Study to Investigate the Effect of L. Lactis CKDB001 Administration on Liver Aminotransferases in Subjects With NAFLD

Inclusion Criteria: * Adult men and women aged 19 to 75 years at the time of written consent * Voluntarily provided written consent after receiving sufficient explanation about the study * ALT or AST levels exceed the upper limit of normal, but are five times or less than the upper limit Exclusion Criteria: * Pregnant or breastfeeding women * Women of childbearing potential and men who are unable or unwilling to use appropriate contraception during the study period * Individuals with a history of alcohol abuse or chronic alcohol consumption: Daily alcohol consumption averaging over 30g/day (210g/week) for men or over 20g/day (140g/week) for women * Individuals with viral or other liver diseases that could affect study results: * Individuals with a history of or current drug abuse * Individuals with a history of psychiatric disorders or current psychiatric conditions that may interfere with the study * Individuals with a history of major gastrointestinal surgery (excluding appendectomy, but including gastric resection, gastrointestinal bypass, anastomosis, bariatric metabolic surgeries) * Individuals with severe comorbidities that make them unsuitable for study participation (e.g., heart disease, kidney disease, malignancy, immunosuppression, etc.): * Regular consumption of probiotics, prebiotics, synbiotics, or fermented milk within 4 weeks prior to screening (participation allowed if consumption ceases at least 1 month before study start) * Regular consumption of medications, health supplements, or herbal remedies that may affect liver function or anti-inflammatory responses within 4 weeks prior to screening (participation allowed if consumption ceases at least 1 month before study start) * Use of medications that may cause hepatic steatosis (e.g., amiodarone, tamoxifen, methotrexate, tetracycline, corticosteroids) * Use of medications for treating non-alcoholic fatty liver disease (NAFLD) or steatohepatitis (NASH) within 3 months prior to screening (e.g., thiazolidinediones, vitamin E) * Use of medications that may affect study results (e.g., antipyretic analgesics, NSAIDs, anti-tuberculosis drugs, antibiotics, anticonvulsants, choleretics, liver disease medications) * Use of oral steroids, hormones, or drugs that may affect absorption, metabolism, or excretion of food within 4 weeks prior to screening (participation allowed if taking systemic steroids or thyroid hormones in stable doses for ≥3 months before screening) * Use of hypoglycemic agents or lipid-lowering drugs (except insulin or thiazolidinediones) with stable doses for at least 3 months prior to screening * Dietary or exercise therapies that may affect study within 3 months prior to screening * Smokers consuming more than 20 cigarettes per day * Allergies or digestive issues related to study food ingredients * Weight loss exceeding 10% of previous body weight within 6 months prior to screening * Participation in another clinical trial within 30 days prior to screening or not completing the required five-half-life period of investigational drug/food from a previous trial * Any other individuals deemed unsuitable for the study by the investigator