Treatment Of Dysbiosis Research Articles

Narrative Review: Advancing Dysbiosis Treatment in Onco-Hematology with Microbiome-Based Therapeutic Approach

This review explores the complex relationship between gut dysbiosis and hematological malignancies, focusing on graft-versus-host disease (GvHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. We discuss how alterations in microbial diversity and composition can influence disease development, progression, and treatment outcomes in blood cancers. The mechanisms by which the gut microbiota impacts these conditions are examined, including modulation of immune responses, production of metabolites, and effects on intestinal barrier function. Recent advances in microbiome-based therapies for treating and preventing GvHD are highlighted, with emphasis on full ecosystem standardized donor-derived products. Overall, this review underscores the growing importance of microbiome research in hematology–oncology and its potential to complement existing treatments and improve outcomes for thousands of patients worldwide.

BIOCHEMICAL CHARACTERISTICS OF RAT SALIVA UNDER CONDITIONS OF DYSBACTERIOSIS

Dysbiosis is a condition characterized by the disruption of the normal ratio of microorganisms in the body, which can lead to various physiological disorders. This study investigates the biochemical changes in the saliva of rats under dysbiosis induced by antibiotics. A comparative analysis of the control and experimental groups revealed significant alterations in the levels of albumin, immunoglobulin IgA, electrolytes, and organic acids. The results indicate that dysbiosis leads to an increase in the levels of albumin and electrolytes, as well as a decrease in immunoglobulin IgA, suggesting potential impairments in immune response and metabolism. The findings underscore the importance of maintaining normal microbiota for health and may serve as a foundation for further research in the prevention and treatment of dysbiosis.

Probiotic combinations for women. Effectiveness and safety from the points of evidence-based medicine

To date, probiotic medicinal products have a significant number of clinical studies, which is the basis for the formation of an evidence base and their inclusion in modern treatment standards. However, ideas about the optimal composition of a probiotic preparation and effective dosage remain problematic issues in modern medicine. Choosing an effective probiotic in gynecological practice is a particularly difficult and important issue.Objective of the review: to analyze the available clinical studies aimed at identifying strains of beneficial bacteria, their dosage, possible combinations in order to choose the optimal composition of a probiotic agent for the treatment of dysbiosis, including vaginal.Materials and methods. Modern methods recommended for theoretical analytical research were used: method of analysis, method of synthesis, method of induction. An electronic search was conducted in bibliographic databases, including PubMed, CENTRAL, MEDLINE, Embase, and CINAHL. 58 scientific publications were analyzed. Inclusion criteria were the following keywords: probiotics, optimal dosage, optimal composition, dysbiosis.Results. The most important probiotic microorganisms for restoring health in women are Lactobacillus acidophilus, L. crispatus, L. jensenii, L. gasseri, L. rhamnosus. Each of these lactobacilli maintains the normal vaginal pH, produces hydrogen peroxide, suppresses growth and prevents the reproduction of obligate anaerobes and opportunistic microorganisms when interacting with the peroxidase of cervical mucus.The mechanism of action of the above-mentioned probiotic microorganisms was analyzed. It was established that the effective dose of each of the components should not be less than 1-2 billion colony forming units.Conclusions. The analysis of scientific publications in the bibliographic databases was sufficient to establish that the oral use of probiotics in the treatment of gynecological patients is effective. The optimal components of the probiotic agent, which are effective for the therapy of vaginal dysbiosis, are L. crispatus, L. gasseri, L. jensenii, L. rhamnosus, L. acidophilus.

Pharmacological activity of calcium lactate on a model of dysbiosis in rats

Relevance. Under the influence of endogenous and /or exogenous factors, the intestinal microflora inhabiting all parts of the gastrointestinal tract may change, which disrupts the normal course of physiological processes, and in some cases leads to severe pathological conditions. One of the reasons for the development of intestinal dysbiosis is the use of antibacterial drugs. Thus, the search and development of means for the prevention and treatment of dysbiosis is an urgent task.Goal. The aim of the study was to evaluate the effectiveness of a candidate for a calcium lactate-based drug with repeated intragastric administration on a model of antibiotic-induced dysbiosis in rats.Methods. The study used 40 male Wistar rats (four groups of 10 animals each). A model of antibiotic-induced intestinal dysbiosis was tested in rats by a course of intragastric administration of a combination of amoxicillin and clavulanic acid for 7 days at a dose of 75 mg/kg. The development of dysbiosis was confirmed by a change in the quantitative composition of representatives of the intestinal microbiota. Similarly, for 7 days, the test drug was administered in doses of 5 mg/kg, 25 mg/kg, 125 mg /kg daily 2 hours after the introduction of the pathology inducer. The control group received a 1 % starch solution.Results. The peak of dysbiosis development was recorded on the 4th day of pathology induction. The use of calcium lactate at a dose of 5 mg/kg did not have a significant effect, while in the groups receiving calcium lactate at doses of 25 mg/kg and 125 mg/kg, there was a statistically significant (Mann-Whitney criterion, p < 0.05) decrease in the severity of the pathological process compared with the negative control group.Conclusion. According to the results of this study, it was found that the use of calcium lactate in doses of 25 mg/kg and 125 mg/kg contributed to a faster disappearance of symptoms of dysbiosis and normalization of the intestinal microbiota in comparison with animals that did not receive treatment.

Assessing a relation between composition of luminal and tissue microbiota and cervical intraepithelial changes

The incidence of cervical cancer (CC) in Russia remains at a high level and ranks fourth among all cancers. CC is preceded by mild, moderate, and severe cervical intraepithelial neoplasia. Human papillomavirus (HPV) is known to be the main cause for its development being responsible for 99% cancer cases. Despite HPV infection, the oncological process occurs only under certain conditions. There are risk factors that indirectly affect the course and emergence of cervical dysplasia. In recent years, the role of cervico-vaginal microbiome for onset and progression of this pathology has been actively discussed. Many studies evidence that dysbiosis along with cervical intraepithelial dysplasia is associated with increased HPV viral load, additionally allowing to clarify a role of specific microorganisms. Despite the knowledge rapidly accumulating about the nature of vaginal microbiome in cervical precancerous processes, the level of its impact on disease course has not been fully investigated and is of great interest. Identification of microorganisms that affect emergence and progression of this pathology will allow to prevent and apply select approach to treatment of dysbiosis. The aim of our study was to identify a relation between cervical tissue and luminal culturome and severe cervical intraepithelial neoplasia. The study evaluated the microbiota of cervical and cervical canal mucosa biopsy in patients with cervical intraepithelial changes. According to the study results, the Streptococcus genus representatives were significantly more frequent in cervical biopsy specimens in severe dysplasia vs. no cervical intraepithelial changes, whereas cervical canal cultures provided comparable data. Bacteria from the Corynebacterium genus were found in cervical biopsy specimens 3 times more often than in smear from the cervical canal mucous membrane. The microbiota from cervical and cervical canal biopsy specimens differ qualitatively and quantitatively particularly regarding prevalence of Streptococcus spp. representatives being more common in patients with cervical dysplasia. Corynebacterium spp. were detected more often in cervical biopsy specimens than in cervical canal smears. Thus, the method of collecting biological material has a great influence on final results.

Dysbiosis of the ocular surface – a new risk factor for ophthalmic diseases? The role of eyelid hygiene

Quantitative and qualitative disturbances in the composition of the ocular surface microbiome can be a significant risk factor for the development of various ophthalmic disorders, including eyelid inflammation, dry eye syndrome, and allergic conjunctivitis. In this publication, we present a review of the data regarding the association between dysbiosis and these mentioned clinical conditions. Additionally, we provide recommendations for the treatment of dysbiosis, including eyelid hygiene.

Nanofibers with genotyped Bacillus strains exhibiting antibacterial and immunomodulatory activity.

Biofilm-associated diseases such as periodontitis are widespread and challenging to treat which calls for new strategies for their effective management. Probiotics represent a promising approach for targeted treatment of dysbiosis in biofilm and modulation of host immune response. In this interdisciplinary study, nanofibers with two autochthonous Bacillus strains 27.3.Z and 25.2.M were developed. The strains were isolated from the oral microbiota of healthy individuals, and their genomes were sequenced and screened for genes associated with antimicrobial and immunomodulatory activities, virulence factors, and transferability of resistance to antibiotics. Spores of two Bacillus strains were incorporated individually or in combination into hydrophilic poly(ethylene oxide) (PEO) and composite PEO/alginate nanofibers. The nanofiber mats were characterised by a high loading of viable spores (> 7 log CFU/mg) and they maintained viability during electrospinning and 6months of storage at room temperature. Spores were rapidly released from PEO nanofibers, while presence of alginate in the nanofibers prolonged their release. All formulations exhibited swelling, followed by transformation of the nanofiber mat into a hydrogel and polymer erosion mediating spore release kinetics. The investigated Bacillus strains released metabolites, which were not cytotoxic to peripheral blood mononuclear cells (PBMCs) in vitro. Moreover, their metabolites exhibited antibacterial activity against two periodontopathogens, an antiproliferative effect on PBMCs, and inhibition of PBMC expression of proinflammatory cytokines. In summary, the developed nanofiber-based delivery system represents a promising therapeutic approach to combat biofilm-associated disease on two fronts, namely via modulation of the local microbiota with probiotic bacteria and host immune response with their metabolites.

The Role of Fermented Dairy Products on Gut Microbiota Composition

Milk and dairy products are among the most important foods in the human diet. They are natural and culturally accepted and supply the human body with microorganisms that modulate the intestinal microflora. Improper lifestyles, highly processed diets, and certain drugs may contribute to adverse changes in the composition of the gut microflora. These changes may lead to dysbiosis, which is associated with the pathogenesis of many gastrointestinal diseases. This review aims to determine the effect of fermented milk products on the composition of the gut microbiota and their possible support in the treatment of dysbiosis and gastrointestinal diseases. While most research concerns isolated strains of bacteria and their effects on the human body, our research focuses on whole fermented products that contain complex mixtures of bacterial strains.

Successful experience in the use of teduglutide in children with short bowel syndrome

The article presents an overview of current trends in the approach to the treatment of patients with short bowel syndrome (SBS), including the example of pediatric patients in the Tyumen region. SBC is an extremely rare nosological form in the practice of a clinician and, as a rule, patients with such a diagnosis require a multidisciplinary approach. The most common manifestations of the disease are symptoms of malabsorption: dumping syndrome, progressive weight loss, deficiency of macro- and micronutrients, other manifestations of dyspepsia and abdominal pain. Attention is drawn to the fact that the number and intensity of symptoms varies significantly among patients. The traditional tactic for treating such patients includes the need for lifelong parenteral nutrition or, as a necessary measure, intestinal transplantation. Rehabilitation measures in SBS children should take into account the requirements for correcting impaired absorption and restoring normal trophic status; relief of diarrhea, prevention and treatment of dysbiosis; control and correction of general digestive disorders. We found that the analogue of glucagon-like peptide 2 (GLP-2) - teduglutide - makes it possible to reduce the amount of parenteral nutrition, infusion time, and also achieve a complete transition to enteral autonomy. The method of treatment with Teduglutide is the most promising for patients of this category.

Evaluation of the effectiveness of correction of vagina dysbiosis with the use of vaginal prebiotic complex in women with risk factors of spontaneous premature birth

Dysbiotic changes in microbial ecosystem of the female lower genital tract are risk factors for spontaneous abortions, spontaneous preterm births, intra-amniotic infection, postpartum endometritis, and adverse perinatal outcomes. However, the opinions about the expediency of antimicrobial therapy in women with bacterial vaginosis and a history of preterm birth are controversial, and discussions and the search for an effective method of treatment are still continuing. Treatment of dysbiosis of the vaginal microbiota requires a complex approach for not only the pathogen elimination, but also for the restoring of the normal vaginal biotope. The objective: to evaluate the effectiveness of correction of dysbiotic disorders of the vaginal microbiota in women with risk factors for premature birth using the prebiotic topical therapy.Materials and methods. The studied cohort included 105 women with risk factors for premature birth. I group included 38 women at the stage of pregnancy planning, II group – 39 pregnant women, III group – 28 pregnant women from the moment of their first visit to the female consultation for pregnancy monitor. The control group included 20 conditionally healthy pregnant women at the same gestational age. The patients of the I and II groups after diagnosis of bacterial vaginosis (BV), vulvovaginal candidiasis, or aerobic vaginitis received etiotropic topical therapy in accordance with the recommendations of the Centers for Disease Control and Prevention and International Union against sexually transmitted infections. Bacterial vaginosis was treated by clindamycin cream (2 %) once a day for 7 days; aerobic vaginitis – vaginal tablets which contain 10 mg of dequalinium chloride for 6 days; candida vaginitis – fenticonazole 600 mg in one vaginal capsule once followed by topical application of a prebiotic complex (oligosaccharide, sodium hyaluronate, xylitol, vitamins, lactose) for 10 days. Then pH balance and normocenosis of the vagina were supported by the use of one vaginal capsule of the prebiotic complex per week till the 22nd week of gestation. The pregnant women in the III group with similar pathologies received only classical antimicrobial therapy with antibiotics and/or antifungal drugs.The assessment of the vaginal microbiota was carried out at the time of the patients inclusion in the study and at the 17–19 weeks of gestation by determination of the vaginal pH and using molecular biological and bacterioscopic methods. Results. The effectiveness of BV and mixed vaginitis therapy in all groups was high, the frequency of BV detection after treatment decreased from 28.9 % to 2.6 % in the I group and from 32.1 % to 3.6 % – in the III group.In the I and II groups, in which the patients received complex treatment with the prebiotic complex, the quantity of women with normocenosis of the vagina increased significantly (from 39.5 % to 89.5 % in the I group; from 35.9 % to 89.7 % in the II group), the frequency of the intermediate state of the vaginal microbiota decreased twice (from 13.2 % to 7.9 % in the I group and from 15.4 % to 7.7 % in the II group). In patients of the III group, the incidence of normocenosis increased slightly (from 32.1 % to 39.3 %), but the rate of pregnant women with an intermediate state of vaginal microbiota increased significantly (from 14.3 % to 46.4 %), which is a threat to the recurrence of dysbiotic processes.Conclusions. The topical use of the prebiotic complex, which contains oligosaccharide, sodium hyaluronate, xylitol, vitamins and lactose, is effective in the management of symptoms and pathogenic load in uncomplicated vaginal infection, which is manifested by a decrease in the prevalence of intermediate states of the microbiota and a steady increase in normocenosis. The complex therapy with antibiotics/antifungal agents with a vaginal prebiotic complex provides an effective restoration of the vaginal flora to the state of normocenosis compared to treatment with antibiotics/antifungal agents only.

Ganzya Application of probiotics in treatment of digestive tract dysbacteriosis

This work analyzes the sensitivity of the resident and facultative microbiota of the oral cavity, stomach and duodenum of patients with infl ammatory and erosive — ulcerative diseases of the gastrointestinal tract to probiotic drugs with active ingredients: Bacilus subtilis 534, Lactobacillus acidophilus , Bifi dobacterium bifi dum and Bifi dobacterium longum . The studied microbiota showed a diff erent degree of sensitivity to the Lactobacillus acidophilus , and Bacilus subtilis 534, as well as absolute resistance to Bifi dobacterium bifi dum и Bifi dobacterium longum . Clinicians need to take into account that not all probiotic preparations can be eff ectively used in the treatment of dysbiosis of the digestive tract.

Therapeutic Potential of Metabolites from Lactobacillus rhamnosus and Mare's Milk in the Treatment of Dysbiosis.

Ulcerative colitis is an inflammatory bowel disease that forms ulcerations in the mucous membrane of the colon and rectum, in which gut microbiota plays a pivotal role in its pathogenesis. Agents modulating microbial dysbiosis caused by colitis can help in the remission of this disease. The current study describes the potential therapeutic effects of active metabolites from Lactobacillus rhamnosus and mare's milk which have potential therapeutic values on the intestinal microbiota and proinflammatory cytokines. The analysis of the V1-V3 16S rDNA site revealed significant changes in the intestinal microbiome composition before and after treatment in the treated group compared to the positive control group that was treated with 5-aminosalicylic acid (5-ASA). So the effect of the study product on dextran sulfate sodium-induced dysbiosis was shown to be more potent than the positive control, 5-ASA. The level of proinflammatory cytokines also decreased under the influence of a biological product.

Gut microbiome in non-alcoholic fatty liver disease

Abstract The human gut microbiome is composed of communities of bacteria, viruses and fungi. Bacteria live in each part of digestive tract, increasing their density and changing composition in distal parts. The composition of gut microbiome mainly depends on method of childbirth, age, gender, diet, stress, infections, alcohol intake, diurnal variation, smoking, drugs (antibiotics), physical activity. Dysbiosis is defined as an imbalance or maladaptation in the gut microbial community. This imbalance favors many pathological states and it could be due to some diseases. Non-alcoholic fatty liver disease (NAFLD) has become increasingly common in parallel with the increasing prevalence of obesity and other components of the metabolic syndrome. In year 2020, a more comprehensive new definition of NAFLD was proposed – fatty liver disease associated with metabolic dysfunction (MAFLD). NAFLD/MALFD will become the major form of chronic liver disease in adults and children and could become the leading indication for liver transplantation within a decade. An increased level of Bacteroidetes and decreased level of Firmicutes is observed in fatty liver disease. This imbalance favors the collection of energy and insulin resistance. The prevention and treatment of dysbiosis in NAFLD/MAFLD is essential. The purpose of this review is an understanding related to the dysbiosis and non-alcoholic fatty liver disease in order to help physicians of different specialties in their clinical practice because of growing in population patients with metabolic syndrome and liver steatosis.

Microbiological starter culture of probiotic action in the prevention and treatment of disbacteriosis in heifers and its effect on live weight gain

Scientists of the Bashkir Research Institute of Agriculture of the Ufa Federal Research Center of the Russian Academy of Sciences are conducting scientific research on the development of biotechnological methods for housing and feeding calves of the preweaning rearing period using probiotic drugs. The purpose of the research was to conduct scientific and economic tests of the universal microbiological starter culture of probiotic action Biolax-U for the prevention and treatment of dysbiosis in heifers and to determine its effect on the live weight gain of young animals. Experimental investigations have been conducted in two farms in the Republic of Bashkortostan, where two groups of heifers (control and experimental) of Black-and-White breed of the preweaning rearing period have been formed, selected according to the method of pairs of analogues, taking into account origin, age, live weight. The expediency of using the universal microbiological starter culture of probiotic action Biolax-U as a medicinal product in the diets of calves has been investigated. Feeding of the universal microbiological starter culture of probiotic action Biolax-U allowed us to increase the average daily gains in the live weight of young animals, to improve the functioning of the gastrointestinal tract. It has been found according to the results of control weighings of heifers that the live weight of heifers of the experimental groups was higher by the end of the experiment than the control herdmates in both experiments, and in the first experiment the difference was statistically significant at P < 0,01. It has been found that the absolute gain in the live weight of animals of the experimental groups receiving Biolax-U exceeded the control herdmates in the first experiment by 8,3 kg or 10,0 %, in the second experiment by 7,6 kg or 9,9 % as the result of improving the digestive system, increasing the digestibility and availability of feed in the diet. The heifers of the experimental groups in both experiments had an advantage in terms of average daily gain. For example, in the first experiment this advantage was 93 g/day or 10,0 %, in the second experiment it was 84,4 g/day or 9,9 %.

Дисбіоз кишечника та ефективність використання пробіотика-біоентеросептика Ентерожерміна в його корекції (методичні рекомендації)

У статті подані методичні рекомендації з лікування дисбіозу кишечника. Приділено увагу використанню пробіотика-біоентеросептика Ентерожерміна в комплексному лікуванні даної категорії пацієнтів.

Targeting gut dysbiosis as a means to enhance recovery from surgical brain injury.

Background: Surgical brain injury (SBI) impacts roughly 800,000 people who undergo neurosurgical procedures each year. SBI is the result of unavoidable parenchymal damage, vessel disruption, and thermal injury that is an inherent part of all neurosurgical procedures. Clinically, SBI has been associated with postoperative seizures and long-term neurobehavioral deficits. Current therapies are aimed at providing symptom relief by reducing swelling and preventing seizures. However, there are no therapies aimed at reducing the extent of SBI preoperatively. The microbiome-gut-brain axis may serve as a potential target for the development of new preventative therapies due to its extensive involvement in central nervous system function.Methods: An extensive literature review was conducted to determine whether there is a potential role for dysbiosis treatment in reducing the extent of SBI.Results: Treatment of gut dysbiosis deserves further exploration as a potential means of reducing the extent of unavoidable SBI. Dysbiosis has been correlated with increased neuroinflammation through impaired immune regulation, increased blood-brain barrier permeability, and increased production of reactive metabolites. Recently, dysbiosis has also been linked to acute neurological dysfunction in the postoperative state. Importantly, treatment of dysbiosis has been correlated with better patient outcomes and decreased length of stay in surgical patients.Conclusion: Current literature supports the role of dysbiosis treatment in the preoperative setting as a means of optimizing neurological recovery following unavoidable SBI that results from all neurosurgical procedures.

Effects of nasopharyngeal microbiota in respiratory infections and allergies

The human microbiome, which consists of a collective cluster of commensal, symbiotic, and pathogenic microorganisms living in the human body, plays a key role in host health and immunity. The human nasal cavity harbors commensal bacteria that suppress the colonization of opportunistic pathogens. However, dysbiosis of the nasal microbial community is associated with many diseases, such as acute respiratory infections including otitis media, sinusitis and bronchitis and allergic respiratory diseases including asthma. The nasopharyngeal acquisition of pneumococcus, which exists as a pathobiont in the nasal cavity, is the initial step in virtually all pneumococcal diseases. Although the factors influencing nasal colonization and elimination are not fully understood, the adhesion of opportunistic pathogens to nasopharyngeal mucosa receptors and the eliciting of immune responses in the host are implicated in addition to bacterial microbiota properties and colonization resistance dynamics. Probiotics or synbiotic interventions may show promising and effective roles in the adjunctive treatment of dysbiosis; however, more studies are needed to characterize how these interventions can be applied in clinical practice in the future.

Managing the Microbiome: How the Gut Influences Development and Disease.

The microbiome lies at the forefront of scientific research, as researchers work to uncover its mysterious influence on human development and disease. This paper reviews how the microbiome is studied, how researchers can improve its study, and what clinical applications microbiome research might yield. For this review, we analyzed studies concerning the role of the microbiome in disease and early development, the common methodologies by which the microbiome is researched in the lab, and modern clinical treatments for dysbiosis and their possible future applications. We found that the gut microbiome is essential for proper development of various physiological systems and that gut dysbiosis is a clear factor in the etiology of various diseases. Furthermore, we found that germ-free animal models and microbiome manipulation techniques are inadequate, reducing the efficacy of microbiome research. Nonetheless, research continues to show the significance of microbiome manipulation in the clinical treatment of disease, having shown great promise in the prevention and treatment of dysbiosis. Though the clinical applications of microbiome manipulation are currently limited, the significance of dysbiosis in the etiology of a wide array of diseases indicates the significance of this research and highlights the need for more effective research methods concerning the microbiome.

Perspectives on Probiotics and Bronchopulmonary Dysplasia.

Bronchopulmonary dysplasia (BPD) is a chronic respiratory disease of preterm infants, associated with high morbidity and hospitalization expenses. With the revolutionary advances in microbiological analysis technology, increasing evidence indicates that children with BPD are affected by lung microbiota dysbiosis, which may be related to the illness occurrence and progression. However, dysbiosis treatment in BPD patients has not been fully investigated. Probiotics are living microorganisms known to improve human health for their anti-inflammatory and anti-tumor effects, and particularly by balancing gut microbiota composition, which promotes gut-lung axis recovery. The aim of the present review is to examine current evidence of lung microbiota dysbiosis and explore potential applications of probiotics in BPD, which may provide new insights into treatment strategies of this disease.

Intestinal microbiota as a key factor in the formation of immunity and tolerance. Probiotics capabilities

Introduction. The intestinal microbiome is an integral part of the health of its owner and performs several important functions: metabolic, coordinating, protective, epigenetic, which are closely interactive. In conditions of dysbiosis, disturbances of these functions contributes to different disorders.The intestinal immune system closely interacts with the microbiota. It is represented by all cells: T- and B-lymphocytes, T-regulatory, dendritic cells, macrophages. Micropresentation of antigens occurs through M-cells located between enterocytes. Toll-like receptors that recognize bacterial patterns are presented on the epithelial membrane. Dendritic cells present these antigens to T-cells and direct a further adaptive immune response.The immune system matures as a result of colonization of the intestine with microbiota, which is confirmed experimentally in gnotobiotic animals. Under physiological conditions, the immune system provides tolerance to its own microbiota through Tr-cells. Tolerogenic effects decrease in dysbiotic conditions, as a result, inflammation develops.The state of the intestinal barrier. The intestinal barrier is maintained by microbiota, which stimulates the synthesis of mucin and claudine. In dysbiosis, permeability increases, and the immune system is attacked by microbes and their metabolites, which contributes to inflammation.Dysbiosis predisposes to the development of inflammatory bowel diseases, colorectal cancer, metabolic syndrome and obesity, food allergies. In these diseases, the microbiota loses its diversity and richness and has a predominantly pro-inflammatory effect.The effect of probiotics on the immune system. Probiotics, due to adhesion to the mucous layer, enhance barrier functions, interact with the immune system, affect dendritic cells, promoting the formation of Tr and inhibiting the activation of NF-kB. Commensal metabolites (butyrate) increase the involvement of Tr cells in the colon, exerting a tolerogenic effect.Indications for the appointment of probiotics. Enterococcus faecium and Bifidobacterium longum have proven their activities similar to normal microbiota, and effectiveness in treatment of dysbiosis in children and adults.