gamboling.co.uk

I obviously hate to sound like a pedant

But I am one so here goes: it’s “bated breath” not “baited breath”. Bated from abated which means “To reduce in amount, degree, or intensity; lessen”. So the saying means that you are lessening the number of your breaths perhaps through fear or perhaps through anticipation rather than that you have the smell of worms on your breath.

Unless of course you do have the smell of worms on your breath, but I don’t see how that is exactly relevant.