  Nuclei make up the majority of the visible matter in the Universe; obtaining
a first principles description of the nuclear properties and interactions
between nuclei directly from the underlying theory of the strong interaction,
Quantum Chromodynamics (QCD), is one of the main goals of the nuclear physics
community. Although the theory was established nearly fifty years ago, the
complexities of QCD at low energies precludes analytical solutions of the
simplest hadronic systems, let alone the features of the nuclear forces. In
this thesis we follow the lattice QCD approach, according to which QCD is
solved non-perturbatively in a discretized space-time via large-scale numerical
calculations. Specifically, the interactions between two octet baryons, with
strangeness ranging from 0 to -4, are studied at low energies with
larger-than-physical quark masses, and the low-energy coefficients in pionless
effective field thepry relevant for two-baryon interactions, including those
responsible for SU(3) flavor-symmetry breaking, are constrained.
