Inclusion Criteria:
* Willing to sign a written participant consent form.
* Males or females aged 40 or above who have participated in the "Integrated Systematic Geriatric Medical Information to Explore Solutions for Healthy Aging (Pilot Project)," the "Integrated Systematic Geriatric Medical Information to Explore Solutions for Healthy Aging" master planner, or the "Integrated Systematic Medical Information to Explore Solutions for Healthy Aging" project (not subject to exclusion criteria).
* Males or females aged 40-59 who have participated in health checkups for employees of Chang Gung Memorial Hospital, Formosa Plastics Group, or Chang Gung University.
* Those with a medical record of more than one year at Chang Gung Memorial Hospital.
* Those who have resided in Taiwan for more than 180 days in the past year.
Exclusion Criteria:
* Individuals with severe organ abnormalities, such as: heart failure (NYHA Fc ≥ III), chronic obstructive pulmonary disease (hospitalization/emergency room visit or medication adjustment within the past month due to disease worsening), decompensated cirrhosis, hemodialysis, or currently undergoing cancer treatment.
* Individuals with a history of severe autoimmune diseases.
* Individuals with a preliminary cognitive and mental assessment score of \<26 on the Mini-Mental State Examination (MMSE) or ≥5 on the Generalized Depression Scale (GDS).
* Individuals (who agree to undergo brain MRI) who are deemed unsuitable for MRI after evaluation (e.g., those with pacemakers, cochlear implants, or spatial phobia).
* Individuals who have taken antibiotics within the past month.
* Individuals whose hearing, vision, or cognitive impairments affect communication.
* Individuals unable to stand or walk (with a walking aid) or with unsteady gait when walking.
* Those who have undergone follow-up outpatient assessments that may affect cognitive function, including but not limited to stroke, Parkinson's syndrome, Parkinson's dementia, epilepsy, brain tumor, or a history of mental illness such as schizophrenia, severe depression, bipolar disorder, alcohol or drug abuse, or a history of loss of consciousness due to severe head trauma.
* Those currently diagnosed with depression and undergoing treatment.
* Those with a past medical history confirming dementia, depression, etc..
* Those deemed unsuitable by a physician.
