That's fascinating because I had a similar experience with nitric oxide. Oral nitroglycerin, which is absorbed in the mouth didn't do much worsening, but Isosorbiddibnitrate which is swallowed and slow-release cause horrible crashes for several days. Both release nitric oxide in the body, but nitroglycerin never reaches the gut.One experiment at least for some chemicals is to try sublingual absorption. For me, cumin worked just as well sublingually (with the residue spat and rinsed out) as when swallowed, so I took that as evidence that the digestive system wasn't involved.
That's one reason why I also assumed the problem is gut-related and might very well have to do with the microbiome.
But I have never found a way to derive a benefit from that hypothesis as all probiotics and antibiotics didn't do much. Maybe the bacteria that do it are ubiquitous, so it's impossible to get rid of them. I thought maybe fruit is bad, especially when mixed with other problematic foods, not because of something bad in fruit, but because it feeds the bacteria which then turn more of the other foods into harmful products.
That would explain why fruit alone has a very different effect than fruit with other foods, even if other foods are in the next meal.
I have experienced the following.
Fruit --> Lentils --> BAD
Fruit --> Mushrooms --> BAD
Fruit + Whole grains --> BAD
All three are high choline foods.
I will check this in detail in the coming weeks. Will try fruit and then pasta and Zucchini or cheese and white bread, which is low in choline.
Thank you so much for this interesting suggestion. This is so helpful for getting new ideas.