  We derive the equation of state of symmetric nuclear matter in a relativistic
theory with $\sigma$ and $\omega$ exchange. We take a chiral version of this
model which insures all the chiral constraints. Going beyond the mean field
approach we introduce the effects of the pion loops. For the parameters of the
model, in order to fix those linked to pion exchange, we exploit the most
recent information on the short-range part of the spin-isospin interaction. For
those linked to the scalar meson exchange we make use of an analysis of lattice
results on the nucleon mass evolution with the quark mass. With these inputs we
are able reach a correct description of the saturation properties. From the
equation of state of symmetric nuclear matter we alsoderive the density
dependence of the quark condensate and of the QCD susceptibilities.
