Correlation Analysis Between Type 2 Diabetes And Intestinal Core Flora Based On Clinical Cases

Recent evidence suggests the importance of the gut microbiota as an environmental factor,and an altered gut microbiota has been linked to metabolic diseases including the development of Type 2 diabetes(T2DM).To better understand the composition and richness of the gut microbiota of healthy individuals and T2DM patients,to reduce the impact of other factors and filter the biomarkers to identify the disease,the study comprised 133 human subjects including 78 healthy individuals and 55 T2DM patients.Feces samples were collected and DNA were extracted from stool sample.The PCR products were purified,sequenced using an Illumina HiSeq 2500 system(Illumina,USA)and then conserved V3+V4 region of the 16S rRNA gene was amplified by PCR from the isolated DNA.The Illumina sequencing strategy for the V3+V4 region was paired-end and dual-end sequencing.The generated sequences were analyzed using QIIIME software for identification and annotation of unique target sequences(tags)and operational taxonomic units(OTUs).The rarefaction curve was drawn to assess whether the amount of sequencing was sufficient to cover all groups,and to reflect the richness of species.The Alpha diversity was used as the analysis of species diversity in a single sample,including Chao1,Shannon and Simpson indices.Beta diversity was calculated using weighted and unweighted UniFrac distances.Linear Discriminant Analysis(LDA)was employed to estimate the effect size of each differentially abundant feature using the default effect size threshold of 2(log 10)and select corrected biomarkers from those LDA results.DNA was successfully extracted,PCR amplified and amplicons sequenced for 133 samples,yielding a total of 25,375,243 paired-endreads and 17,371,759 high-quality reads after quality control.The maximum reads are 193,482,the minimum reads were 60,381.The most dominant bacterial phylum among all participants,both healthy and T2DM patients,were the Firmicutes?Bacteroidetes?proteoK_Bacteria?Actinok_Bacteria.The bacterial class were Bacteroidales?Clostridiales?EnteroK_Bacteriales?Selenomonadales?Lactobacillales?BifidoK Bacteriales and Burkholderiales?bacterial order were Bacteroidales?Clostridiales?EnteroK_Bacteriales?Selenomonadales?Lactobacillales?BifidoK_Bacteriales and Burkholderiales;bacterial family are Bacteroidaceae?Lachnospiraceae?Ruminococcaceae?Prevotellaceae?EnteroK_Bacteriaceae?Veillonellaceae?Lactobacillaceae?BifidoK Bacteriaceae?Porphyromonadaceae?EuK_Bacteriaceae and Rikenellaceae,and bacterial genus were Lachnospiracea incertae sedis?Faecalibacterium?Escherichia/Shigella?Clostridium_X1Va?Ruminococcus?Gemmiger?Klebsiella?Megamonas?Blautia?Eubacterium?Clostridium_??Megasphaera?Roseburia?Dialister and Oscillibacter.Significant differences in intestinal microbiota were found between the healthy individuals and T2DM patients,for example,Bacteroides,Prevotella,Faecalibacterium,Lachnospiacea incertae sedis,Clostridium_X1Va were higher in healthy individuals,and Escherichia/Shigella,Bifidobacterium,Ruminococcus,Gemmiger,Megasphaera,Lactobacillus were expressed higher in T2DM group.Alpha-diversity indices were not significantly between two group,while Beta-diversity by all measures showed differences between two group.In statistical analysis and biomarker selection,Bifidobacterium?BifidoK_Bacteriales?BifidoK_Bacteriales?Laceyella?Thermoactinomycetaceae?Bacillales?Lactobacillales?Lactobacillales?Cupriavidus?Pelagicoccus?Puniceicoccales?Puniceicoccaceae,?Bacteroidetes?Bacteroidaceae?Bacteroidales?Vagococcus?Clostridium_X1Va?Lachnospiracea incertae sedis?Rhizobiaceae?Roseburia?Rhizobium?Clostridium_?? and Megamonas were all marked as biomarker as distinguishment.Besides,after correction,OTU1001?OTU1104?OTU13?OTU140?OTU2488?OTU25?OTU381?OTU415?OTU4585?OTU541?OTU736?OTU9 were the neat results that come from only connected to blood glucose.The other results show Bifidobacterium was an outstanding remark that had higher expression in T2DM group which different from previously reported.Our findings shed new light on the gut microbiome in relation to T2DM,exhibiting the core gut microbiome was significantly different from the healthy individuals.And the differentiated microbiota data and the potential biomarkers may be used for T2DM diagnosis and prevention.