[Role of Neuromediators in the Functioning of the Human Microbiota: "Business Talks" among Microorganisms and the Microbiota-Host Dialogue].

Current concepts concerning social behavior of the microorganisms inhabiting human gastrointestinal tract, as well as their role in the formation of integrated supracellular structures and in intercellular communication in the host-microbiota system are reviewed. Analysis of the literature data and the results obtained by the authors indicate an important role of neuromediators (biogenic amines, amino acids, peptides, and nitric oxide) in the intra- and interspecies microbial communication, as well as in the microbiota-host dialogue. The role of this dialogue for human health, its effect on human psyche and social behavior, and the possibility of construction of probiotic preparations with a goal-directed neurochemical effect are discussed.

Probiotic (symbiotic) bacterial languages.

Symbiotic gut microorganisms release of various soluble low molecular weight (LMW)molecules of different chemical nature (surface and exogenous proteins, nucleases, serpins, sirtuines, other enzymes, lectins, peptides, amines, bacteriocines, fatty and amino acids, lactones, furanons, miRNA, NO, etc). These LMW molecules are able to sense environment, interact with corresponding cell surface, membrane, cytoplasm and nucleic acid receptors, to reply quickly and coordinately by induction of special sets of genes, to support stability of host genome and microbiome, to modulate epigenomic regulation of gene phenotypic expression, to ensure the information exchange in numerous bacterial and bacteria-host systems playing an important role in the control for many genetic and physiological functions, biochemical and behaviour reactions, in supporting host health in general. Various symbiotic (probiotic) strains produce different spectrum of such LMW molecules. There is chemical and functional similarity between LMW molecules synthesized by host eukaryotic cells, indigenous and probiotic microorganisms and some micronutrients. It means many LMW compounds of different origin may be the universal regulators contributing to the transmission of information, quorum sensing effects, metagenome stability and epigenomic control for cell growth and development as well as phenotypic expression of different genes. Knowledge accumulated concerning molecular languages of symbiotic microorganisms allows us to better understand the mode of action of known probiotics and to design in principle novel probiotics (metabiotics) with increased health effectiveness. Now we are only at the beginning of a new era of molecular personal biotherapy and nutrition. Soon we can successfully manipulate both the host and its microbiota through interfering in their cross talk, stability and epigenomic regulation of expression of genes using various types of eukaryotic, prokaryotic and nutrition origin LMW molecules are capable to modulate genetic, metabolic and physiological activities.

[Lectins, adhesins, and lectin-like substances of lactobacilli and bifidobacteria].

Cell-surface adhesion factors of lactobacilli and bifidobacteria, such as lectin/adhesin proteins of S-layers, secreted lectin-like bacteriocins, and lectin-like complexes, are considered and classified in the article. Certain general and specific properties of these factors are noted, such as in vitro and in vivo adhesion, cell co(aggregation), participation in the forming of microbial biofilms and colonization of mammalian alimentary tract, as well as complexation with biopolymers and bioeffectors, specificity to glycanes and natural glycoconjugates, domain and spatial organization of adhesion factors, co-functioning with other cytokines (pro- and anti-inflammatory ones), regulation of target cell properties, and other biological and physiological activities. The authors also note possibilities of application of lectins and lectin-like proteins of probiotic strains of lactobacilli and bifidobacteria in medicine and biotechnology.

[Relationships between the probiotic and host indigenous lactobacilli under the conditions of mixed cultivation in vitro].

Relationships between 5 Lactobacillus manufacturing strains, 458 cultures of indigenous lactobacilli isolated from the human digestive and vaginal tracts and 98 isolates from the feces of white rats and mice were under study. The study demonstrated that under the conditions of mixed in vitro cultivation of paired cultures, probiotic strains inhibited more than 60% of the indigenous lactobacilli isolates. L. acidophilus strain K3 III 24 had the widest spectrum of antagonistic activity. Antagonistic relationships between indigenous lactobacilli depended on the origin, individual features and the anatomical sites of the culture isolation. Based on these results it has to be suggested that probiotic lactobacilli are capable of inducing disbalance in the host indigenous lactoflora. While choosing probiotics the character of relationships between probiotic microorganisms and the indigenous lactobacilli of the future recipient is recommended to be preliminarily tested in vitro.

[Medical microbial ecology: some of the overall results and research prospects].

The review discusses data of fundamental and applied research in human microbial ecology. Having analyzed these data, the author concludes that in the natural habitats these is practically no biochemical process or function of a living organism that would not need a direct or indirect participation of symbiotic organisms. The condition of these organisms should be considered one of the main biogenic factors that determine human health and pathology. The author offers a range of measures that would allow development and introduction of fundamentally new approaches to prevention and treatment of the most wide-spread diseases, as well as application of microorganisms of normal intestinal microflora of man in industrial biotechnology.

[Antimicrobial effects of medicines which are not antibiotics]. / Antimikrobnye effekty lekarstvennyx preparatov, ne yavlaiushchixcya antibiotikami

The data on antimicrobial activity of 69 different drugs not belonging to the class of typical antibiotics were examined. It was shown that many of them had antimicrobial activity against enterobacteria susceptible and resistant to antibiotics. Some of such drugs were able to eliminate the property of resistance to antibiotics and in particular that to chloramphenicol and tetracyclines. The data are indicative of the fact that many of the so called nonantibiotics have the capacity of active interference with the human microbial ecology.

[Role of anaerobic non spore-forming bacteria in maintaining human health]. / Rol' anaérobnykh nesporoobrazuiushchikh bakterii v podderzhanii zdorov'ia cheloveka.

The paper gives brief information on the fact that anaerobic non spore-forming bacteria take an active part in the metabolism of various substances and imbalance in their microscopic flora may be a trigger in the development of many human diseases. In the past 2 decades, Russia has been using various pharmaceuticals based on bifidobacteria, lactobacilli and their complexes, increasing colonization resistance, normalizing the pool of cholesterol, oxalic acid, free histamine, and making the liver function normally. Special emphasis is laid on the design of functional nutrition products by means of the above bacteria. It is emphasized that the industrial development of functional nutrition will determine human health in the twenty-first century.

[Microbial ecology of laboratory animals as a model in evaluation of the immunomodulating and antimicrobial agents]. / Mikrobnaia ékologiia laboratornykh zhivotnykh kak model' pri otsenke immunomoduliruiushchikh i antimikrobnykh agentov.

Rats with altered microbial ecology and decreased colonization resistance due to neutropenia induced by cyclophosphamide were used as a model for estimating the effect of bacterial polysaccharides (lactulose and exopolysaccharide from Bacillus polymyxa) and fluoroquinolones (pefloxacin). Monotherapy with pefloxacin had a favourable effect both on normalization on the intestinal microflora in the rats and their hemopoiesis (decreased neutropenia). The highest correcting effect with respect to the lowered colonization resistance was observed when pefloxacin was used in combination with exopolysaccharide.

[The pathogenicity factors of bacteria in the genus Acinetobacter]. / Faktory patogennosti u bakterii roda Acinetobacter.

Eighty Acinetobacter strains, isolated in Togliatti from patients with purulent inflammatory diseases, were studied to determine their pathogenicity factors. Out of these 80 strains, 32.5% were found to have enterotoxigenic activity and 46.2%, adhesive activity. They were related to adhesins of the human type and to adhesins of the sheep, rabbit, swine and guinea pig types. But the most important phenomenon established in this study was the combination of different pathogenicity factors detected in Acinetobacter bacteria. Analysis of the combination of pathogenicity factors revealed that 7.5% of Acinetobacter strains had adhesive and enterotoxigenic activity, 15.3% of these strains combined adhesive and hemolytic activity and 1.2% of them were found to be enterotoxigenic and hemolytic. Only 5.0% of Acinetobacter strains were found to carry all there pathogenicity factors simultaneously.

[Effect of antibiotics on fecal excretion of various products of microbial metabolism of aromatic amino acids]. / Vliianie antibiotikov na ékskretsiiu s fekaliiami nekotorykh produktov mikrobnogo metabolizma aromaticheskikh aminokislot.

The model experiments on intact albino rats and those exposed to lincomycin, ampicillin and rifampicin showed that intragastric administration of the three antibiotics to the laboratory animals in therapeutic doses for 8 days induced statistically significant changes in the fecal excretion of n-cresol, indole and skatole, microbial metabolites of aromatic amino acids in the gastrointestinal tract of a macroorganism. The results are in favour of using biochemical tests for rapid diagnosis of the intestinal microflora response to antimicrobial agents.

[The effect of chemical preparations on the biological properties of the intestinal lactobacilli in experimental animals]. / Vliianie khimiopreparatov na biologicheskie svoistva kishechnykh laktobatsill éksperimental'nykh zhivotnykh.

The oral administration of the therapeutic doses of tetracycline, pefloxacin, ampicillin, cephalexin, rifampicin, sisomicin to Wistar rats for 5 days was accompanied by a decrease in the total number of lactobacilli in feces and by changes of the species spectre of these microorganisms. In those rats species, never found in intact animals, could be revealed rather frequently. All antimicrobial preparations administered in this investigation induced a decrease in the proportion of antibiotic-sensitive cultures and led to the selection of strains having multiresistance and increased antagonistic activity with respect to Pseudomonas indicator strain. The possible relationship between the markers antibiotic resistance and antagonistic activity in lactobacilli is discussed.