To explore the causal association between gut microbiota and type 2 diabetes mellitus (T2DM) using two-sample Mendelian randomization.

The data of single nucleotide polymorphisms (SNP) of gut microbiota as an exposure factor and type 2 diabetes mellitus as an outcome variable were obtained from the public genome-wide association study database. MR-Egger, weighted median method, inverse variance weighted method (IVW), simple model, and weighted model were used for MR Analysis. The MR-Egger method and IVW method were used for heterogeneity analysis. MR-Egger intercept was used to test the pleiotropy of the data, and the leave-one-out method was used for sensitivity analysis to evaluate the robustness of the results.

A total of 7 gut microbiota were found to be associated with type 2 diabetes in East Asians, and the risk bacteria were Eubacteriumnodatumgroup, Ruminococcaceae UCG010, Lachnospiraceae NK4A136 group, Victivall, and protect bacteria were Enterorhabdus, Erysipelatoclostridium, Romboutsia. There were a total of four kinds of intestinal flora in the European population associated with type 2 diabetes, dangerous bacteria were Howardella, Eubacteriumruminantiumgroup, Eubacteriumventriosumgroup, and protect bacteria were FamilyXIIIAD3011group.

Specific gut microbiota may have causal effects on the risk of type 2 diabetes.