  We discuss quantum gravitational loop effects to observable quantities such
as curvature power spectrum and primordial non-Gaussianity of cosmic microwave
background (CMB) radiation. We first review the previously shown case where one
gets a time dependence for zeta-zeta correlator due to loop corrections. Then
we investigate the effect of loop corrections to primordial non-Gaussianity of
CMB. We conclude that, even with a single scalar inflaton, one might get a huge
value for non-Gaussianity which would exceed the observed value by at least 30
orders of magnitude. Finally we discuss the consequences of this result for
scalar driven inflationary models.
