Regardless of how much Lysol you want to spray around the house, the fact is that human beings need certain kinds of bacteria. While some bacteria is bad, and eats our face and makes us sick, there's other bacteria that helps us digest and swims around inside us in a symbiotic (partnered) relationship. Without these bacteria, we're actually on the road to ruin. It's a weird situation, but you've gotten along with it so far.
It is possible for this bacteria within us to die off, raising all sorts of medical issues. It doesn't just happen, but when it does, we start feeling really awful.
One way to fix this problem is the unbelievably disgusting fecal transplant, wherein bacteria located within feces of a donor is placed in your lower colon to have a grand old time and start a new life in your bowels. Granted, if you've gotten into this situation, you're pretty much ready for anything.