"While some people with candida overgrowth also suffer from gluten sensitivity, for most people, gluten is not an issue."
I wouldn't be so sure. Gluten intolerance can be subtile and not lead to the classic symptoms.
One theory, suggested by Dr. Shaw, is that the enzyme responsible for gluten and casein digestion forms complexes with yeasts compounds that result in that enzyme being unable to do its work.
Another popular theory is that a mercury burden in the intestines will prevent the production of that enzyme.
There is also the possibility that a leaky gut disrupts the enzyme, as undigested peptides will themselves impair the activity of the enzyme (vicious cycle).
That enzyme seems particularly fragile.
Undigested peptides from gluten will accumulate in fat tissues. The body eliminates it in the urine. It can takes months and even years to completely eliminate the burden of gliadomorphins (the gluten peptides).
Something interesting about celiacs even if they follow a gluten-free (and casein-free) diet, their digestion is never 100%, as the enzyme in question is also needed for many others less problematics proteins.