[The superorganism concept in biology and medicine].

The paper discusses the concept of the superorganism of man and his microbiota. A unique and little-known details regarding mutualistic relationship of the host and its microbiome are represented. The main metabolic effects of the gut microbiota of the intestine are described. The use of microbial metabolites as autoregulatory substances in experiments and in clinical practice is discussed. Authors propose an innovative concept of controlled microbiocenosis as a main goal and a priority task of the development of clinically effective probiotics and metabolite preparations (metabiotics).

[Serum metabolome by gas chromatography-mass spectrometry (GC-MS) in patients with ulcerative colitis and celiac disease].

Metabolomics is the emerging science of measurement and analysis of metabolome--the complete set of low molecular weight compounds in a cell, tissue, organ or whole organism. One of the aims of metabolomics is to research the response of an organism to a pathophysiological insult by measuring the concentrations of small molecule metabolites in biofluids and tissues and its dynamics. Intestinal microbiota is most probably involved in the development and maintenance of autoimmune inflammation in ulcerative colitis and celiac disease. Gas chromatography-mass spectrometry (GC - MS) of serum generates comprehensive metabolic profiles, reflecting integrated human (systemic) and gut microbial metabolism which may be altered in disease states. The aim of this study was to investigate GC - MS-based serum metabolomic profiles in UC and CD patients. Serum metabolic profiles were collected from 75 individuals: 20 patients with mild-moderate active UC, 35 CD patients, and 20 healthy controls (HC). We characterized 84 serum metabolites by use GC-MS. 18 metabolites at least have a combined (human + microbial) origin. In serum of UC patients, phenylacetic acid (PAA), 4-hydroxyphenylacetic acid (4-HPAA), 3-indolylacetic acid (IAA), succinic acid (SA) and fumaric acid (FA) were the metabolites most prominently increased, whereas 3-phenylpropionic acid (PPA) was significantly decreased. Serum of CD patients showed significant increases in IAA, 3-indolepropionic acid (IPA), SA and FA. Increased serum levels of succinic acid suggest its possible damaging effect on intestinal mucosa especially in ulcerative colitis. Orally administered butyrate + inulin as supplement to mesalazine in UC or gluten free diet in CD was effective in reducing disease activity with a marked improvement of serum metabolomic profiles (including SA reduction) and gut microbiota in both diseases. There were no any adverse events.

[Regulatory functions of bacterial exometabolites].

This review deals with the issue of growth autoregulation and survival in bacterial cultures under starvation conditions. Based on our results and on published data, the conclusion has been drawn that low-molecular products of metabolism (carboxylic acids, amino acids, and other metabolites) perform regulatory functions. The same compounds also control the ecological relationship between microorganisms at the interspecific level, and affect their antagonistic activity. It is suggested that complexes of bacterial metabolites can be used for controlling the composition of various microbiocenosis, including those of humans.

[Prospects of the development of probiotic preparations on the basis of the "quorum sensing" in bacteria].

The regulation of definite bacterial genes is known to occur, depending on the density of cell population, on the principle of autoinduction named "quorum sensing". The characteristic sign of all regulatory systems working on the principle of "quorum sensing" is the presence of two regulatory proteins: Luxl-like, responsible for the binding of its autoinductor, which makes it possible for the newly formed complex to bind with the promoter of the specific target gene and activate its transcription. The phenomenon of a rise in the concentration of the secreted autoinductor, depending on the increase of the density of cell culture which forms the basis of the "quorum sensing" systems, is analyzed with a view to the development of new therapeutic remedies.

[The bacterial QS-systems and prospects of creation of new metabolic probiotic preparations].

Biological functions of exometabolits of various bacterial species were analyzed from Quorum Sensing position, which showed that the functional activity of microbiocenosis is in many respects determined by the system of metabolic regulation. Possibility of changing the composition of complex microbial communities with low-molecular compounds, products of bacterial cell vital activity, is grounded from theoretical point of view. The authors adduce data on the effects of a synthetic composition on the basis of E. coli metabolites, an ingredient of colibacterin, a probiotic preparation. The preparation demonstrated a high stimulating activity towards a range of microorganisms of normal microflora, and an ability to improve the condition of intestinal epitelial cells. The results may substantiate application of metabolic probiotics for correction of intestinal microflora in man.

[Concept of a probiotic preparation, containing original microbial metabolites].

The biological functions of Escherichia coli M-17 exometabolites, contained in the synthetic composition of the autostimulating preparation "Actoflor-C", were evaluated. As shown by in vitro experiments, the composition had higher stimulating activity with respectto some microorganisms of the normal microflora, in comparison with the prototype preparation "Actoflor". High doses of the preparation "Actoflor-C" were supposedly capable of having not only positive influence on the development of microbiocenosis, but also of producing therapeutic action and primarily on intestinal epithelial cells by compensating the insufficient supply of bacterial metabolites in dysbiotic states. The presented data made it possible to believe that the functional activity of microbiocenosis was greatly determined by the system of metabolic regulation. The presented results formed the basis for the use of bacterial metabolites in the therapeutic of microbiocenosis in man.

[Dynamics and functions of exometabolites in the process of the growth of Escherichia coli M-17 periodical culture].

The concentrations of metabolites altered immediately after culture inoculation into fresh medium and depended on the their dilution (in small dilutions metabolites were released into the medium, and, on the contrary, in great dilutions they were adsorbed). Acetate was the main exometabolite. The growth of culture started only when the acetate concentration reached the threshold value. At the stage of growth deceleration an intensive release of acetate and other exometabolites occurred. The process had the explosive character of chemical chain reaction. It could be initiated by high local concentrations of metabolites around bacteria, most sensitive to changes in growth conditions. At a high concentration of such cells the signal could be transmitted from one bacteria to another, otherwise the reaction chain was quickly broken and no mass release of metabolites occurred. At the stationary phase succinate, valine and lactate were consumed by bacteria with lactate concentration dropping practically to 0. At the same time acetate and citrate concentrations oscillated about some constant value. The release of growth inhibitors, formiate and alanine, continued to the end of cultivation, which was, seemingly, one of the factors of growth cessation. The specific features of the dymamics of metabolites were indicative of the fact that they had their individual regulatory functions. The problem of the self-synchronization of the bacterial culture is discussed.

[Isolation and identification of growth stimulators of Escherichia coli M-17]. / Vydelenie i identifikatsiia autostimuliatorov rosta Eshercichia coli M-17.

The stimulating activity of E. coli M-17 culture fluid (CF) is determined by the action of low-molecular exometabolites, readily soluble in water. The high-molecular fraction was removed from CF by ultrafiltration, the growth stimulators were adsorbed on anion exchange resin and eluated at pH 3.1. In further purification HPLC and chromatography on TSK gel HW-40 were used. The identification of compounds was carried out by the methods of thin-layer chromatography, amino acid analysis and 1H-NMR spectroscopy. Glutamic acid (glutamine) and succinic acid proved to be the most active growth autostimulators. The data of biological testing made it possible to believe that CF also contained less active stimulators and/or synergic substances which had no their own activity, but stimulated growth, acting jointly with other compounds. In view of the definite specificity of action observed in initial CF, some differences in the spectrum of growth stimulators of other E. coli strains may be supposed.

[The action of a preparation of Escherichia coli M-17 growth autostimulants (Actoflor) on the growth of pure and mixed bacterial cultures]. / Deistvie preparata autostimuliatorov rosta Escherichia coli M-17 (Aktoflor) na rost chistykh i smeshannykh kul'tur bakterii.

The effect of the preparation of E. coli M-17 low-molecular exometabolites (Actoflor), containing growth autostimulators, on the growth of pure cultures of E. coli M-17 E. coli K-12, Salmonella enteritidis, Serratia marcescens and Bifidobacterium adolescentis MC-42 was studied. This preparation was shown to stimulate the growth of all above-mentioned bacteria. The addition of Actoflor also led to the acceleration of growth in the cultivation of mixed cultures of E. coli M-17 with E. coli K-12 (or S. enteritidis), the producer strain (E. coli M-17) showing the highest degree of acceleration. Moreover, the action of Actoflor led to the elimination of competitor strains and to the increase of the antagonistic activity of E. coli M-17. Actoflor may be supposedly used as a therapeutic or prophylactic remedy.

[Effect of Actoflor preparations on survival of Escherichia coli M-17 and Salmonella enteritidis under starvation conditions in mixed cultures]. / Vliianie preparatov "Aktoflor" na vyzhivaemost' Escherichia coli M-17 i Salmonella enteritidis pri golodanii v smeshannykh kul'turakh.

The viability of E. coli M-17 and S. enteritidis under starvation conditions in mono- and mixed cultures was studied. E. coli M-17 showed greater capacity for survival in mixed cultures than in monocultures, while for S. enteritidis the contrary was true. Preparations "Actoflor" enhanced the antagonistic activity of E. coli M-17, ensuring its absolute selective advantage under starvation conditions in mixed cultures. The role of E. coli M-17 low-molecular exometabolites is discussed; they are probably an important factor in the antagonistic activity of these microorganisms.

[Oscillation in the number of bacteria during starvation]. / Kolebanie chislennosti bakterii v protsesse golodaniia.

Factors stimulating the increase in the numbers of Escherichia coli bacteria and accelerating their death were studied. It was shown that oscillations in the numbers of viable bacteria are due to periodic changes in the activity of these two factors, which do not coincide in phase. The oscillations in cell numbers occur only at particular cell concentrations.

[Experimental study of the biopreparation Lymphotilin as an antiproliferative and antitumor agent]. / Eksperimental'noe izucheniie biopreparata Limfotilin kak antiproliferativnogo i protivoopukholevogo sredstva.

We found in experiments involving the use of a biopreparation lymphotilin that its administration was followed by a decrease in proliferative activity of cultured tumor cells and a longer survival of mice bearing transplantable leukemia. An intensified intercalation of ethidium bromide in nucleic acids of tumor cells in lymphotilin culture points to the drug activity on nuclear level. Tumor cell inhibition by lymphotilin holds much promise for the practice of hematology.

[Survival of Escherichia coli cells during storage in suspensions of varying concentrations]. / Vyzhivaemost' kletok Escherichia coli pri khranenii v suspenziiakh razlichnoi kontsentratsii.

The presence of positive correlative connection between death rate of Escherichia coli M-17 cells and the density of their suspension have been estimated. It has been shown, that the accumulation in extracellular medium (ECM) of death-stimulating (DS) metabolites, the concentration of which was higher in the suspensions of higher densities, was the immediate cause of the acceleration of death in suspensions with densities higher than 1 x 10(9) cells/ml. DS metabolites could be removed from ECM by adsorption or dialysis, and, thus, they had comparably low molecular mass. The presence of DS metabolites led to the acceleration of death of test-cultures E. coli M-17. The filtrates of ECM of suspensions with density lower than 1 x 10(9) cells/ml did not accelerate the death rate of test-cultures, and, most probably, did not contain any DS-substances. It is supposed, that the role of DS-substances is the maintenance of optimal size of the population of bacteria. The low effective concentrations of these substances make it possible to consider that their functions are nothing but regulatory.