蒙古族儿童肠道菌群结构特征分析

Intestinal flora structure of obese Mongolian children based on DGGE and real-time PCR

目的比较不同体质量指数(body mass index,BMI)蒙古族儿童肠道菌群结构特征,为蒙古族儿童消化代谢研究提供基础数据。方法采用整群抽样方法,调查包头市某地区7~12岁蒙古族儿童410名,严格按照纳入标准并进行同年龄和同性别1∶1匹配,筛选出肥胖、超重和正常体重儿童各30名为研究对象,采用试剂盒法提取研究对象粪便基因组DNA,通过聚合酶链式反应变性梯度凝胶电泳(poclymerase chain reaction denaturing gradient gel electrophoresis,PCRDGGE)分析不同BMI分组蒙古族儿童肠道菌群的多样性,进而通过实时荧光定量PCR(real-time PCR)对肠道内优势菌群脆弱拟杆菌属、梭菌属、双歧杆菌属和乳杆菌属进行定量检测。结果 PCR-DGGE电泳图谱显示,不同BMI分组的蒙古族儿童肠道菌群构成差异有统计学意义。肥胖组细菌群落丰富度(7.40±0.55)低于正常体重组(11.00±1.22)和超重组(12.40±2.51)(F=14.71,P<0.05);肥胖组香农多样性指数(1.92±0.07)低于正常体重组(2.29±0.10)和超重组(2.33±0.21)(F=15.08,P<0.05)。real-time PCR结果显示,随着BMI增大,蒙古族儿童肠道内脆弱拟杆菌属、双歧杆菌属的数量呈递减趋势,而梭菌属的数量呈递增趋势(F值分别为3.99,6.84,6.82,P值均<0.05);乳杆菌属的数量在蒙古族肥胖组、超重组和正常体重组儿童之间差异无统计学意义(P>0.05)。结论不同BMI分组的蒙古族儿童肠道菌群构成存在差异。肠道菌群可能参与了蒙古族儿童肥胖的发生发展过程。

Objective To compare the intestinal flora of Mongolian children with different body mass index（ BMI） in a certain area of Baotou city.Methods A cluster sampling method was used to investigate 410 Mongolian children aged 7 to 12 years old in Baotou City.Each weight category group（ obesity,overweight and normal weight） included 30 cases and age-,sex-matched30 control children.The fecal genomic DNA was extracted by the kit method.The diversity of intestinal flora of Mongolian children with different BMI groups was analyzed by PCR-DGGE.The real-time PCR was used to detect the dominant bacteria in intestinal tract,including Bacteroides,Clostridium,Bifidobacterium and Lactobacillus.Results PCR-DGGE electrophores showed that there were differences in the composition of intestinal flora of Mongolian children with different BMI groups.The species richness of obesity group（ 7.40± 0.55） was significantly lower than that of normal body weight group（ 11.00 ± 1.22） and overweight group（ 12.40±2.51）（ P〈0.05）; the Shannon diversity index of obese group（ 1.92±0.07） was lower than that of normal body weight group（ 2.29±0.10） and overweight group（ 2.33± 0.21）（ P〈0.05）.Results of real-time PCR showed that with the increase of BMI,the number of Bifidobacterium and Bacteroidesin in different BMI groups of Mongolian children decreased（ P〈0.05）,while the number of Clostridium increased（ P〈0.05）.There was no significant difference in the number of Lactobacillus among the three groups（ P〉0.05）.Conclusion There are differences in the composition of intestinal fiora of Mongolian children with different BMI groups.It suggests that intestinal flora may be involved in the occurrence and development of obesity in Mongolian children.