Gut flora in health and disease

Lancet. 2003 Feb 8;361(9356):512-9. doi: 10.1016/S0140-6736(03)12489-0.


The human gut is the natural habitat for a large and dynamic bacterial community, but a substantial part of these bacterial populations are still to be described. However, the relevance and effect of resident bacteria on a host's physiology and pathology has been well documented. Major functions of the gut microflora include metabolic activities that result in salvage of energy and absorbable nutrients, important trophic effects on intestinal epithelia and on immune structure and function, and protection of the colonised host against invasion by alien microbes. Gut flora might also be an essential factor in certain pathological disorders, including multisystem organ failure, colon cancer, and inflammatory bowel diseases. Nevertheless, bacteria are also useful in promotion of human health. Probiotics and prebiotics are known to have a role in prevention or treatment of some diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacteria, Aerobic / physiology
  • Bacteria, Anaerobic / physiology
  • Bacterial Translocation / physiology
  • Colonic Neoplasms / microbiology
  • Colony Count, Microbial
  • Digestion / physiology
  • Humans
  • Inflammatory Bowel Diseases / microbiology
  • Intestinal Diseases / microbiology*
  • Intestinal Mucosa / microbiology*
  • Probiotics / therapeutic use