Mine is low carb, but also no wheat. Even when I do small (or even sometimes medium) amounts of rice, enough to absolutely not be in ketosis, I am still better than I was when eating bread or bread-containing/adjacent things (breading, pasta, sandwiches, et c). We know I'm not celiac. Perhaps it's some weird allergy; in addition to acid reflux eating such things also used to cause me ENT issues like coughing/congestion which have gone away entirely since I stopped. None of the traditional "allergic reaction" symptoms, though.

Who knows?

All I know is that it's different for everyone and for lots and lots of people, eating totally normal things is what causes or contributes to lots of bad symptoms misattributed to some disease or disorder. More often than not it's not you, it's the utter garbage food that our society has standardized upon. Just because it's common to eat a sandwich, or pasta, or a bowl of cereal or granola, or a bagel doesn't mean that human evolution has caught up with it yet.