[Molecular-and-genetic and molecular-and-biological studies of Bifidobacterium and Lactobacillus representatives]

The article contains the results of molecular-and-genetic studies of representatives of the genera Bifidobacterium and Lactobacillus. Presently, the genomes of B. longum and L. plantarum, whose sizes are 2,256,640 and 3,308,274 nucleotide pairs, respectively, have been totally sequenced. Application of various methods of gene identification and genotyping to investigation of the taxonomy of these microbiota representatives, have enriched our knowledge of the variety of these bacteria, allowed classification of the known and revealing of knew species, vegetating in different biotopes of the human organism. Molecular-and-genetic approaches have clarified the taxonomic position of the industrial strains of lactate bacteria, which are used in food industry, helped to determine the kinetics of the passage of probiotic bifidobacterial and lactobacillic strains through the alimentary tract, and to determine the length of their preservation in the intestines after oral administration. The article also contains data on the therapeutic effect of some probiotics and synbiotics, evaluated by double blind placebo-controlled studies, which included determination of the population level of endogenous and peroral exogenous bifidobacteria and lactobacilli.