Innocuous Implications of a Minimum Length in Quantum Gravity
  A modification to the time-energy uncertainty relation in quantum gravity has been interpreted as increasing the duration of fluctuations producing virtual black holes with masses greater than the Planck mass. I point out that such virtual black holes have an exponential factor arising from the action such that their contribution to proton decay is suppressed, rather than enhanced, relative to Planck-mass black holes. 
Paul H. Frampton