<<Disclaimer: Verify this information before applying it to your situation.>>

I had one response regarding my question on brewers yeast.
(D. Buckmann)

[There is no such thing as gluten free brewer's yeast.  However, we can use
nutritional yeast which many nutritional and health food stores (HFS) seem
to like to label as "brewer's yeast."  This of course is a misnomer.

The kind you want is made by Red Star, and they guarantee their yeast
products to be gluten free!  I believe that Red Star makes both the powdered
and a flaked form of nutritional yeast.

I found out that my HFS follows the horrible practice of repackaging and
mislabeling, but they were kind enough to show me the bag it came from and
it was Red Star Nutritional on the bag label.  BTW, I have contacted Red
Star for the gf status.]