Impact of probiotics use on clinical outcomes of immune checkpoint inhibitors therapy in cancer patients

BACKGROUND: Dysbiosis of the gut microbiota can lead to impaired therapeutic effect of immune checkpoint inhibitors (ICIs). This study aimed to investigate the use of probiotics on the clinical outcomes of cancer patients receiving ICIs therapy. METHOD: PubMed, EMBASE, and the Cochrane Library database were searched to retrieve relevant studies that exploring the relationship between probiotics and the efficacy of ICIs. The primary endpoints included overall survival (OS) and progression‐free survival (PFS), evaluated by the hazard rations (HRs) with 95% confidence intervals (CI), and the secondary endpoint was objective response rate (ORR), evaluated by the odd ratio (OR) with a 95% CI. RESULTS: A total of five studies including 1031 patients were eligible for analysis. Our results indicated that the use of probiotics was associated with a superior OS (HR = 0.50, 95% CI: 0.30–0.85, p = 0.01) and PFS (HR = 0.51, 95% CI: 0.42–0.61, p < 0.01), but had no relationship with ORR (OR = 2.11, 95%CI: 0.51–8.65, p = 0.30) in non‐small cell lung cancer (NSCLC) patients. CONCLUSIONS: Probiotics were positively correlated with OS and PFS in NSCLC patients administrated with ICIs, but had no relationship with ORR.