Emerging Issues Regarding the Effects of the Microbiome on Lung Cancer Immunotherapy

Lung cancer remains the deadliest malignancy, with limited effective and long-term therapeutic options. Immunotherapy has revolutionized the therapeutic landscape of lung cancer. However, not everyone with lung cancer responds to immunotherapy, while, inpatients who temporarily derive clinical benefit, resistance eventually develops. The host microbiome has emerged as a pivotal player in cancer growth and progression. It has been implicated in the intricate connections between immune cells and tumor cells, ultimately augmenting immunotherapy efficacy in solid tumors, while simultaneously mitigating the immune-related adverse events associated with this type of treatment. Notably, lung cancer patients who obtain benefit from immunotherapy have been found to be colonized with specific bacterial populations, and it is this observation that the scientific community is trying to exploit, aspiring to improve lung cancer immunotherapy response rates. Delving deeper into the molecular mechanisms underpinning the effects of the microbiome on immunotherapy is an area that we should pay attention to if we want to utilize microbiome modulation in everyday clinical practice. Fecal microbiota transplantation, probiotics, targeted antibiotic interventions, and dietary modifications are among the strategies that are under investigation in clinical trials, with the ultimate endpoint of lengthening the life expectancy of lung cancer patients.