I would back it with a half inch plywood, spanning the studs every 12 to 16 inches depending on the size of your tiles.
Larger tiles will crack with any flex, smaller are more tolerant.
I like big tiles, not small.
"Don't argue with stupid people. They will just drag you down to their level, and beat you up with experience."
Patently waiting for the apocalypses to level the playing field in this physiological game of life commonly known as Civilization