Role of human microflora in health and disease

Eur J Clin Microbiol Infect Dis. 1992 Nov;11(11):1012-5. doi: 10.1007/BF01967791.


The human host and its microbial flora constitute a complex ecosystem whose equilibrium serves as a remarkable example of reciprocal adaptation. Intestinal bacteria play an important role in the development of the immune system. The normal intestinal flora is responsible for resistance to colonization by exogenous pathogenic microorganisms. Nevertheless, it also constitutes a reservoir of potentially pathogenic bacteria in close contact with the host. These bacteria are responsible for opportunistic infections in immunocompromised hosts. The equilibrium of the flora can be upset by antibiotics, leading to infections as a result of proliferation of antibiotic-resistant pathogenic bacteria.

Publication types

  • Review

MeSH terms

  • Animals
  • Bacterial Infections / microbiology*
  • Bacterial Physiological Phenomena*
  • Cross Infection / microbiology
  • Drug Resistance, Microbial
  • Humans
  • Immune System / physiology
  • Intestines / microbiology*
  • Opportunistic Infections / microbiology