A theory of everything like matter action is a simple set of particles and exchanges and so a TOE must first define the matter and action of its particles. The matter-action universe has only one fundamental particle, aether, but aether manifests as four really illustrative matter-action particles: electrons, photons, quarks, and neutrinos. Atoms make up the matter of the universe as electrons, protons, and neutrons while photons and neutrinos fill the space in between matter accretions.
Quark pairs are what make up protons and neutrons and so the electrons and quarks are what make up the atomic matter of the universe. Thus the particles of electrons and quarks make up matter with the particles of photons and neutrinos make up the action or forces that bond electrons and quarks into matter.