How is the bacteria saprobic bacteria helps?

One way that they help is by helping us digest our food. We have what are called intestinal flora, a group of many different bacteria in our digestive system that help us by breaking down food...

Bacteria helps us break down food. I believe they also help to break down dead organism and release the oxygen as well as nutrients of the organism back to the earth.

There are no bacteria on other bacteria. Some bacteria do attack other bacteria by piercing their cell wall and injecting proteins. Viruses can attack bacteria. They are called bacteriophages.

because they take over other bad bacterias and they can be good or bad

It help us in many different ways like they digest our food they give us witamin K they find the bad bacteria