Association of Probiotic Therapy with Survival and Response to Immune Checkpoint Blockade in Patients with Lung Cancer.

Gut dysbiosis caused by antibiotics impairs response to immune checkpoint blockade (ICB). Gut microbiota is becoming an attractive therapeutic target for cancer. The MIYAIRI 588 strain is a probiotic therapy used to improve symptoms related to antibiotic-induced dysbiosis in Japan. We hypothesized that probiotic therapy (CBT) may affect the therapeutic efficacy of ICBs. We retrospectively evaluated 118 patients with advanced non-small cell lung cancer treated with ICBs at Kumamoto University Hospital (Kumamoto-shi, Kumamoto, Japan). Survival analysis comparing patients given CBT before and/or after ICB was conducted using univariate analyses and Cox proportional hazards regression models using propensity score. Propensity score analyses confirmed that probiotic CBT significantly prolonged progression-free survival (PFS) and overall survival (OS). Probiotic CBT significantly associated with longer PFS and OS even in patients who received antibiotic therapy. This study suggests that probiotic CBT may have a positive impact on therapeutic efficacy of ICB in patients with cancer..