What interactions do bacteria and humans have?

Answer 1

For the huge numbers of bacteria that live symbiotically with us, in our gut and elsewhere, it is mutually beneficial. The human body creates a lovely, safe environment for the bacteria, and they provide us with certain substances (like vitamin K) that we cannot produce on our own.

Pathogenic bacteria are another matter altogether, but I don't think you are asking about those.

Answer 2

Bacteria are of immense importance for very existence of human race. Vise verse is also true for many species of bacteria. You can not survive without bacteria in your colon. List of uses of bacteria is too long to mention. Even disease causing bacteria are also probably useful for LONG TERM existence of human being.

Answer 3

Escherichia coli is the most common bacterium found in the intestines of humans which helps in the production of Vitamin B.