I remember reading a few articles that our stomach contains our second brain. Therefore there is bio feedback mechanism between our stomach and mind, and I agree with Jan, it could be no more than a placebo at play when dieteray changes help eleviate intollerances. I certainly dont think it eliminates them for good. I believe, eating even unhealthy foods, within moderation can even help strengthen our bodies immune system and ability to heal, just like our body becomes more resistant to foreign bodies such as the common cold etc. Ultimately, our bodies and intollerances develop as our physiology changes as long as we have a healthy mind, everything else will follow.