Used to have gluten intolerance before I developed ME/CFS. Eating a gluten-containing meal would reliably precipitate dark gloomy depression within 1 hour (and this depression would last for around 6 to 8 hours before wearing off). Such brief episodes of depression are a classic symptom of gluten intolerance.
I had this gluten intolerance all my life. However, since developing ME/CFS, I observed that this gluten intolerance disappeared, which is interesting.
But an individual who caught the same virus as me, the coxsackievirus B4 virus that likely triggered my ME/CFS, they actually developed gluten intolerance after catching the virus (in that eating gluten causes digestive upset).
So it seems that catching a viral infection can change the status of your gluten intolerance: either triggering gluten intolerance, or eliminating an existing gluten intolerance.
Since gluten intolerance is immune system mediated, this is perhaps not surprising that a chronic viral infection like coxsackievirus B can alter gluten intolerance status.
Incidentally, according to
fascinating research by Dr Alessio Fasano, the difference between gluten intolerance and Crohn's disease is that former arises when gluten activates the innate immune response (but not the adaptive immune response) in the intestinal lining. Whereas in Crohn's, both the innate and adaptive immune response are switched on by the presence of gluten, and it is the adaptive immune response that causes all the bowel damage in Crohn's. But this bowel damage does not occur in gluten intolerance.