You are right it's so hard to tell. My Ashleigh didn't culture PA until she was 6 (we didn't start GSH until she was 6). And she was the picture of perfect health until the PA. But, she still is very healthy...just has PA flare ups, an occasional sinus infection and digestion issues. Other than that, she is doing fantastic. We opted to do only inhaled GSH after several years of oral GSH because she was having all sorts of digestive issues and no appetite, even with the oral GSH. It was weird because it worked very well for about 2 years and then it just stopped. But, we are thankful for it because it helped her through a rough period and the inhaled does seem to help. Thanks for sharing.