Never heard that. The problem with gluten is the breakdown of the proteins into two specific molecules. I doubt coffee has anything in common with those amino acids.
However, coffee can become contaminated with gluten. See this webpage: http://celiacdisease.about.com/od/Gluten-Free-Beverages/f/Is-Coffee-Gluten-Free.htm
50 yrs old, IBD diagnosis in spring '01. Proctitis, gastritis, ileitis.
Pentasa (3g/day)generic Colazal ( 96 pills/day), Sulfazine (1.5 g/day), Prevacid, folic acid, vit. D (2K iu), flax seed oil (2 tsp/day), psyllium (1/2T daily), mesalamine enema as needed. Gluten free as of 5/30/11. Colonoscopy found no evidence of inflammation on 8/16/1