Name one strain of the bacteria that usually lives harmlessly in the digestive tracts of humans.

Eschecharia coli "E.Coli" is Bacterian strain which can survive within Digestive System of Human Body

It may also Cause Infection in your <Human> Gutt

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.