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Although I've heard that both wheat and oat bran should be GF I would
never use them. In a labrotory it is certainly possible to seperate the
bran from the gluten conaining part of the wheat but in the facilities
that produce bran for consumption there would almost always be
contamination. I would want to know how the processing of the wheat/oat
bran was done before I would even consider it. Corn bran is another
option but, like everything, you need to find out how and where its
processed. It may be packaged in the same machine that just finished
bagging wheat flour.

Bob Gillen