I have also recently been tested for H.pylori bacteria infection by a blood test and a breath test. Both showed up negative. In the past when I have had gastritis I have taken Mastica ---2 -500 mgm capsules twice daily for 2 weeks and the pain and inflamation went away. My Doctor verified with a scope testing last year that the stomach inflammation was not seen.
So, Mastica must do more than eliminate H.pylori infections. I really think there are other bacteria that live in the Stomach areas that have not been discovered YET but cause inflammation.
I have had pain that I use to think was caused by an infected diverticula but now I don't have that part of the colon anymore but NOW an antibiotic or Mastica both cure the pain problem that I still get??? They both work for awhile but not completely---- 4 to 6 months or so???
Gas pain as far as I know is not caused by H.pylori infections or the bacteria being there.