Can negative foodreactions/foodintolerances be a good thing?

I was wondering when eating more and different foods and you start to have some questionable symptoms from something you ate for years,if it can be a good thing?

For years I’ve used Himalayan Salt and since introducing seasalt and pickling salt a couple of months ago,I now all of a sudden seem to experience some questionable things when eating Himalayan Salt.
The years I’ve used it without these problems,while eating buckets of it, I was very lowcarb Paleo,so basically starvation mode.

My theory is, now that it’s getting nutrients from other foods,it feels safe to ‘cherrypick&revolt against’ as in what foods it feels are more optimal over others?…basically that it always put up with the Himalayan Salt in order to stay alive bc it was one of the few sources to get minerals from?

So can foodintolerances sometimes be a good sign?