The gut microbiome can be used to predict the gastrointestinal response and efficacy of lung cancer patients undergoing chemotherapy

Background: Lung cancer has the highest incidence and mortality rate of any cancer worldwide. Platinum-based combination chemotherapy is still the standard treatment for advanced lung cancer. However, the clinical efficacy of this treatment can be affected by its adverse reactions, especially gastrointestinal mucositis. The adverse reactions often lead to delayed and reduced medication. The role played by gut microbiome in the treatment of cancer is becoming clearer, and evidence suggests that regulation of the gut microbiome may affect the response to multiple types of cancer treatment. Methods: Sixty lung cancer patients who received chemotherapy for the first time and 17 healthy subjects were enrolled in this study. A metagenomic analysis of 137 fecal samples was performed using next-generation sequencing technology. Results: The relative abundance of Eubacterium, Ruminococcus, and Faecalibacterium was higher in the lung cancer patients than in the healthy subjects; however, the relative abundance of Prevotella, Streptococcus, Enterococcus, and Roseburia showed the opposite result. The relative abundance of each gut microbiome changed significantly during chemotherapy. At the phylum level, the relative abundance of Firmicutes and Euryarchaeota was dramatically increased after chemotherapy. Lung cancer patients with a higher relative abundance of a particular bacterial genus, such as Prevotella, Megamonas, Streptococcus, Faecalibacterium, Roseburia, Parabacteroides, Coprococcus, Oscillibacter, Dorea, or Chlamydia, at baseline were more likely to experience gastrointestinal reactions. These results show that the intestinal flora can play a role in predicting the effect of chemotherapy in lung cancer patients. Conclusions: The gut microbiome of patients with lung cancer differs from those of healthy people. The results of this study suggest that Ruminococcus and Eubacterium may be related to the occurrence and development of lung cancer. The gut microbiome of lung cancer patients changes significantly after treatment with cytotoxic drugs, which may be associated with the gastrointestinal reaction caused by chemotherapy. The gut microbiome also can be used to predict the efficacy of chemotherapy in lung cancer patients.