Figure 2.

Effects of gut microbiome modulation on cancer treatment. Therapies which modulate the gut microbiome, including administration of probiotics or fecal microbiota transplantation, improve the efficacy of cancer treatment. Administration of antibiotics can reduce the efficacy of oxaliplatin and CpG oligodeoxynucleotides chemotherapeutic agents. The use of antibiotics increases pathogenic bacteria such as Escherichia shigella and Enterobacter, as well as reduces the anti-cancer effect of 5-FU. Radiation of the pelvic area causes dysbiosis and has the potential to affect the treatment modality of CRC. Furthermore, radiation-induced gut epithelial damage worsens the prognosis of CRC patients. These radiation side effects can be ameliorated through fecal microbiome transplantation as well as probiotics administration. The gut microbiota plays a role in modulating mucosal immunity in the colorectal region, acting to improve the efficacy of immunotherapy by enhancing the CD8+ T cell immune response or SCFA metabolite production.