Interesting article - these sentences jumped out :
"Our biochemical measures showed nothing at all - but that could mean that we were just measuring "the wrong things". The immune and inflammation systems are, after all, among the most complex aspects of the human body, and we have much yet left to understand.
On top of that, we are only just scratching the surface about understanding our relationship with our gut bacteria. There is the possibility that some people have gut bacteria that create symptoms when fed gluten-containing foods - something that might not have shown up in the markers we tested."
'Trust Me, I'm A Doctor ' is on tonight - BBC Two at 20:00 BST