Human microbiota is a complex consortium of microorganisms involved in the proper functioning of almost every system of the organism. Majority of the human diseases are associated with the development of intestinal dysbiosis. Dysbiotic condition or dysbiosis is a key pathogenic condition causing many severe infectious or non-infectious diseases. Rapid return to the original microbiota in many cases leads to the fast recovery from the disease. However, the optimal way of the treatment of dysbiosis is still under the discussion. Recently we have developed a method of autoprobiotics based on using isolated indigenous bacteria for improving of microbiota condition. The method based on feeding the patients with bacterial products grown from their personal, genetically characterised strains have been successfully tested in clinic on patients with IBS or chronic pneumonia. In present study we tried to evaluate technology employing autoprobiotic bacteria belonging to different species employing the rat model of antibiotic induced dysbiosis. Six experimental groups of animals after taking antibiotics were treated with different variants of autoprobiotics (lactobacillus, bifidobacteria, enterococcus, their mixture, fecal microbiota, or anaerobically grown complex of indigenous microbiota) prepared for each of them before the development of dysbiosis. Judging by the multiple parameters including metagenomics analysis of microbiota, immune status and microbiota content of the animals with dysbiosis relatively to control group, the most pronounced positive changes were provided by autoprobiotics based on enterococci, bifidobacteria or the consortium of indigenous bacteria grown under anaerobic conditions. These groups of autoprobiotics were delivering the most effective restoration of the original microbiota content and significant anti-inflammatory reaction of the immune system.

Исследовано влияние трех штаммов пробиотических бактерий: Lactobacillus rhamnosus K32 (L), Bifidobacterium longum GT15 (B), Enterococcus faecium L-3 (E), на уровни экспрессии и содержания ключевых цитокинов при помощи полимеразной цепной реакции с обратной транскрипцией и иммуноферментного анализа соответственно. В работе использованы культура клеток промоноцитарного происхождения (HTP-1) и экспериментальная модель дисбиоза кишечника. В геномах штаммов В и E ранее были выявлены гены, кодирующие бактериоцины, гены компонентов внешней мембраны, пилей и экзополисахаридов, участвующих в модуляции иммунной системы. При исследовании влияния пробиотических штаммов и их супернатантов на экспрессию цитокинов на культуре клеток выявлено увеличение экспрессии TNFα, обусловленное B, E и супернатантом L. Культура В дополнительно вызывала экспрессию IL-8 и IL-10. При коррекции дисбиоза кишечника у крыс (индуцированного метронидазолом и ампициллином) пробиотиками было показано, что нарушение в составе микробиоты (чрезмерный рост Klebsiella spp., низкое содержание Faecalobacterium prausnitzii) оставались у животных после введения L, как в контроле (без введения пробиотиков). В отличие от этих групп у крыс после введения E и B были выявлены: 1) низкие уровни экспрессии провоспалительных цитокинов (IL-8, TNFα, MCP-1) в брыжеечных лимфатических узлах и содержание данных факторов в сыворотке крови; 2) увеличение содержания в сыворотке крови антивоспалительного цитокина TGF-β. В данной работе, при помощи двух взаимодополняющих моделей, выявлены индивидуальные особенности иммуномодулирующих эффектов пробиотических штаммов L. rhamnosus K32, B. longum GT15 (B), E. faecium L-3, оказывающих различное влияние на микробиоту кишечника.

Streptococcus agalactiae, or group B streptococcus (GBS), is an important pathogen as it is the leading cause of neonatal deaths due to sepsis, meningitis or bacterial pneumonia. Although the development of an effective and safe GBS vaccine is on the agenda of many research labs, there is no GBS vaccine on the market yet. In the present study we attempted to engineer a live vaccine strain based on Bac, a surface protein of GBS, incorporated into a surface fimbrial protein of probiotic Enterococcus. The resulting strain induced specific systemic and local immune responses in mice and provided protection against GBS when administered via the intranasal, oral or intravaginal immunization routes.

Streptococcus pneumonia is an important human pathogen that causes various severe diseases such as pneumonia, otitis and meningitis. Vaccination against S. pneumoniae is implemented in many developed countries. The presently used vaccines are safe, well tolerated but relatively expensive and require modification due to the immunological changes of the epidemic strains. This paper describes the development of a new pneumococcal vaccine candidate for immunization on mucosal surfaces. For this purpose the antigens of chimeric protein PSPF, previously suggested for an injectable S. pneumoniae vaccine, were expressed on the surface of the live probiotic strain Enterococcus faecium L3. Experiments on laboratory mice vaccinated with live bacteria demonstrated the appearance of the specific IgA and IgG which provide protection against the lethal S. pneumoniae infection.

The formation of metabolic changes is based on many factors. In particular, the infectious theory of the development of metabolic “breakdowns” has not lost its relevance. In this regard, many scientists are investigating the role of various microorganisms in the pathogenesis of metabolic syndrome. The review provides the results of current research on the role of Helicobacter pylori (as one of the most well-known and widespread bacterial pathogens) in the pathogenesis of metabolic syndrome. However, the results of scientific work are sometimes contradictory, which dictates the need for novel further research to clarify the characteristics of the influence Helicobacter pylori on the formation of various components of the metabolic syndrome.

The biological effects of three probiotic strains Lactobacillus rhamnosus K32, Bifidobacterium longum GT15, Enterococcus faecium L3 and their mixture were studied using a model of dysbiosis induced in rats by antibiotics. It was found that after taking different probiotics intestinal microbiota changed in a strain-specific manner. The maximal activity against pathogens was revealed after the administration of a mixture of bacterial strains under study or a single strain of enterococci. The strain E. faecium L3 showed the most activity against both Klebsiella spp. and Bacteroides fragilis. It helped to restore the original content of Faecalibacterium prausnitzii. The number of Klebsiella spp. was the same in the group receiving L. rhamnosus K32 and the group of animals, which was not consuming probiotics. Different probiotic strains included in the composition had various immunological effects. Probiotic bifidobacteria, enterococci and the mixture of three probiotics stimulated of mRNA expression of interleukin (IL)-10 in mesenteric lymph nodes. The changes in microbiota after consuming an enterococcal probiotic correlated with an increase in transforming growth factor (TGF)-β and IL-10 content in blood serum and an increase of the intestinal mucus layer. Consumption of L. rhamnosus K32 led to the stimulation of IL-8 expression in mesenteric lymph nodes. Control group not receiving probiotics was characterised by expression of pro-inflammatory cytokines, damage of epithelial cells and the destruction of their tight junctions. The damage to the ultrastructure of the mucosa was prevented in all the groups taking probiotics.