Metformin’s Hidden Target: The Gut Takes Center Stage

New Northwestern University research in mice shows metformin mainly acts in the intestine, lowering blood sugar by reducing mitochondrial activity in gut cells and prompting them to burn more glucose, challenging the idea that the liver is the primary target. Published in Nature Metabolism, the study links berberine to a similar gut pathway and uses engineered mice to show that blocking mitochondrial complex I in the gut is central to metformin’s effect, with implications for gut-targeted diabetes therapies.