The Cancer Microbiome

Human commensal bacteria, also known as the gut microbiome or the micro biodata have shown to impact the cancer phenotypes, its progression as well as response to therapy. This microbiome have shown to produce certain chemicals and metabolites that can have an effect on the cancer development, progression and also can affect the response to chemotherapy. Most studies, till date, have used preclinical mouse models to study the effect of this microbiome over cancer and have successfully established a relationship between this microbiome and cancer phenotypes. Nowadays, the research has shifted towards analysing the impact of this microbiome on the efficacy of cancer therapy specially the immune check point inhibitors, extensively used in cancer treatment these days. In a recent study, it was seen Fecal Microbiome Transplantation (FMT) of stool samples from patients who responded to therapy into germ-free mice improved the effect of immune checkpoint inhibitor therapy in transplanted mice, whereas FMT from non-responding patients did not. Research on the impact of microbiome on cancer has established certain species to be involved in carcinogenesis, classic example of which is H.pylori, a WHO class I carcinogen which can cause gastric cancer, other bacteria causing cancer are fusibacterium spp which is involved in colorectal cancer and patient with colon cancer have shown to have higher amount of Escherichia coli. On the contrary , as discussed earlier microbiota can also influence tumor treatment response specifically immune check point inhibitors. Also, microbiota residing in the tumor environment may contribute to the resistance of chemotherapy by microbial drug resistance. Identifying beneficial microbiome can prove to have positive impact on the cancer treatment outcome. The nutritional supplements of prebiotics or probiotics can be tailored as per the patient requirements and the treatment outcomes can be improved accordingly.