at the same time how do we reconcile that a majority of the world harbors h. pylori and doesn't suffer from ulcers? From what I understand, there will always be

at the same time how do we reconcile that a majority of the world harbors h. pylori and doesn't suffer from ulcers? From what I understand, there will always be "good" and "bad" bacteria inside us, the important part is the balance between the two. If antibiotics do knock out an h.pylori "infection" that is causing ulcers that's great, but what about the other bacteria that the antibiotics might be affecting? Will that offset the scales in another undesirable way?