Yes there is. Mine was diagnosed 15 years ago, and everytime i drink barley based “gluten free” beer i get symptoms, like big underskin pimples on my face, not cool! And loose stomach and gas. And all of those are under 20 ppm, labeled “gluten free” but think about it.
The mash is from barley, rye and maybe even wheat, i seriously don’t believe that some magic chemical reaction would take the glutein away completely, it might break it to so little pieces that it is impossible to find.
If you have celiac disease i advise to drink only gluten free beer made from gluten free ingredients…