Probiotics

Abstract

Probiotics are defined as live microorganisms that, when administrated in adequate amounts, confer a health benefit on the host. Bacterial strains selected as probiotics are predominantly from the genera, Bifidobacterium and Lactobacillus, which are indigenous to the human gastrointestinal tract. Probiotic bacteria are selected for potential application on the basis of particular physiological, biochemical and technological properties. The classification and identification of probiotic strains may give a strong indication of their safety and technical applicability; thus, probiotic bacteria have to be accurately identified and characterised at least at the species level. Safety and functionality screening also plays an important role in selection of probiotic straints for human use. Extensive investigations of biological active compounds from probiotic bacteria are directed primarily for the preparation of highly effective therapeutic products. Among these substances are bacterial polysaccharides and polar lipids. The general results of chemical, NMR and serological studies indicate the structural heterogeneity of the surface polysaccharides, which in turn might influence their biological activity, namely, the antigenicity. Current research on biological active compounds from probiotic bacteria is also directed at the elaboration of glycoconjugates products. By employing of new modification of supercritical fluid of carbon dioxide (scCO2), polar lipids of lactic acid bacteria and bifidobacteria can be very effectively extracted. The role of biological active components from probiotic bacteria in treatment and prevention of autoimmune diseases, as well as their possible involvement in pathogenesis of autoimmune thyroid disease and celiac disease by the mechanism of molecular mimicry, was revealed. In prospect, the scCO2 isolation technology of probiotic glycoconjugates may be combined with metabolic engineering and immunological studies in technologies aimed at manufacturing of highly effective therapeutic products.