Gut microbiota profiling in Han Chinese with type 1 diabetes

Aims: To investigate whether microbial dysbiosis is associated with T1D in Chinese population and to explore relationships between the composition of gut microbiome and clinical data. Methods: In this study, we recruited 10 healthy and 12 T1D Han Chinese subjects between the ages of 12 to 33. Fecal samples were collected for DNA extraction and 16S rRNA sequencing, followed by analyses of the gut microbiota composition. Results: Bacterial communities differed between healthy and T1D subjects. At the phylum level, Bacteroidetes and Firmicutes are the dominant phyla in T1D patients and healthy controls, respectively. The linear discriminant analysis (LDA) effect size (LEfSe) algorithm detected 28 bacterial taxonomic clades showing statistically differences (13 increased and 15 decreased) in T1D patients. Association analyses of clinical data and microbial community abundance demonstrated that abundances of Faecalibacterium were negatively correlated with HbA1c levels (Z = −2.614, P = 0.017). The numbers of detected anti-islet cell autoantibodies were positively correlated with Bacteriodes (Z = 2.531, P = 0.011) and Bilophila (Z = 2.477, P = 0.013) abundances, while negatively correlated with abundances of Streptococcus (Z = −2.041, P = 0.041) and Ruminococcaceae (Z = −2.23, P = 0.026). Conclusions: These results suggest that Han Chinese T1D patients possess distinctly different gut microbiota, compared to healthy subjects, characterized by increased Bacteroidetes/Firmicutes ratio, negative correlation of Faecalibacterium abundance with HbA1c, and positive correlation of Bacteroides abundance with the presence of autoantibodies.