maybe the rennet? @sheseala
@sheseala @Armchaircouch
That or the bacteria would be my guess.
The higher the quality, the longer it's been left to mature (in most cases, anyway) which means higher levels of the bacteria which give it much of its character. The bacteria aren't usually harmful but if your body is a bit intolerant, that might be why.
@stueytheround @Armchaircouch my searching just now lead me to learn there is something called abdominal migraine. I don't have anywhere near those issues that but omg why is that a thing.