超重孕妇的肠道菌群与妊娠期糖尿病的关系

The relationship between Gut microbiota of overweight pregnant women and gestational diabetes mellitus

目的探讨超重和肥胖孕妇妊娠中期肠道菌群特征及其与妊娠期糖尿病(GDM)的关系。方法选取2019年11月至2020年6月在上海市第一人民医院产科门诊规律产检的88例妊娠中期孕妇作为研究对象。根据孕前体质量指数和是否伴有GDM分为四组组1未超重(孕前BMI<24.0kg/m^(2))未患GDM组;组2未超重患GDM组;组3超重或肥胖(孕前BMI≥24.0kg/m^(2))未患GDM组;组4超重或肥胖患GDM组。行OGTT当天收集新鲜粪便,利用Illumina Hiseq 2500平台针对细菌16S rRNA的V3-V4可变区进行DNA测序,并进行生物信息学分析。结果四组孕妇的肠道菌群构成不同,其中组4厚壁菌门占比最低为36%,拟杆菌门占比最高约50%。未患GDM孕妇中,超重孕妇(组3)的HOMA-IR显著高于体重正常孕妇(组2),但两组孕妇肠道菌群构成相似;而同患GDM孕妇中,超重(组4)和体重正常(组1)孕妇菌群构成差异显著,但HOMA-IR无差异。菌群与血糖水平、胰岛素水平存在不同的相关性。结论孕前超重或肥胖且患GDM的孕妇肠道菌群构成明显不同于其他三组孕妇。肠道菌群的改变可能是孕前BMI≥24kg/m^(2)的孕妇患GDM的重要原因。

Objective:To investigate the characteristics of gut microbiota in the second trimester and its relationship with gestational diabetes in overweight and obese pregnant women.Methods:A total of 88 pregnant women who underwent prenatal examination regularly in the Obstetrical Clinic of Shanghai General Hospital from November 2019 to June 2020 were selected as subjects.All the participants were divided into four groups according to their BMI and blood glucose state.group 1:pregnant women with BMI<24kg/m^(2) and without GDM;group 2:pregnant women with BMI<24kg/m^(2) and GDM;group 3:BMI≥24kg/m^(2) and without GDM;group 4:BMI≥24kg/m^(2) and with GDM.Their fresh feces were collected on the day of oral glucose tolerance test.The V3-V4 variable region of bacterial 16S rRNA was sequenced by DNA on the platform of Illumina Hiseq 2500,and bioinformatics analysis was carried out.Results:The composition of intestinal flora of pregnant women in four groups was different,among which the proportion of Firmicutes in group 4 was the lowest 36%.Bacteroidetes accounted for 50.1%.In pregnant women without GDM,the HOMA-IR of overweight pregnant women(group 3)was significantly higher than that of normal weight pregnant women(group 2),but the composition of intestinal flora of pregnant women in both groups was similar.Among pregnant women with GDM,there was significant difference in the composition of bacterial flora between overweight(group 4)and normal weight(group 1)pregnant women,but no difference was found in HOMA-IR.There were different correlations between flora and blood glucose and insulin levels.Conclusion:Pregnant women diagnosed GDM with overweight and obesity before pregnancy had significantly different intestinal flora composition than those in other three groups.Changes in intestinal flora may be an important cause of GDM in pregnant women with a BMI≥24kg/m^(2) before pregnancy.