Not necessarily. I have gastritis but no H. Pylori (was tested twice and both negative). It could be due to taking NSAIDS like aspirin, bad diet, bile reflux, and many other things. Mine was probably due to bad diet.
Gastritis is inflammation of the stomach linlng.
It can also be caused by any food that irritates your stomach as well as drugs like the pervious poster said -- NSAIDS and we are all different and respond differently.
I get gastritis fom taking a round of antibiotic. But, many people have gastritis with H pylori overgrowth.