Cereal fibre (4)
I believe the answer is:
bran
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cereal fibre</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bran that I've seen before include "Health food" , "Husks of grain sifted from the flour" , "Refuse from grain" , "Pieces of grain husks" , "Husks of cereal seeds sifted from flour" .)