The role of the microbiota in inflammation, carcinogenesis, and cancer therapy

Eur J Immunol. 2015 Jan;45(1):17-31. doi: 10.1002/eji.201444972. Epub 2014 Nov 13.


Commensal microorganisms colonize barrier surfaces of all multicellular organisms, including those of humans. For more than 500 million years, commensal microorganisms and their hosts have coevolved and adapted to each other. As a result, the commensal microbiota affects many immune and nonimmune functions of their hosts, and de facto the two together comprise one metaorganism. The commensal microbiota communicates with the host via biologically active molecules. Recently, it has been reported that microbial imbalance may play a critical role in the development of multiple diseases, such as cancer, autoimmune conditions, and increased susceptibility to infection. In this review, we focus on the role of the commensal microbiota in the development, progression, and immune evasion of cancer, as well as some modulatory effects on the treatment of cancer. In particular, we discuss the mechanisms of microbiota-mediated regulation of innate and adaptive immune responses to tumors, and the consequences on cancer progression and whether tumors subsequently become resistant or susceptible to different anticancer therapeutic regiments.

Keywords: Cancer; Cancer Therapy; Cancerogenesis; Inflammation; Microbiota.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Review

MeSH terms

  • Adaptive Immunity
  • Animals
  • Antineoplastic Agents / therapeutic use
  • Autoimmune Diseases / drug therapy
  • Autoimmune Diseases / microbiology*
  • Autoimmune Diseases / pathology
  • Biological Evolution
  • Carcinogenesis / immunology*
  • Carcinogenesis / pathology
  • Humans
  • Immunity, Innate
  • Immunomodulation
  • Inflammation / drug therapy
  • Inflammation / immunology
  • Inflammation / microbiology
  • Inflammation / pathology
  • Metagenome / immunology
  • Mice
  • Microbiota / immunology*
  • Neoplasms / drug therapy
  • Neoplasms / immunology
  • Neoplasms / microbiology*
  • Neoplasms / pathology
  • Symbiosis / immunology
  • Tumor Escape


  • Antineoplastic Agents