It doesn't break down that's why it's noncaloric. Nothing is metabolized, it just passes through. Are you afraid of water, salt and toothpaste too? They all contain chlorine.
Ah, okay, I was wondering the science on this -- when the commercials came out, "Tastes like sugar because it's made from sugar", I was curious to know if they'd been able to do something like draw the *sweet* from sugar cane and leave the fibrous plant matter behind.
Please post a link to your source on sucralose not breaking down at all in the human body. Please tell us about it.