A lot of truth in those words. I'd like to add that the gut biome differs from person to person, especially with rampant Antibiotic use from people to products that end up on the plate. The care for the sick system is heavily controlled and works backwards thanks to the medico-mafia conglomerates.
Moderation for someone whom might be heavily allergic to something like dairy is counter-intuitive for health.
Nothing is definite. Each of us here is out trying to understand personal health, but not all in the world care and rely on the system to take care of 'em. There's also the lifetime accumulation of differing parasites, virii, bacteria, fungi, and toxins that complicate health maintenance. Physician's can't simply comprehend the complex interaction of differing variables when they do not have all the information they require.