Amadeus Schmidt wrote:

>This "undigestable" bran, also known as fiber,
>is an ideal supply for our gut symbionts.

Are you recommending bran? What about the phytic acid in it? Phytic acid is
found in the bran. It strongly binds to minerals like calcium, iron, zinc
and magnesium to form insoluble salts, phytates, which precipitate from the
body. I have 60 references on this. This article by Staffan Lindeberg uses
29 of them as footnotes:

  http://maelstrom.stjohns.edu/CGI/wa.exe?A2=ind9706&L=paleodiet&O=T&P=850

Don.