In fact, I suspect that the vast majority of all the species of bacteria are non-pathogenic to humans.
Yeap, there are also non-pathogenic bacteria which can become pathogenic under certain circumstances. For instance if bacteria in your large intestine get into your bloodstream, it'll cause infection. Correct me if I'm wrong.
Remember that your body is a torus, and your gastrointestinal tract is the hole in that doughnut, completely outside your body. Anything that remains in the confines of that tract and does not pass through the intestinal walls into your blood is basically just as external--and just as non-pathogenic--as if it were on sitting in your hand.
I seem to recall it being described as "a tube within a tube". Only what's between the two tubes is really "in" your body.
HAY!!!! when i said the GI tract was outside the body im sure you (along with orlander) were ridiculing me for it until mad pointed out that is how med views the bodyPlease Register or Log in to view the hidden image!
Topologically, the "inner tube" is contiguous with the "outside" and they form a single space. Not me. I have always understood that.
