I have heard many people poo-poo the idea that the immune system has any effect on the brain. It’s not science, they say. All the while, mocking those of us that have chosen to try and reduce internal inflammation (aka, calm the immune system) through herbal remedies and diets.
Science is rooted in observation, is it not. I have observed changes in my son’s cognition and behavior and body as a direct result of herbal remedies which target the immune system. I have watched my mom’s neurological symptoms respond to diet and supplements. These observations have shifted my thoughts and given me hope and reminded me that what we know is incomplete. I, personally, don’t need a scientific study to corroborate my thoughts. But then I’ve never been a believer that what we know of science is absolute. Science is vast and more complex than our pea brains imagine. We should remember that. Because humility is a good thing and we just might be wrong.
But in case you need more fancy shancy science than anecdotal.