Connection Between Gut Microbiota And Gestational Diabetes Mellitus

Objective: To understand the characteristics of gut microbiota in pregnant women with gestational diabetes mellitus(GDM)and non-GDM through a case-control study;compare the difference of gut microbiota between GDM pregnant women and nonGDM pregnant women;explore other factors that affect the relative abundance of gut microbiota.Methods: The study subjects were pregnant women who were included in the Tongji Maternal and Child Health Cohort(TMCHC)from November 2016 to July 2018 and who had undergone the oral glucose tolerance test(OGTT).With informed consent,stool samples were received from 20 non-GDM pregnant women(control)and 19 GDM pregnant women(case),all of which met the inclusion criteria.The method of sampling stool samples was based on the International Human Microbiome Standards Project(IHMS),DNA was extracted using E.Z.N.A.? Stool DNA Kit(Omega Bio-TEk)stool extraction kit.The 16 S r DNA V3～V4 region was selected for sequencing and the sequencing platform was Illumina Miseq PE3000.Results:1.The average sampling gestational week of 39 samples was(28.28 ± 2.69)weeks.The average age of pregnant women in the control group was(29.55 ± 3.73)years,the average pre-pregnancy body mass index(BMI)was(20.09 ± 2.58)kg/m2,and the average percentage of body fat was(31.17 ± 4.72)%;the average age of pregnant women in the case group was(32.99 ± 4.85)years,the average BMI before pregnancy was(21.91 ± 2.51)kg/m2,and the average percentage of body fat was(34.83 ± 3.64)%.Compared with the control group,the average age of pregnant women in the case group was greater(P = 0.017),the average pre-pregnancy BMI was higher(P = 0.032),and the average percentage of body fat in the first trimester was larger(P = 0.010).2.Compared with the control group,the case group had a higher intake of coarse grains,aquatic products,vegetables and nuts,and less intake of rice flour products,poultry meat,soybeans,fruits and milk.3.There were no significant difference in Alpha and Beta diversity between the two groups of gut microbiota,but the distribution of bacteria in the case group was more different.4.The 39 samples with the highest relative abundance are Bacteroidetes(57.06%),followed by Firmicutes(35.40%).The relative abundance of Bacteroidetes(59.50%)in the case group was higher than that in the control group(51.23%),and the relative abundance of Firmicutes(33.80%)in the case group was lower than that in the control group(40.75%),but the differences were not significant.5.LEf Se analysis found that from the level of class to the level of genus,there were 18 nodes with different abundances between groups.The relative abundance of Gammaproteobacteria and its subordinate Enterobacteriales and Enterobacteriaceae were lower in the case group;the relative abundance of Betaproteobacteria and its subordinates Burkholderiales and Alcaligenaceae were higher in the case group.6.LEf Se analysis using pre-pregnancy BMI as a grouping variable found that the relative abundance of Actinobacteria and its subordinate Actinobacteria,Bifidobacteriales,Bifidobacteriaceae and Bifidobacterium were higher in the control group.Spearman correlation analysis found that Bifidobacterium was significantly positively correlated with rice flour products(r = 0.362,P = 0.023)and milk intake(r = 0.349,P = 0.029).Conclusions: GDM was related to changes in the composition of gut microbiota,but whether GDM occurs before changes in gut microbiota is unclear.In the future,more prospective cohort studies are needed to explore the association between GDM and gut microbiota.