DENVER — Smashburger customers may soon order a hamburger on a gluten-free bun. The fast-casual chain has announced a partnership with Udi’s Gluten Free, a business unit of Boulder Brands, Inc., to offer a gluten-free bun option at locations in the United States.

“Practicing a gluten-free diet is an emerging consumer trend, and Udi’s is the clear quality leader in the gluten-free category,” said Tom Ryan, founder and chief concept officer of Smashburger. “The addition of Udi’s gluten-free buns fits in well with our strategy of marketing to consumers looking for healthy menu options.”

Smashburger said it also has reformulated its seasoning for burgers and grilled chicken to be gluten-free. Though some toppings contain gluten, and cross-contamination may occur in the kitchen, the chain said customers may now order a completely gluten-free entree option.

Since 2010, gluten-free claims on restaurant menus have grown by 200%, according to Chicago-based market research firm Mintel. Boulder Brands said last year it has been working with other national chains to expand the availability of gluten-free offerings in food service.