FMT+Immunotherapy+Chemotherapy As First-line Treatment for Driver-gene Negative Advanced NSCLC

Participants will receive FMT combined with tislelizumab + pemetrexed + platinum-based treatment (lung adenocarcinoma) / albumin-bound paclitaxel + platinum-based treatment (lung squamous cell carcinoma) for 4-6 cycles. If there is no progression of the disease after 4-6 cycles of the first-line treatment, then patients will enter the maintenance treatment stage. Patients will receive tislelizumab maintenance treatment (lung squamous cell carcinoma), or tislelizumab + pemetrexed maintenance treatment (lung adenocarcinoma).