Hi there......finally, there is someone a bit like our son. He is 13 and was diagnosed early this year. Knowing what we know now, it is clear that he has been PI pretty much from birth (but we did not know that at the time) and he had fairly typical PI stools and a lot of pain when he was little. We ended up giving him lots of probiotics and eventually were told he could not tolerate gluten, so stopped that. When he was finally diagnosed this year (because of lung issues) as a DDF508 like you, the CF team simply did not believe us that he has NO tummy aches, no frequent or smelly or oily stools etc. They tested his stools and found him to be PI. They tested nothing else. They then told us he has to take enzymes which he does now, but it makes no difference that we could name....we just hope he does digest the fat-soluble vitamins better, but we have no evidence of that yet....and like you he has not had problems with his weight (he was always slight, but did thrive), until the lung problems started. We consulted a naturalist doctor and he suggested Lukas is somehow managing to use a different enzyme for digestion.....a bit like yours is saying about the bacteria. I only know of one other patient a little similar, but you are the first I heard of sounding almost the same! So good to read your post.