  Dark matter candidates and proton decay in a class of models based on the
AdS/CFT correspondence are discussed. We show that the present bound on the
proton decay lifetime is inconsistent with ${\cal N} = 1$ SUSY, and strongly
constrains ${\cal N} = 0$ non-SUSY, low scale trinification type unification of
orbifolded AdS$\otimes S^5$ models.
