Really short version: I worked on correcting the extreme acidity my genetic disorder promotes and I consumed a combo of high brine sea salt, coconut oil, glyconutrients and organic yogurt. I did a lot more than that but that is a good place to start, assuming you are hoping to act on the info. Organic yogurt has more varieties of flora than other yogurts and coconut oil does good things for gut flora.

By "extreme acidity" do you mean in your gastrointestinal system or elsewhere? (I've heard people talk about blood-level acidity before.) Was there a test that let you track/monitor acidity as you made changes?

I have a form of cystic fibrosis. It is well established that it makes all the tissues generally more acid but it is not really treated under conventional medicine.

I know of people who tested urine or saliva to monitor ph levels but I did not. I monitored it symptomatically. I could feel when my gut was more acid and it eventually became clear that lung inflammation was directly correlated.

As for blood ph, the body works really hard to keep that within a narrow range. Otherwise, you die. And pretty quickly. The body will strip your bones of calcium to try to keep blood ph stable. If you have an acidity issue, it is best to assume it is systemic rather than localized.