I think you've got a few things wrong here, mate.
This thread has some misinformation in it. The way it describes the immune response to gluten is off. If you change one amino acid in a peptide it might not fit into the problem receptor anymore, meaning no more immune response.
That's an oversimplification. First of all, they have not produced an exhaustive list of peptides derived from grains that can trigger an immune response in Celiac disease. Second of all, the leading hypothesis about non-Celiac gluten intolerance is that it is an innate immune response, not an antigen-specific one, which will respond differently.
Some of the proteins in gliadin are resistant to our digestive enzymes that cut them up and that is part of the problem. If the peptides could be be chopped up by our bodies they wouldn't be able to cause the immune response.
Incorrect. It is not the gliadin itself that even causes the response, it is potentially a variety of peptide fragments (QQPFP being the most studied one) which
must be acted upon by tissue transglutaminase (TTG) first before they/it are typically rendered response-provoking. So it is the very fact that they ARE digested which renders them harmful, at least in Celiac disease. The pathology in NCGI is not well understood at this point so it would be difficult to determine how much digestion plays a role.
The enzyme in question here breaks the bond on one side of the amino acid proline. Some enzymes go to the end of a sequence and chop off single pieces, these are what your cells can absorb. Clarex instead chops the big protein up into little chunks from the middle of the chain. So you get a bunch of pieces of the chain. The chains that are implicated in celiac disease happen to contain a bunch of proline so if you cut that chain up it won't fit the receptor anymore.
The FDA does not approve drugs based on hypotheses alone. The bottom line is that no in-vivo studies have been done to evaluate whether the hypothesis behind clarex is correct, in that it actually renders beer safe. You can talk about the chemistry till the cows come home, but Celiac and NCGI are both not sufficiently understood, to the point where without in-vivo trials, any chemistry-related theorizing counts as nothing more than an untested hypothesis. This is medicine, not just chemistry.
I came to the forum to find out about brewing with clarex and there seems to be a bit of a bias against it, can anyone explain the bias?
Yes: we've tried clarex beers and they make a lot of us sick. And we are angry about it, because the people who make these clarex beers are spreading misinformation about what's really "gluten-free" in beer, resulting in establishments marketing them as GF and causing more and more people to get sick. Because gluten-free beer is such a niche, many establishments opt only to serve one brand, and much of the time it's a clarex beer that is not truly safe for all those who cannot tolerate gluten.
It's the same reason people get angry about drug side-effects in a heavily-marketed drug for some rare disease. If you took a medication and it gave you hours of severe cramping and diarrhea, wouldn't you be a little bit biased against it (especially if it was marketed as an anti-nausea drug)?
Also can anyone point me to some resources with information on home brewing with clarex and how well/not well it works?
Plenty of people will give you some anecdotal info on it working great for them. Clarex comes with instructions, if you want to use it, go ahead and use it, and stick to the regular forums because your process will be identical to barley beer brewing...because that's what you're doing. There's nothing really to discuss about it that's particularly relevant to this forum...you follow the directions and you take your chances.
Would it even matter to you if someone told you they got sick off of clarex-treated beer? It sounds like you've already made up your mind that it's the way to go, so you'll probably ignore any anecdotes that don't support your conclusion anyway. If the answers to your questions on "how well it works" won't actually change your mind about anything, there's not really a point to asking, is there?