  The interrelation between inflationary cosmology and new physics beyond the
Standard Model (SM) is studied in a $U(1)_{B-L}$ extension of the SM embedded
in a (4+1)-dimensional spacetime. In the scenario we study, the inflaton arises
from the Wilson loop of the $U(1)_{B-L}$ gauge group winding an
extra-dimensional cycle. Particular attention is paid to the coupling between
the inflaton and SM particles that are confined on a brane localised in the
extra dimension. We find that the inflaton decay channels are rather restricted
in this scenario and the resulting reheating temperature is relatively low.
