Human microbiome and malignancy: Principles, mechanisms, and challenges

Abstract

Cancer is a disease caused by several factors, and there are interindividual differences in susceptibility toward cancer. Recent advances in cancer studies have failed to explain the reason as to why out of people exposed to carcinogens or genetically predisposed, only selective individuals develop cancer, while others are not affected. Among the factors that have received attention as a causal factor for cancer development in recent times is the human microbiome. The human microbiome is the genetic material of all the microbes that are present in the human body. A typical human gut microbiome is made up of trillions of organisms, which closes matches with the number of cells in the human body. Also, the genome of these organisms is made up of around 3 million genes, which is much more than the number of genes in the human genome. Microbes induce about 20% of all fatal cancers in humans and therefore provide options for interventions for cancer prevention. With the advent of modern techniques for sequencing, data storage, and analysis, a more detailed analysis of human microbiome is becoming a reality which is paving the way for establishing the relationship between microbiome and cancer. A better understanding of this relationship would equip us to develop new therapeutic and preventive strategies against cancer.