Focusing just on that last item, a thought occurred to me: you've given examples of doctors who claim that "leaky gut syndrome" is genuine, and advocate certain therapies based on that premise, but the question that remains unanswered is whether even these doctors use said therapy. By which I mean actually prescribe them to paying patients and place themselves at risk of a malpractice lawsuit if they screw up. Types like Galland, Mein and Stoll can write (non-peer-reviewed) articles, books and web pages, and provide "health coaching" by phone all the life-long day, but do any of them genuinely put their altie claims into practice in situations where their conduct as medical professionals (ostensibly) could come under scrutiny from a review board or a court of law?