I'm sure I read somewhere that we are made of bacteria, basically every single living cell in our bodies is biologically a type of bacteria. The type of bacteria that we are made off is, according to modern theories of evolution anyway, exactly the same stuff that made the very first living creature that swam this earth, or evolved from a pile of dinosaur shite, or even farther back than that back ferments of the froth of genesis. I think that's right anyway. You can better check The Web of Life (Capra). In any case the fact that we are made of bacteria is the least mind boggling fact about our existence.