Randomized, Placebo-Controlled, Double-Blind, 24-Week Proof-of-Concept Study to Evaluate the Safety and Efficacy of L. Lactis CKDB001 in Subjects With Early Alzheimer's Disease

Inclusion Criteria:

1. Male and female adults aged ≥55 and ≤85 years at the time of written consent
2. Subjects with a Korean Mini-Mental State Examination (K-MMSE) score of 20 to 28
3. Have a global Clinical Dementia Rating (CDR) score of 0.5 to 1 and a CDR Memory Box score of 0.5 or greater
4. Subjects who test positive for amyloid on Positron Emission Tomography (PET)

Exclusion Criteria:

1. Subjects with clinically significant diseases other than Alzheimer's disease that may confound cognitive assessment

   • History of central nervous system (CNS) diseases
   • Active central nervous system (CNS) infection capable of affecting cognitive function, or a history of infection resulting in neurological sequelae
   • Structural brain abnormalities identified on screening MRI that could account for cognitive impairment
   • Abnormal thyroid function identified at screening
   • Vitamin B12 deficiency identified at screening

2. History of seizure disorder or epilepsy

3. History or suspicion of alcohol or substance abuse/dependence

4. History of psychiatric disorders, including schizophrenia, bipolar disorder, or clinically significant major depressive disorder, with current active symptoms

5. History of malignancy diagnosed or recurrent within 5 years prior to screening

6. History of a major cardiovascular event within 12 months prior to screening

7. Cardiovascular disease requiring the administration of anticoagulants

8. Severe or active infectious disease requiring treatment with antibiotics or antivirals within 4 weeks prior to randomization, or expected to require such treatment during the study period

9. Clinically significant gastrointestinal disorders within 3 months prior to screening, or conditions that may lead to malabsorption

10. Treatment with any disease-modifying therapy for Alzheimer's disease within 1 year prior to screening

11. Initiation or dosage/regimen changes of symptomatic treatments for dementia within 12 weeks prior to screening

12. Chronic use of medications acting on the CNS or those that may affect cognitive function within 8 weeks prior to screening

13. Regular use of medications that may alter the gut microbiota within 4 weeks prior to screening