High-fiber cereal (7)
'high-fiber cereal' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bran that I've seen before include "Milled grain husks" , "Coarse meal for horses" , "Separated grain husks" , "Food from the husks of cereal grains" , "Type of roughage" .)