Fig.1. Framework for studying etiology of microbiota-driven carcinogenesis.

To better understand the impact of the microbiota on carcinogenesis in humans, assembly of adequately sized human populations for study is needed. DNA from the human tissue or other samples can then be extracted and sequenced for taxonomic and functional analyses of the microbiota. In parallel, culturing of isolated microbes, studies in animal models, as well as profiling of the immune responses to potential carcinogenic microbes will allow for the discovery of microbiota-associated mechanisms driving carcinogenesis. From what is discovered in the laboratory, prospective and longitudinal human studies will be required to confirm the causal effects of the microbiota on human cancers. Critical study approaches include, for example, studies to confirm that the person is exposed to the microbe of interest prior to disease onset, and approaches to prevent disease such as through vaccination against the implicated microbe.