• Volunteering to participate in the study.
• Histologically confirmed diagnosis of Non-Small Cell Lung Cancer (NSCLC).
• Patients must be in an advanced stage (incurable with surgery or radiotherapy) or have metastatic disease (Stage IV).
• Male or female patients aged >18 years.
• Eastern Cooperative Oncology Group (ECOG) Performance Status less than 2.
• Laboratory findings must confirm adequate bone marrow function, indicated by:

White Blood Cell (WBC) count > 2,000/mm9, Neutrophil count > 1,500/mm9, Platelet count > 100,000/mm9

• Previously received treatment with any of the following antibody blockers: anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CD137, or anti-CTLA-4.
• Currently taking probiotic supplements or consuming probiotic bacteria-supported yogurt and similar food supplements.
• Antibiotic utilization within the past month.
• Active interstitial lung disease or a history of interstitial lung disease requiring systemic steroid treatment.
• A condition requiring systemic corticosteroids (greater than 10 mg of prednisone daily or equivalent) or who have received immunosuppressive treatment within 14 days prior to the first dose of the study.
• Presence of uncontrolled adrenal insufficiency.
• Pregnancy or breastfeeding.
• Severe congestive heart failure (Class III or higher according to the New York Heart Association Functional Classification) or a history of myocarditis.
• Uncontrolled cardiac arrhythmia that developed within six months prior to the start of the study.