First time i got gout i had no idea what it was. Didn't treat it immediately and after three days couldn't put my right foot on the ground. Still have the image of being helped down a slope to a car with each arm over the shoulder of each of two people, one each side. i was on holiday up north a bit from Sydney, and was put on a bus back to Sydney, my choice.
There i saw my doc and was given a gout tablet which say three or four, cleared it up over about 4 days, by memory.
It didn't take long for me to learn that seafood, not a little, but quite a lot at one time caused gout in me. Fish and chips, ok, no swear, but a good fish lunch would bring it on.
So agree by experience and personal experimentation (i've done that with about everything) some things are caused by some food intolerance.
As a kid i was diagnosed with allergies, and had regular shots. First the needles up each forearm, 10 each arm, 20 at a time. Then as science progressed, scratches and a solution from a dropper replaced needles. House dust (actually the mites in it), chocolate, wool whatever. Trouble is the allergies kept changing. In about '62 i was living at uni (UBC), dad had our home carpeted with cotton because i had tested allergic to wool. After that i could only go home for say three days before hay fever, itchy nose was too much. On being tested again i showed an allergy to cotton.
In about 1969, by that time in Sydney, i was still taking antihistamines for allergies, but was getting fed up with them drying the nose out and getting a bit drowsy from them, but then after a few hours being back where i started. So just stopped taking them. Oh, except on telling the story to a golfing buddy drug salesmen some time later he said he could give my free samples out of the boot of his car so i did that for fun for a time for the fun of it. Just to add to the effect of a few beers after golf.
Anyway i didn't have any more troubles with allergies after that, and haven't been tested since. No doubt in my mind if i was tested i would be positive to many things, but for years i was there and never going back to it. I have a good general attitude to food, i love most all of it. And don't eat much of any sugar etc.
Back to the gout. For years now it has only come back occasionally. Alcohol, research says, can bring it on. Oddly, I've found it's come back when i have gone off drinking. Not every time. And yes, occasionally it has come after a very heavy few days. But, i have not been able to tie it's recurrence to anything really except a lot of different seafood in a lunch or two over a couple of days (that happened in Vietnam where was always treated to seafood lunches.) Very seldom get any gout anymore. And don't have heavy seafood lunches. When i visit Vietnam next will make sure i have tablets handy, in case, after lunches.
In a number of searches, yes changed wording, just now i haven't found any evidence at all that food intolerance can cause athlete's foot or any other fungal disease. i'm not saying that particular info in your link is wrong, Just saying i couldn't corroborate it with any searches.
Finally, though being well aware that some doctors are in the pockets of some drug companies i don't share your overly, i think, cynical
"I've had gout for years and have done a deep dive into the food intolerances space. Of course, doctors would rather prescribe shit, it what's they do. Check it out, what do you have to lose?"
and unfair, i think, attitude about doctors in general. I'm not at all surprised to hear it coming from you.
Oh, and would add no doubt those involved in your link would likely have an agenda interest too. Like tarot card readers.