Distribution Characteristics Of Gut Microbiota In Pregnant Women With Gestational Diabetes And Their Offspring

Objective:To explore the difference of gut microbiota between pregnant women with gestational diabetes and normal pregnant women,and the distribution characteristics of the gut microbiota among offspring.To provide a basis for further discussion on whether gestational diabetes will have a long-term impact on diseases in children and even adults.Methods:From August 15,2018 to August 15,2019,we recruited pregnant women who regularly go to a hospital for regular obstetric examinations in Taiyuan,Shanxi Province.A1: 1 paired case-control study was conducted on pregnant women with gestational diabetes（GM group）and normal pregnant women（NM group）according to pregnancy stage,BMI value range,age ± 5 years and delivery method.Collected the basic demographic data,clinical data,excrement samples of pregnant women and clinical data and fetal excrement of their newborns.A total of 70 samples were collected,including 27 excrement samples of pregnant women with gestational diabetes,27 excrement samples of normal pregnant women,and 16 fetalexcrement samples of 8 offspring of pregnant women with gestational diabetes（GI）and 8 offspring of normal pregnant women（NI）..On the Illumina Mi Seq platform,DNA from excrement samples of pregnant women and newborns was extracted for 16 s RNA V3-V4 region amplification and sequencing.Use Epidata 3.1 to input data,and SPSS 24.0 statistical software to analyze data.Results:1.Characteristics of the clinical data of the research subjects There were no statistically significant differences on the average age,75 g OGTT test fasting blood glucose,delivery method,number of births,pre-pregnancy weight,pre-natal weight,pre-pregnancy body mass index,pre-natal body mass index,and neonatal weight between the groups of pregnant women.（P values are all greater than 0.05）.The average weight gain during pregnancy in GM group（10.44 ± 4.31kg）was less than that in NM group（14.11 ± 4.14kg）,the difference was statistically significant（t = 3.187,P = 0.002）.The blood glucose of pregnant women in GM group after 1 hour（9.63 ± 1.25）and blood glucose after 2 hours（8.70 ± 1.28）were higher than those in NM group after 1 hour（6.93± 1.53）and after 2 hours（6.52 ± 1.18）respectively（t =-6.983,-6.378,P <0.001）.There was no statistically significant differences on the average gestational age of neonates in the GI group（38.11 ± 1.31 weeks）was lessr than that in the NI group（39.19 ± 1.21 weeks）（t= 3.129,P = 0.003）.2.Analysis of gut microbiota in GM group and NM group2.1 At the phylum level,the average relative abundance composition ratio of gut microbiota in GM group and NM group was not statistically significant（P> 0.05）,and the top four bacterial groups were Firmicutes,Bacteroides,Actinobacteria and Proteobacteria,and the sum of the four components exceeds 99%（99.9% vs 99.7%）.2.2 At the genus level,There was no statistically significant difference in the average relative abundance composition ratio of intestinal flora between GM group and NM group（P> 0.05）.The top 5 gut microbiota were Bacteroides,Bifidobacterium,Faecalibacterium,Blautia and Roseburia in the GM group,were Bacteroides,Blautia,Faecalibacterium,Bifidobacterium,Roseburia in the NM group.Wilcoxon paired test showed that the relative abundance of Catenibacterium,coprococci₁,Corynebacterium₁,Hungatella,Porphyromonas,Prevotella and Ruminiclostridium₆ in GM group were higher than that in NM group（P < 0.05）.The relative abundance of Anaerostipes,prevotellaceae_ucg-001 and Libanicoccus in GM group were less than that in that in NM group,and the differences were statistically significant（P < 0.05）.2.3 By LEFSe analysis,there are 13 species with significant abundance differences between the GM group and the NM group,of which 3 species are enriched in the NM group and 10 species are enriched in the GM group.2.4 PIRUSt software was used to predict the intestinal flora of GM group and NM group.By Wilcoxon pairing test,there were statistical differences of the arelative bundance of 204 different COG genes,1 different KEGG L1 gene,1 different KEGG L2 gene,and 11 different KEGG L3 genes between the GM group and the NM group（P <0.05）.The results of KEGG L2 level suggest that the abundance of glycan biosynthesis and metabolic function of pregnant women with diabetes during pregnancy is lower than that of pregnant women with normal blood glucose levels.3.Analysis of gut microbiota in GI group and NI group3.1 At the phylum level,the top five bacterial groups were Bacteroidetes,Firmicutes,Proteobacteria,Epsilonbacteraeota and Actinobacteria in GI group,and were Firmicutes,Bacteroidetes,Proteobacteria,Actinobacteria and Epsilonbacteraeota in the NI group.The sum of the top five bacterial communities of the two groups were more than 99%.Wilcoxon paired test showed that the relative abundance of Actinobacteria in GI group was less than that in NI group（P < 0.05）.3.2 At the genus level,the top 5 of gut microbiota were Bacteroides,Romboutsia,Escherichia-Shigella,Alistipes and Prevotella in the GI group,and were Lactobacillus,Bifidobacterium,Bacteroides,Enterococcus and Romboutsia in the NI group.Wilcoxon paired test showed that the relative abundance of Coprococcus₃,Lachnospiraceae_NK4A136_group,uncultured_Bacteroidales_bacterium and Prevotella₂ in GM group were higher than that in NI group（P < 0.05）.The relative abundance of Bifidobacterium,Lactococcus,Odoribacter,Ruminococcus₂,Staphylococcus,and Subdoligranulum were less than that in NI group（P < 0.05）,and the differences were statistically significant（P < 0.05）.3.3 By LEFSe analysis,there were 37 species with significant abundance difference between GI group and NI group,among which 18 species were enriched in GI group and19 species in NI group.3.4 PIRUSt software was used to predict the function of gut micribiota in GI group and NI group.Wilcoxon pairing test showed that there were statistical differences of the abundance of 172 different COG genes,1 different KEGG L1 gene,3 different KEGG L2 genes and 19 different KEGG L3 genes between the GI group and the NI group（P < 0.05）.At KEGG L1 level,the metabolic function relative abundance of GI group was lower than that of NI group.At KEGG L2 level,the relative abundance of endocrine system,biodegradation and metabolism as well as amino acid metabolism in GI group was lower than that in NI group.4.Wilcoxon pairing test showed that there were no statistically significant differences between GM group and NM group and between GI group and NI group in the α diversity indexes: Chao 1 index,goods coverage index,observed species index,PD whole index,Shannon index and Simpson index（P > 0.05）.By ADONIS,there were no statistically significant differences between GM group and NM group and between GI group and NI group in β diversity index: Weighed Unifrac distance and Unweighed Unifrac distance（P > 0.05）.Conclusions:1.The distribution of the gut microbiota genus of pregnant women with gestational diabetes and their offspring is different from that of pregnant women with normal blood glucose and their offspring.Ten kinds of bacteria were enriched in pregnant women with gestational diabetes,which can be used as biomarkers for gut micribiota of pregnant women with gestational diabetes.Eighteen kinds of bacteria were enriched in the offspring of pregnant women with gestational sugar,which can be used as biomarkers of gut micribiota in the offspring of pregnant women with gestational diabetes.2.Prediction of microbial gene function suggested that pregnant women with gestational diabetes mellitus and their offspring had changes in microbiota function.Glycan biosynthesis and metabolic function abundance of pregnant women with gestational diabetes mellitus were lower than that of pregnant women with normal blood glucose levels.The offspring of pregnant women with gestational glucose had lower levels of metabolism,endocrine system,biodegradation and metabolism and amino acid metabolism than those of pregnant women with normal blood glucose.