Holographic flavor in the gauge/gravity duality

In this paper we review some results on the generalization of the gauge/gravity duality to include fundamental matter by means of probe branes. We compute the meson spectrum of maximally supersymmetric gauge theories in several dimensions, both in the Coulomb and Higgs branch. We also study the addition of flavor and compute the meson spectrum for non-commutative theories. Additionally, we present a thorough search of supersymmetric embeddings of probe branes in the Klebanov-Witten model.