The 3M roles of the gut microbiome in pharmacotherapy for diabetes: mediator, modifier, and marker.

The rising global prevalence of type 2 diabetes mellitus (T2DM) presents major challenges to healthcare systems; thus, more effective treatment strategies are urgently needed. In this context, the growing recognition of the gut microbiome's role in T2DM pharmacotherapy has shifted attention toward integrating microbiome-derived mechanisms to optimize drug response. This review proposes a structured '3M' framework that classifies the gut microbiome's roles in T2DM pharmacotherapy into three translational categories: mediator of drug action, modifier of therapeutic response, and marker for predicting efficacy or intolerance, based on recent clinical and mechanistic insights. Together, these insights support a translational framework that may guide the integration of microbiome-informed strategies into future T2DM pharmacotherapy.