Hi Cocalab; Welcome to the forum. I hope you enjoy yourself here. As you'll discover there are many diverse topics here, all dealing with something. I copied this from Wikipedia in response to your shit filled lake:
It is estimated that 500 to 100,000
species of bacteria live in the human body
[2]. Bacterial cells are much smaller than human
cells, and there are about ten times as many bacteria as human cells in the body (1000 trillion or 1 quadrillion (1015) versus 100 trillion (1014)).
[2] Though normal flora are found on all surfaces exposed to the environment (on the skin and eyes, in the mouth, nose,
small intestine, and
colon), the vast majority of bacteria live in the
large intestine Best to you, Pat