The Enzyme Nobody Is Talking About in Chronic Gut Dysfunction — section

Electron Transport Chain — Complex I and II. SIRT3 deacetylates and activates subunits of Complex I (NDUFA9) and Complex II (SDHA — succinate dehydrogenase). These are the entry points for electrons into the chain. When SIRT3 is low, Complex I and II activity drops. Electron flow slows. ATP output falls. But it gets worse — stalled electrons leak from the chain and react with oxygen to form superoxide. So low SIRT3 doesn’t just mean less energy. It means more oxidative damage to the very organelle that’s already failing.