i just came across this fact while i was reading a book. it says that whenever we poo and then flushes the toilet, the water flushing down the bowl creates a very powerful aerosol of droplets that scatter quite a distance and carries faecal bacteria (poo bacteria). those droplets travel up to 6 meter from the toilet, which means the when you brush your teeth with that toothbrush of yours,.. i am sure its less than 6 meter from the toilet. but when you close the lid, obviously, the poo bacteria travel far less but this means that the bacteria is all over the toilet seat and the lid.
marcikular..what a disturbing filthy fact.