In this study, LEfSe multilevel species hierarchical tree directly reflects the differences of gut microbiota between control and T1DM rats at the Phylum-to-Family level, the result showed that the gut microbiome of T1DM rats changed significantly. The abundance of pathogenic bacteria associated with infection and inflammation in T1DM rats was up-regulated such as Ruminococcaceae, Shigella, Enterococcus, Streptococcus, Rothia and Alistipes, while the abundance of beneficial bacteria and bacteria producing SCFAs were reduced such as Lactobacillus, Faecalitalea, Butyricicoccus and Allobaculum.

The incidence of type 1 diabetes mellitus (T1DM) is increasing year by year, gut microbiota is considered to be closely related to the occurrence and development of T1DM in recent years. In this study, Sprague Dawley (SD) rats were intraperitoneally injected with 75mg/kg streptozotocin to establish T1DM model, fecal samples were collected and DNA were extracted, 16S rRNA microbial gene clone library were constructed, and lastly high-throughput sequencing and bioinformatics analysis were performed. The results showed that the abundances of pathogenic bacteria such as Ruminococcaceae, Shigella, Enterococcus, Streptococcus, Rothia and Alistipes associated with infection and inflammation in T1DM rats were up-regulated, while the abundances of beneficial bacteria such as Lactobacillus, Faecalitalea, Butyricicoccus and Allobaculum were reduced. Among them, Butyricicoccus and Allobaculum protect intestinal barrier function by producing short-chain fatty acids. This study suggests that intestinal inflammation and reduction of short chain fatty acids (SCFAs) caused by the imbalance of gut microbiota are crucial to the pathogenesis of T1DM.