Differences in immunity and survival among non-small cell lung cancer patients: a gut microbiota perspective

OBJECTIVE: This study aimed to investigate the relationship between key gut microbiota [Enterococcus, Escherichia coli (E. coli), Bifidobacterium, and Lactobacillus] and immune function in Chinese patients with non-small cell lung cancer (NSCLC). METHODS: ) were measured using flow cytometry. Analysis was conducted based on 6-month immune checkpoint inhibitor (ICI) efficacy and survival outcomes to examine the relationship between gut microbiota, immune function, and prognosis in NSCLC patients. Pearson correlation coefficients were used to investigate the interrelationships between microbial abundance and immune variables. RESULTS: In the immune checkpoint inhibitor (ICI) responders (R group), higher proportions of Bifidobacteria and Lactobacilli were observed, whereas non-responders (NR group) exhibited increased proportions of Enterococcus and E. coli. Furthermore, Bifidobacteria and Lactobacilli showed positive correlations with T cell counts but negative correlations with inflammatory cytokine levels. Opposing relationships were seen for Enterococcus and E. coli, which correlated negatively with T cells and positively with IL-6 and TNF-α (P < 0.05). CONCLUSION: In NSCLC, Bifidobacterium and Lactobacillus promote beneficial immune feedback loops by activating T cells and exerting anti-inflammatory effects, thereby supporting antitumor immunity.