That quote is from How much of you is really you? at Gluten Free For Good.
We talk a lot about whether a specific food hurts or helps us, but there is a lot more to your intestinal health that whether you have eaten some wheat accidentally.
Melissa has written a very educational piece about bacteria, medical ecology and tending our microbial garden. I have followed many of these same tips over the past few months and things have improved a lot for me.
(Picture (and another article about bacteria ) from Crasstalk.)