I've been reading Brain Energy by Dr. Chris Palmer that makes a compelling argument that all mental illnesses are metabolic disorders of the brain

https://brainenergy.com/

This. You can find hundreds if not thousand of testemonies in the keto space where their depresion completely disspeared after between 1 to 6 months on keto or at least their needs to meds drasticaly reduced and their symptoms improved.

I'm a big keto proponent but even so, I have to mention that cutting our shitty foods, with or without keto, losing weight, and moving more, are likely stronger causes of improved mood than Keto itself.

I'm not saying keto can't help with psychological problems, but we should first acknowledge the other multiple, known causative, elephants in the room.

I don't think that has anything to do with keto. If you go from a standard american diet to mediteranian, plant based, keto etc people are going to be feeling better. A large percentage of people that change there diet probably start exercising too.

The keto people don't seem to talk to the microbiome people though.

Keto cuts out things that are bad for the microbiome, but the things it keeps are bad (red meat -> excessive protein and TMAO), and it doesn't feed the bacteria enough (fiber, etc).

Also, keto dieting advice is pretty universal but different people have very different microbiomes, lactose tolerance, etc.

That seems like "bro science". There is no reliable evidence that more protein results in worse health outcomes, and a high protein diet doesn't necessarily imply insufficient fiber.

https://peterattiamd.com/lucvanloon/

May be a circular definition. Farting a lot, meat sweats and smelling bad are negative health outcomes IMO.