Ketogenic diet as something beneficial for certain disorders -- including brain disorders, like epilepsy -- is extremely well established science and readily googled up:
I've also heard that some people experience "miracle cures" eating an all beef diet. Or a vegetarian diet. Or a vegan diet. Or a ketogenic diet. Or from fasting.
The gut biome is barely understood and 70 to 80 percent of the immune cells in the body can be found in the gut. So it shouldn't exactly shock people that messing with diet can have dramatic health effects.
The problem is we aren't at a point of being able to reliably say which weirdo diet to apply to which conditions in some kind of completely reliable fashion and our understanding of why and how those things help is in its infancy.
(I am not a doctor. I don't play one TV. Verifying that what the GP is saying is not straight up crazy talk is not hard at all, though the comment is a hair overenthusiastic as if this is absolutely some kind of solved problem when it probably isn't.)
I think you're right on the money here. We just don't understand anything like a direct cause and effect between all the variables of personal gut biomes and genetics that create the metabolome.
My n=1 experience has been that a fasting-mimicking diet where I emphasize low protein (especially BCAAs) for several days functions as a great reset after I refeed. I think if nothing else people may benefit from "jiggling the handle" metabolic fixes from temporary diet alterations, and various diets may push the microbiome, metabolism, and immune system to a more beneficial state, but that will look different for each person. I also think that starving out various gut bugs of certain nutrients like starches, protein, (yes, we know fat and carbs can be bad in excess. But too much protein isn't often talked about!) sugars, etc. will exert selective pressure on them. The ones that can cooperate with the body will gain over the ones that just extract easy nutrients. And of course, many things like antibiotics just blow away the whole ecology, like burning down a rainforest. It takes a long time to recover.
I like to think of diet as a supply chain: if there's an excess of something, it's going to take cellular work to use it or put it somewhere else for later (e.g. fat, waste). If there's an overabundance of building blocks, the body will not be pushed to scavenge for those from old, broken down cell materials and they'll pile up. So changing the inputs up can give some pathways time to catch up. Fasting in general can also function in that way. The only problem is that it's kind of miserable to do, just like exercise.
https://www.epilepsy.com/learn/treating-seizures-and-epileps...
And here is a scientific paper specifically about schizophrenia and ketogenic diet:
https://pubmed.ncbi.nlm.nih.gov/30037619/
I've also heard that some people experience "miracle cures" eating an all beef diet. Or a vegetarian diet. Or a vegan diet. Or a ketogenic diet. Or from fasting.
The gut biome is barely understood and 70 to 80 percent of the immune cells in the body can be found in the gut. So it shouldn't exactly shock people that messing with diet can have dramatic health effects.
The problem is we aren't at a point of being able to reliably say which weirdo diet to apply to which conditions in some kind of completely reliable fashion and our understanding of why and how those things help is in its infancy.
(I am not a doctor. I don't play one TV. Verifying that what the GP is saying is not straight up crazy talk is not hard at all, though the comment is a hair overenthusiastic as if this is absolutely some kind of solved problem when it probably isn't.)