases of women hospitalized with type 2 diabetes and no symptoms of lower urinary tract from May 2017 to August 2018 were included.17 patients with diabetic peripheral neuropathy were assigned to the DPN group,and 13 patients without diabetic peripheral neuropathy were assigned to the nDPN group.Urine specimens were collected from clean catch midstream urine and processed for extracting DNA.Microbial diversity and composition were analyzed using the Illumina sequencing platform targeting to 16S rDNA gene.Sequencing reads were processed by QIIME.LEfSe algorithm was used to analyze the flora with significant differences between the two groups.Results The duration of diabetes in the DPN group was lower than that in the nDPN group[(4.12±3.28)years vs.(8.03±6.11)years,P=0.03],and the retinopathy cases were more in the DPN group than those in the nDPN group(6 vs.0,P=0.03).Except for above two indicators,there was no significant difference in demographic characteristics between DPN group and nDPN group(P>0.05).The urinary microenvironment of DPN was characterized by increased bacterial richness(sobs index,chao index and aec index,67.24±40.25 vs.108.69±57.18;81.36±47.99 vs.122.55±55.70;88.58±55.03 vs.125.78±53.03,all P<0.05)and by the enrichment of Mycoplasmataceae(Metastats value:0.52±0.01vs.0.01±0.00001,P=0.02).Beta diversity showed that no significant difference of bacterial composition was found between these two group(P>0.05).LEfSe analysis showed that at the genus level,the relative abundance of eight genera(e.g.,Bacillus,Duganella,Leptotrichia,Proteus,Propionibacterium,Pseudoxanthomonas,Bdellovibrio and uncultured_soil_bacterium)in DPN group decreased at the level of genus(P<0.05).Conclusions Female patients with type 2 diabetes without lower urinary tract symptoms of peripheral neuropathy exhibit a different microbial community compared to nDPN controls.Mycoplasmataceae may be a potential biomarker for patients with DPN.