
Gut-Targeted Complex I Blockade Reveals Metformin’s Glucose-Lowering Mechanism
A Nature Metabolism study shows metformin lowers glucose by acutely inhibiting mitochondrial complex I specifically in intestinal epithelium, reducing citrulline production and boosting GDF15, thereby reprogramming the gut into a glucose sink that takes up glucose and converts it to lactate; phenformin and berberine act via the same intestine-specific Complex I mechanism, and the effect depends on short-term bolus exposure rather than chronic dosing.










