[en] The self-energy of the K^- meson in nuclear matter is calculated in a self-consistent microscopic approach, using a KbarN interaction obtained from the lowest-order meson-baryon chiral Lagrangian. The effective KbarN interaction in the medium is derived by solving the coupled-channel Bethe-Salpeter equation including Pauli blocking on the nucleons, mean-field binding potentials for the baryons and the self-energy of the π and Kbar mesons. The incorporation of the self-consistent Kbar self-energy in the description, in addition to the Pauli blocking effects, yields a weaker attractive in-medium KbarN interaction and a Λ(1405) which dissolves faster with increasing matter density, as a result of the Kbar spectral function being spread out over a wide range of energies. These effects are further magnified when the intermediate pions are dressed