Anything with sugar in it can make the keys stick, but you can usually clean it up. Shut down the computer, unplug the keyboard, thoroughly rinse it out in the sink, let it dry overnight. If any of the keys start sticking, just grab some rubbing alcohol and a some cotton swabs.
If this is a cheapo keyboard, and the keys are sticking really badly, I'd probably just replace the keyboard. But if its an expensive keyboard, I'd clean it up good.