Recombinant probiotics and their potential in human health

The use of probiotics in the form of whole bacteria to achieve health benefits in humans is evolving by the development of recombinant probiotic bacteria as carriers of specific genes achieving a probiotic effect. Studies have demonstrated that bacteria carrying either the gene for IL-10 or for trefoil factors when given in an animal model or as part of a human trial can ameliorate inflammatory conditions of the colon. Such an approach has the advantages of a long-term delivery, the potential for fewer side effects and utility in many other conditions including other autoimmune diseases, dental caries, candidiasis and allergies. Other health benefits are also under investigation in relation to altering the fatty acid composition of adipose tissue by colonizing the intestine with a bacterium carrying the gene involved in fatty acid metabolism. Not only is the lean body mass advantageously affected but the enzyme is active in inducing apoptosis in cancer cells. Benefits may also be obtained not only by adding a gene but deletion of a gene from a bacterium which modulates the production of pro-inflammatory cytokines or may make the probiotic bacterium act as a more effective delivery system by enhancing colonization