They do call the gut the second brain. I know candida in the gut has been implicated in causing symptoms like alzheimers/dementia via breaking down blood brain

They do call the gut the second brain. I know candida in the gut has been implicated in causing symptoms like alzheimers/dementia via breaking down blood brain barrier, even leads to accumulation of plaques like in alzheimers, e.g.: https://www.medicalnewstoday.com/articles/how-a-candida-infection-could-trigger-mechanisms-tied-to-alzheimers https://www.medicalnewstoday.com/articles/how-a-candida-infe... Another vector that I've encountered through personal experience with family members is mold toxins, which transit through the gut and basically keep getting recycled through the gut, so while diseases may begin in the gut, that could also just be pointing to some sort of toxic load that transits through the gut too, e.g. Ochratoxin A if it's mold exposure, etc.