• Diagnosis of probable Alzheimer's disease (AD) according to the National Institute on Aging-Alzheimer's Association (NIA-AA) criteria, with disease severity classified as mild, moderate, or severe (i.e., Mini-Mental State Examination \[MMSE\] total score between 0 and 24 points \[inclusive\] at screening and baseline).

• Confirmation of AD pathology per the 2024 revised AD diagnostic criteria (biomarker-defined AD with both Aβ and tau positivity):

• Aβ positivity: Plasma Aβ42/40 ratio ≤0.08 or amyloid-PET positivity (SUVR ≥1.1).

• Tau positivity: Plasma p-tau217 ≥2.5 pg/mL or CSF p-tau181/Aβ42 ratio ≥0.02.

• Age: 50 to 90 years of age (inclusive), with at least a primary school education. Both males and females are eligible.

• Stable medication use: If receiving approved AD therapies (e.g., acetylcholinesterase inhibitors, GV-971, NMDA receptor antagonists), doses must remain stable for ≥12 weeks prior to baseline. Treatment-naïve participants are also eligible. All other non-AD-related permitted concomitant medications must remain stable for ≥4 weeks prior to baseline unless otherwise specified.

• Hachinski Ischemia Scale (HIS) total score ≤4.

• Geriatric Depression Scale-15 (GDS-15) total score ≤4.

• Neuroimaging evidence: Screening CT/MRI showing age-related brain changes or cerebral atrophy.

• Caregiver availability: Participant has a stable and reliable caregiver, as confirmed by the investigator.

• Informed consent: Written informed consent must be provided by the participant or, if the participant lacks decision-making capacity, by a legally authorized representative (in accordance with local laws, regulations, and customs). Participants agree to provide peripheral blood, stool, and urine samples during the study for biomarker analysis.