LONDON,(Reuters) - Since he ditched Marlboro Lights five years ago, Daniel’s fix is fruit-flavored nicotine gum that comes in neat, pop-out strips. He gets through 12 to 15 pieces a day and says he has “packets of the stuff” stashed all over. But he doesn’t see himself as a nicotine addict. A man participates in a test in the "smoking laboratory" at Bristol University in England May 1, 2015. REUTE