Clinical Reviews in Allergy & Immunology

, Volume 22, Issue 3, pp 255–273

Probiotics in clinical conditions

  • Philippe R. Marteau

DOI: 10.1007/s12016-002-0011-0

Cite this article as:
Marteau, P.R. Clinic Rev Allerg Immunol (2002) 22: 255. doi:10.1007/s12016-002-0011-0


Probiotics are nonpathogenic microorganisms which, when ingested, exert a positive influence on the health or physiology of the host. Their mechanisms of action and effects are now studied using the same pharmacological approach as for drugs. This article summarizes and comments on evidence for the positive effects of probiotics in various clinical situations. Substantial evidence can be achieved when randomized controlled trials or meta-analyses show positive results. The clinical situations studied include prevention or treatment of antibiotic-associated disorders, gastroenteritis, and diarrhea, lactose intolerance, intestinal infections and colonization by pathogenic bacteria (including Helicobacter pylori and Clostridium difficile), traveler's diarrhea, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), colonic cancer, urogenital infections and tumors, allergy (especially atopic eczema), vaccination, and cholesterol lowering. Current probiotics have an excellent safety record—another topic discussed in this article.

Probiotics can be defined as nonpathogenic microorganisms which, when ingested, exert a positive influence on host health or physiology (1). They consist of either bacteria, especially lactic-acid bacteria (LAB), or yeast (Saccharomyces), and are increasingly used in foods—especially fermented milks—and pharmaceutical products. Physicians have long been skeptical about their “real” efficacy (2,3), and have raised three basic questions: are probiotic products stable, do they survive in the gastrointestinal tract, and what is the level of evidence for their efficacy? A pharmacological approach was used to assess the positive effects and potential side effects of the products as well as their pharmacokinetics (2,4). The level of evidence for efficacy can be assessed with the rules of evidence-based medicine. We now know that the stability of many products (but not all) is good (5), that many strains (but not all) survive in the gastrointestinal tract (4), and that many double-blind randomized controlled trials (RCT) reported that some probiotics were more efficient than a placebo or a control treatment in specific clinical situations. The effects can be direct or indirect through modulation of the endogenous flora or of the immune system (2). Some effects have clearly been demonstrated, and the level of evidence is still lower for other effects. The article summarizes the present knowledge on the clinical applications of probiotics in humans.

Key words

Probioticsbifidobacteriumlactobacillusintestinal infectionsantibiotic-associated diarrheagastroenteritistraveler's diarrheaintestinal florainflammatory bowel diseasecolonic cancerallergyatopic eczemaoral vaccinationsafety of probiotics

Copyright information

© Humana Press Inc 2002

Authors and Affiliations

  • Philippe R. Marteau
    • 1
    • 2
    • 3
  1. 1.Gastroenterology Department, Hôpital Européen Georges PompidouAssistance Publique des Hôpitaux de ParisParis CEDEX 15France
  2. 2.ISTNA (INSERM U557-INRA U1125-EA CNAM 3200)France
  3. 3.Paris V UniversityFrance