Antibiotics and outcomes of cancer immunotherapy: An updated meta-analysis and clinical applications.

Antibiotic exposure in 97,850 cancer patients treated with immune checkpoint inhibitors is significantly associated with worse overall survival (HR 1.49, 95% CI 1.34–1.65).

• Why it matters: Antibiotics are a modifiable, under-recognized risk factor for poorer immuno-oncology outcomes as nearly 30% of ICI-treated patients receive them and indications are expanding.
• What they did: The study summarizes antibiotic–microbiome mechanisms of ICI resistance and performs an updated meta-analysis across 116 cohorts, quantifying survival associations for overall and progression-free survival.
• The result: Antibiotic exposure is also linked to worse progression-free survival (HR 1.44, 95% CI 1.31–1.58), supporting stewardship and microbiome-centered strategies to prevent, diagnose, and/or repair dysbiosis.