A recent
new concept derived from synbiotics is known as metabio-
tics, which refers to the
“
structural components of probiotic
microorganisms and/or formulation of and/or signaling mole-
cules with a determined (known) chemical structure that can
optimize host-speci
fi
c physiological functions and regulate
metabolic and/or behavior reactions connected with the
activity of host indigenous microbiota
”