Modulation of immunity and inflammatory gene expression in the gut, in inflammatory diseases of the gut and in the liver by probiotics

Core Tip

Core tip: Probiotics, which include live microorganisms as well as dead bacteria and bacterial molecular components, confer a health benefit to the host when administered in adequate amounts. Most of the published research articles that are devoted to probiotics evaluate the effects of probiotics on the prevention and treatment of diseases. However, only a few of these articles address the mechanism of action of these microorganisms. This paper reviews the mechanisms of action that have been proposed to explain the beneficial effects of probiotics, most of which involve gene expression regulation in specific tissues, particularly the intestine and liver. Several strains of Lactic acid bacteria, Escherichia coli, Propionibacterium, Bacillus and Saccharomyces influence the gene expression in gut and liver cells, leading mainly to anti-inflammatory responses and to the enhancement of immunotolerance to foreign antigens.