  We discuss the possible influence of fundamental QCD properties such as
spontaneous chiral symmetry breaking and nucleon substructure on nuclear matter
properties. We propose a chiral version of the relativistic $\sigma-\omega$
model in which the attractive background scalar field is associated with the
chiral invariant field governing the radial fluctuations of the quark
condensate. Nuclear matter stability is ensured once the scalar response of the
nucleon depending on the quark confinement mechanism is properly incorporated.
The needed parameters are estimated from lattice results and a satisfactory
description of bulk properties follows, the only really free parameter being
the $\omega NN$ coupling constant. Pion loops can be also incorporated to
obtain in a consistent way the finite density chiral susceptibilities. A good
description of the asymmetry energy is obtained once the full rho meson
exchange and Fock terms are included.
