AMP-activated protein kinase (AMPK) mediates the glucose-lowering effect of the antidiabetic agent metformin, but the sites of action remain unclear. In the March issue of Nature Communications, Zhang and colleagues reported that intestinal epithelium-specific AMPKα1 knockout mice fail to respond to metformin and exhibit disruption in metabolic homeostasis secondary to changes in the gut microbiome. This highlights a therapeutic potential of targeting intestinal AMPK for diabetes.