The human microbiota presents a highly active metabolic that influences the state of health of our gastrointestinal tracts as well as our susceptibility to disease. Although much of our initial microbiota is adopted from our mothers, its final composition and diversity is determined by environmental factors. Westernization has significantly altered our microbial function. Extensive experimental and clinical evidence indicates that the westernized diet, rich in animal products and low in complex carbohydrates, plus the overuse of antibiotics and underuse of breastfeeding, leads to a heightened inflammatory potential of the microbiota. Chronic inflammation leads to the expression of certain diseases in genetically predisposed individuals. Antibiotics and a “clean” environment, termed the “hygiene hypothesis,” has been linked to the rise in allergy and inflammatory bowel disease, due to impaired beneficial bacterial exposure and education of the gut immune system, which comprises the largest immune organ within the body. The elevated risk of colon cancer is associated with the suppression of microbial fermentation and butyrate production, as butyrate provides fuel for the mucosa and is anti-inflammatory and anti-proliferative. This article will summarize the work to date highlighting the complicated and dynamic relationship between the gut microbiota and immunity, inflammation and carcinogenesis.
Keywords: microbiota, colon cancer, allergy, inflammatory bowel disease, diet
Citation: Greer JB and O’Keefe SJ (2011) Microbial induction of immunity, inflammation, and cancer. Front. Physio. 1:168. doi: 10.3389/fphys.2010.00168
Received: 29 October 2010;
Paper pending published: 29 November 2010;
Accepted: 23 December 2010; Published online: 26 January 2011.
Edited by:Hong Xiang Hui, Southern Medical University, China
Reviewed by:Xiaoning Zhao, Cedars-Sinai Medical Center at Los Angeles, USA
Copyright: © 2011 Greer and O’Keefe. This is an open-access article subject to an exclusive license agreement between the authors and Frontiers Media SA, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence: Stephen John O’Keefe, Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Pittsburgh School of Medicine, 570 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15213, USA. e-mail: firstname.lastname@example.org