Essential tremor is a potential marker of prodromal Parkinson's, which has been fairly conclusively linked to gut microbiota alterations with evidence of dysbio

Essential tremor is a potential marker of prodromal Parkinson's, which has been fairly conclusively linked to gut microbiota alterations with evidence of dysbiosis, transmission to animals via PD feces, and improvement following FMT: https://www.mdpi.com/2673-8007/3/3/67 https://www.mdpi.com/2673-8007/3/3/67 Gut - and oral - dysbiosis have been linked to other neurodegenerative diseases as well, so I'd really encourage you to look into this avenue.