Causal relationship between gut microbiota and type 2 diabetes: a two-sample Mendelian randomization study.

BACKGROUND

Studies showed that development of gut microbial dysbiosis has a close association with type 2 diabetes (T2D). It is not yet clear if there is a causal relationship between gut microbiota and T2D.

METHODS

The data collected from the published genome-wide association studies (GWASs) on gut microbiota and T2D were analyzed. Two-sample Mendelian randomization (MR) analyses were performed to identify causal relationship between bacterial taxa and T2D. Significant bacterial taxa were further analyzed. To confirm the findings' robustness, we performed sensitivity, heterogeneity, and pleiotropy analyses. A reverse MR analysis was also performed to check for potential reverse causation.

RESULTS

By combining the findings of all the MR steps, we identified six causal bacterial taxa, namely, and . The risk of T2D might be positively associated with a high relative abundance of and but negatively associated with and The results of MR analyses revealed that there were causal relationships between the six different genera and T2D. And the reverse MR analysis did not reveal any evidence of a reverse causality.

CONCLUSION

This study implied that and might have anti-protective effect on T2D, whereas , and genera might have protective effect on T2D. Our study revealed that there was a causal relationship between specific gut microbiota genera and T2D.