The role of intestinal microbiota and the immune system

Eur Rev Med Pharmacol Sci. 2013 Feb;17(3):323-33.

Abstract

Background: The human gut is an ecosystem consisting of a great number of commensal bacteria living in symbiosis with the host. Several data confirm that gut microbiota is engaged in a dynamic interaction with the intestinal innate and adaptive immune system, affecting different aspects of its development and function.

Aim: To review the immunological functions of gut microbiota and improve knowledge of its therapeutic implications for several intestinal and extra-intestinal diseases associated to dysregulation of the immune system.

Methods: Significant articles were identified by literature search and selected based on content, including atopic diseases, inflammatory bowel diseases and treatment of these conditions with probiotics.

Results: Accumulating evidence indicates that intestinal microflora has protective, metabolic, trophic and immunological functions and is able to establish a "cross-talk" with the immune component of mucosal immunity, comprising cellular and soluble elements. When one or more steps in this fine interaction fail, autoimmune or auto-inflammatory diseases may occur. Furthermore, it results from the data that probiotics, used for the treatment of the diseases caused by the dysregulation of the immune system, can have a beneficial effect by different mechanisms.

Conclusions: Gut microbiota interacts with both innate and adaptive immune system, playing a pivotal role in maintenance and disruption of gut immune quiescence. A cross talk between the mucosal immune system and endogenous microflora favours a mutual growth, survival and inflammatory control of the intestinal ecosystem. Based on these evidences, probiotics can be used as an ecological therapy in the treatment of immune diseases.

Publication types

  • Review

MeSH terms

  • Adaptive Immunity / immunology
  • Gastrointestinal Diseases / immunology
  • Gastrointestinal Diseases / microbiology
  • Gastrointestinal Diseases / therapy
  • Humans
  • Immune System Diseases / microbiology
  • Immune System Diseases / physiopathology
  • Immune System Diseases / therapy*
  • Immunity, Innate / immunology
  • Immunity, Mucosal / immunology
  • Intestinal Mucosa / immunology
  • Intestinal Mucosa / microbiology
  • Intestines / immunology
  • Intestines / microbiology*
  • Intestines / physiopathology
  • Probiotics / therapeutic use*