  A dark energy component is responsible for the present stage of acceleration
of our universe. If no fine tuning is assumed on the dark energy potential then
it will end up dominating the universe at late times and the universe will not
stop this stage of acceleration. On the other hand, the equation of state of
dark energy seems to be smaller than -1 as suggested by the cosmological data.
We take this as an indication that dark energy does indeed interact with
another fluid (we consider fermion fields) and we determine the interaction
through the cosmological data and extrapolate it into the future. We study the
conditions under which a dark energy can dilute faster or decay into the
fermion fields. We show that it is possible to live now in an accelerating
epoch dominated by the dark energy and without introducing any fine tuning
parameters the dark energy can either dilute faster or decaying into fermions
in the future. The acceleration of the universe will then cease.
