The toilet is the cleanest place in the house
A lot of people say it, and I've seen a couple of tests demonstrate it, but I'm always amazed when people are suprised by it.
I've always assumed that the toilet would be cleaner than anything else precisely because it's dirtier than anything else; surely anything you poop in is going to be cleaned more regularly and more thoroughly than anything else...
Since nothing else gets defecated on, it surely isn't seen as dirtier than a toilet. Therefore, while one might bleach a toilet, one might only use soap and water on everything else - which I'm guessing isn't as powerful as bleach. So at any given moment there should be fewer bacteria in the toilet.