Review

Journal of Gastroenterology

, Volume 44, Issue 1, pp 26-46

First online:

Probiotics and immunity

  • Andrea T. BorchersAffiliated withDepartment of Nutrition, Allergy and Clinical Immunology, University of California at Davis
  • , Carlo SelmiAffiliated withDivision of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Genome and Biomedical Sciences FacilityDepartment of Internal Medicine, IRCCS Istituto Clinico Humanitas, University of Milan
  • , Frederick J. MeyersAffiliated withDepartment of Internal Medicine, University of California at Davis Medical Center
  • , Carl L. KeenAffiliated withDepartment of Nutrition, Allergy and Clinical Immunology, University of California at Davis
  • , M. Eric GershwinAffiliated withDivision of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Genome and Biomedical Sciences Facility

Abstract

Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, including the gastrointestinal tract. While this beneficial effect was originally thought to stem from improvements in the intestinal microbial balance, there is now substantial evidence that probiotics can also provide benefits by modulating immune functions. In animal models, probiotic supplementation is able to provide protection from spontaneous and chemically induced colitis by downregulating inflammatory cytokines or inducing regulatory mechanisms in a strain-specific manner. In animal models of allergen sensitization and murine models of asthma and allergic rhinitis, orally administered probiotics can strain-dependently decrease allergen-specific IgE production, in part by modulating systemic cytokine production. Certain probiotics have been shown to decrease airway hyperresponsiveness and inflammation by inducing regulatory mechanisms. Promising results have been obtained with probiotics in the treatment of human inflammatory diseases of the intestine and in the prevention and treatment of atopic eczema in neonates and infants. However, the findings are too variable to allow firm conclusions as to the effectiveness of specific probiotics in these conditions.

Key words

microflora nutritional immunology dietary supplement innate immunity vaccine