Molecular Profiling Of Bacteroides And Bifidobacterium Spp. In Feces From Patients With Type2Diabetes

Backgrounds:Type2diabetes is a metabolic disease and its prevalence has increased substantially worldwide over recent decades. As a primary cause of diabetes, obesity can increase the risk of developing many others diseases such as atherosclerosis, nonalcoholic fatty liver disease, and certain cancers. Some other factors such as mental stress, infection, genetic predisposition, nutritional habits and reduction of daily physical activity may also be involved in the pathogenesis of diabetes. Recent studies have highlighted that gut microbiota may shape the host metabolic and immune network activity and ultimately contribute to the development of metabolic disorders such as type2diabetes. In this study, PCR-DGGE fingerprint and qualitative clone library were used to analyze the structural features of the predominant intestinal bacteria of patients with type2diabetes compared with healthy individuals as control, and study the influences of diabetes on the structure of intestinal bacteria.Methods:Bacterial DNAs from type2diabetes patients(n=21) and healthy volunteers (n=13)were extracted from fecal samples,and then subjected to community fingerprinting of Bacteroides and Bifidobacterium using PCR/denaturing gradient gel electrophoresis with genus-and group-specific primers,as well as sequencing excised gel bands.Results:The mean numbers of gel bands in the diabetic and control groups were6.3±1.4and5.2±2.0for Bacteroides:2.5±1.1and3.0±1.4for Bifidobacterium. The mean similarity index of Bacteroides for the diabetic group was57.0■12.7%, and76.9±5.06%in the control group, and85.9±17.4%and86.2±16.1%, respectivelyfor Bifidobacterium. The results showed that there were common bands for Bacteroides and Bifidobacterium between the two groups, but also two distinct bands for Bifidobacterium(Bifidobacterium saecularelpullorumlsubtile, and Bifidobacterium ruminantium ladolescentis) appeared only in the diabetic group.Conclusions:The results indicated that the compositional changes in Bacteroides and Bifidobacterium in the human gut microflora were associated with type2diabetes. The mean similarity index of Bacteroides as well as Bifidobacterium in the diabetic group was lower than in the control group. Comparison of control group,the sequences of Bifidobacterium saecularelpulloruml subtile and Bifidobacterium ruminantium ladolescentis are only found in diabetic group.