The gut microbiome is the main source of microorganisms for the formation of microbiomes of other organs and tissues. Dysbiosis of the intestine and lungs associated with COVID-19 leads to an increase in inflammatory reactions and stimulates the development of a cytokine storm through an increase in the activity of toll receptors. The patient’s intestinal dysbiosis facilitates the invasion of coronaviruses and intensifies inflammatory responses. Conversely, the progression of COVID-19 leads to increased dysbiosis in both the lungs and the intestines. Improving the microbiome through probiotic strains of bifido / lactobacilli and prebiotic substances is an important approach to mitigate the “wave” of COVID-19 at the population level.

The article demonstrates the results of a study to study the comparative assessment of the concentration of ammonia in the peripheral blood of patients with a viral infection of COVID-19 against the background of previously existing hepatic pathology and without it. There was a correlation between peripheral blood hyperammonemia and an increase in the concentration of markers of acute inflammation. The relationship between a high degree of hyperammonemia and a severe course / death as a result of the development of a new coronavirus infection in the studied patients was traced. The role of the initial chronic hepatic pathology (including non-alcoholic fatty liver disease) as a factor in the unfavorable course of the new coronavirus infection is highlighted.

The article presents a modern view of celiac disease within the framework of the classification concept of gluten- associated disorders. The prevalence of the disease, the modern model of the etiopathogenesis of celiac disease, clinical manifestations, and the possibilities of differential diagnosis are discussed. According to the European guidelines, a strategy for monitoring outpatients with celiac disease is presented, based on baseline characteristics of the disease, regular doctor- patient interaction, and prevention of gluten- associated disorders.

The article presents the results of our own research devoted to the study of the functional characteristics of the digestive system in patients with celiac disease associated with connective tissue dysplasia (CTD).

Materials and methods. The study included 90 patients from the register of adults with celiac disease. To assess CTD, patients underwent clinical and laboratory- instrumental examination, including ultrasound of the abdomen organs, kidneys and heart, EGDS. The assessment of the functional state of the gastrointestinal tract was carried out according to the ultrasound data of the abdomen organs, coprogram and PEGEG.

Results. The results of the study showed that all patients had signs of CTD with involvement of at least two organ systems. The most common visceral stigmas of dysplasia were MVP (66.7%), gallbladder anomalies (53.3%), tracheobronchial dyskinesia (35.6%) and signs of nephroptosis (30.0%). Anomalies of the gallbladder included single bends in the body area — 26 people (28.9%) and in the neck area –5 people (5.6%), and double bend — S-shaped gallbladder — 17 people (18.9%). At the same time, an increase in the proportion of gallbladder anomalies was revealed as the severity of CTD increased, with significant differences in the groups in patients with an S-shaped gallbladder (p<0.05), which correlated with biliary sludge and signs of maldigestion. According to PEGEG data, an increase in tonic activity (Pi / Ps) at the frequency of the duodenum with an increase in the degree of CTD was revealed, with the maximum values in group 3 patients being 3.84 ± 1.03, which reflects the presence of hypertensive dysfunction.

Conclusion. The functional state of the digestive system in celiac patients with signs of CTD is characterized by disorders of the gastroduodenal complex and the biliary system. A high degree of CTD in celiac disease patients should be considered as an independent risk factor for motor disorders of the upper gastrointestinal tract and biliary system, which must be taken into account when carrying out therapeutic and prophylactic measures.

Celiac disease is characterized by significant clinical polymorphism, which makes it difficult to diagnose and postpones the start of pathogenetic treatment, ultimately worsening the prognosis of the disease. In this regard, knowledge of the clinical features and variants of the disease is of paramount importance for an effective diagnostic process. The article discusses various options for the clinical manifestations of celiac disease. The possibility of celiac disease should be borne in mind in patients with: 1. a history and clinical manifestations characteristic of celiac disease; 2. symptoms of celiac disease associated diseases; 3. symptoms that may be a manifestation of atypical celiac disease. Relatives of celiac patients are also at risk. Overweight and constipation do not reject the diagnosis of celiac disease. Taking into account all these circumstances will make it possible to diagnose and begin treatment in a timely manner, reasonably counting on its maximum effectiveness

Aim: to compare physical development in children with celiac disease (CD), depending on adherence to a gluten-free diet (GFD), and in children without CD.

Materials and methods: 176 children with gastrointestinal disease were examined. Group 1 consisted of 58 children with newly diagnosed CD and chronic gastritis (CG), before the appointment of a gluten-free diet (GFD), group 2–49 children with CD and CG, adhered of GFD for 1 year, the comparison group consisted of 69 children with CG and duodenitis and excluded CD. The assessment of anthropometric data was carried out using the WHO AnthroPlus software (2009), with the determination of BMI and Z-score values: WAZ, SD; WHZ, SD; HAZ, SD; BAZ, SD.

Results: The groups of participants in the study were homogeneous in terms of gender and age. BMI (16,57±3,29; 1,96 ± 3,96; 18,17±,22; t_1,2=0,573; t_1,3=0,007; t_2,3=0,009). Weight deficiency was more often observed in patients in group 1 (56,8%, 4,1%, 23,2%; P_1,2=0,00; P_1,3=0,00; P_2,3=0,02). Obesity was detected in the groups equally (1,7%, 4,1%, 4,3%; P1,2=0,00; P1,3=0,01; P2,3=0,04). Normal body weight was most common in groups 2 (39,7%, 91,8%, 7205%; P_1,2=0,00; P_1,3=0,01; P_2,3=0,04). HAZ, SD statistically differed in all groups (–0,3928±1,13; 0,0133±1,06; 0,4664±1,15; t_1,2=0,008, t_1,3=0,004, t_2,3=0,031).

Conclusion: normal body weight was most typical for children on GFD. HAZ, SD in children with CD increased in comparison with children with newly diagnosed CD, but it was less, than in group 3. After a one year of GFD, the improvement of weight has a more pronounced dynamics than growth.

The article presents an analytical review of scientific research on celiac disease in children in different countries of the world. The prevalence of atypical manifestations of celiac disease has increased over the past two decades. A number of studies in children with celiac disease show that overweight / obesity at the onset of the disease is not uncommon. In addition, there is a tendency to develop overweight / obesity in patients with celiac disease who strictly adhere to a gluten-free diet. It has been shown that among obese children, the prevalence of celiac disease is comparable to the general population frequency. Thus, the diagnosis of celiac disease should be considered even in children with overweight / obesity, when this diagnosis can be easily missed.

Review article on the problem of celiac disease, which is widespread with diverse range of clinical manifestations and inadequate diagnosis, is presented. The conciderable prevalence of connective tissue disorders in the pediatric population, the important role of connective tissue in the function of all organ systems, including the gastrointestinal system, necessitates studying the impact of the impaired structure and function of connective tissue on the development of celiac symptoms. The paper describes the historical development of the concept of “celiac disease”, the process of studying the pattern of the onset and development of symptoms of the disease; modern studies explaining the varied complex mechanisms of the disease.

The article cites the researchers who studied the role of connective tissue in the structure and function of all body systems with identifying the impact of connective tissue disorders on the development of the gastrointestinal pathology (abnormal motor- tonic activity, reflux disease, dysbiosis, disturbance of autonomic homeostasis) and the manifestation of celiac disease associated with connective tissue disorders.

The conclusion stresses the need to consider the problem of celiac disease as a manifestation of the pathology of the whole organism with the obligatory diagnosis of comorbid diseases, including those associated with connective tissue disorders, which will provide a more successful therapy for celiac disease and an improved prognosis.

Celiac disease is a lifelong disease, associated with lifestyle changes. After the diagnosis was made, patients are faced with a number of tasks: organizing a food system for the patient and his family members at home, in kindergartens, schools, health camps, sanatoriums, hospitals, in the army, while traveling; selection of gluten-free medicines; organization of psychological assistance. Support in the social and psychological sphere of life is provided by patient organizations, that create systems for the comfort life of celiac patients. This review focuses on the role of such organizations in the socio- psychological adaptation of patients with celiac disease. The tasks, methods and projects of systemic educational work, information resources, methods of psychological support for patients are presented; product expertise capabilities, legislative aspects in the field of social and legal protection of the interests of persons with celiac disease and a violation of gluten tolerance, the possibilities of material support for patients in various regions of Russia are highlighted. The article drew attention to the success of patient organizations in improving the quality of life, and those who have difficulties both: the problems of labeling of gluten-free products, the complexity of catering in public restaurants and institutions. The system of activities and projects, developed by the St. Petersburg Society of Celiac Diseases “Emilia” and the National Association “Gluten Free Life” allows to overcome the difficulties, associated with adhering to a strict lifelong diet, improves gluten free food at home.

The article presents a review of retrospective cohort studies of fertility and pregnancy outcomes in women with celiac disease. The article presents the results of our own observations of obstetric and gynecological anamnesis 17 women with celiac disease for the period from 2016 to 2020. Materials and methods. Information collected from patients was analyzed in retrospective cohort studies. Patients with celiac disease and healthy women of reproductive age were included in these studies. Result. The ability of IgA and IgG class antibodies to tissue transglutaminase to disrupt trophoblast invasiveness and endometrial endothelial cell differentiation underlies the failure of early placentation in celiac disease. In the case of the latent course of celiac disease there is an increased risk of recurrent miscarriages and preterm births, impaired growth of the fetus with low birth weight. Conclusion. Given the high percentage of unidentified diagnoses, it is extremely important to identify risk groups for timely treatment and prevention of complications.

The high prevalence of non-carious manifestations in patients with celiac disease is described by numerous authors, who are considered as a diagnostic key to atypical forms of celiac disease. The manifestations closely associated with celiac disease include: defects in tooth enamel, pathological tooth abrasion, as a violation of the mineralization of dental crowns, and morphofunctional defects in the hard tissues of the teeth.

Materials and methods. We examined 45 patients aged 23 to 36 years with a diagnosis of celiac disease, established on the basis of the results of clinical anamnestic, genetic, instrumental studies, morphological study of a biopsy specimen of the intestinal mucosa.

Result. Examination of the dentition of the patients showed that 100% of the examined had pathological abrasion of tooth enamel. Crowded teeth were found in 32 patients. Partial symmetric congenital adentia was diagnosed in 5 patients.

Conclusion. The revealed dentoalveolar anomalies can be attributed to oral manifestations of celiac disease, which is a diagnostic criterion for suspected disease.

The aim of this literature review was to consider the diagnostic value of potential biomarkers detection: citrulline and intestinal proteins, designed to detect intestinal mucosa damage.

Conclusion: determination of I-FABP and I-BABP in blood are promising methods for non-invasive diagnosis of the intestinal damage, since these proteins are released from the damaged enterocytes. However, the determination of intestinal proteins is important in combination with the determination of citrulline. Several studies have shown that citrulline can be measured in animal models, in adult and pediatric patients. It is easily detectable, consistently measured and capable of detecting inflammation of the intestinal mucosa. The limitation of most studies was the small sample size. Non-invasive diagnostic and therapeutic monitoring techniques remain an important area of further research.

Traditionally, inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD). At the same time, there are a number of lesions of the gastrointestinal tract, which can proceed for a long time under the guise of IBD, masking the true cause of the disease. This leads to late diagnosis and, quite often, fatal consequences. These diseases include autoimmune enteropathy (AIE). It is a fairly rare disease characterized by severe diarrhea and immune- mediated damage to the intestinal mucosa.

The aim is to describe the criteria of diagnosis, etiology, pathogenesis, epidemiology, clinic and treatment of AIE in children based on an analysis of modern literature.

Results. Diagnostic criteria for AIE include chronic diarrhea (lasting more than 6 weeks), malabsorption syndrome, specific histological findings from small bowel biopsy with the exclusion of other causes of villous atrophy. An additional criterion is the presence of antibodies against enterocytes or goblet cells. There are: (1) AIEs associated with syndromes such as IPEX and APECED; (2) an isolated form of GI AIE with antibodies against enterocytes without diseases of the digestive system; and (3) any form of AIE in girls associated with any other autoimmune phenomena. To date, at least five subtypes of AIE are known: Primary AIE (pediatric); Syndromic AIE (pediatric); Primary (sporadic) EIA of adults; Secondary (iatrogenic) AIE of adults; Paraneoplastic AIE. Patients with AIE may have associated autoimmune diseases, including diabetes mellitus, autoimmune hepatitis, alopecia, hypothyroidism, and interstitial nephritis. AIE. is a complex disease and potentially life-threatening, the mortality rate reaches 30% in pediatric practice. The prognosis depends on the age of onset of the disease, the severity of symptoms and the degree of histological damage to the gastrointestinal tract. Along with nutritional support, immunosuppressive therapy, the use of therapy based on modern knowledge in the field of molecular biology can help control the disease.

Gluten represents an alcohol- soluble fraction of endosperm proteins of some cereals (wheat, rye, barley). The molecular characteristics of gluten, in particular, the high content of proline in the composition, determines its high resistance to human gastric, pancreatic and intestinal enzymes. Accordingly, gluten peptides retain their immunogenicity when they enter the internal environment of the body, which determines their ability to activate both the innate and adaptive immune response, and maintain pathological immune- mediated reactions that underlie the complex of gluten- associated diseases and pathological conditions. The question of how gluten consumption may be associated with various neurological disorders continues to be discussed. Despite the lack of sufficient objective evidence, the peculiarities of gliadin metabolism suggest the possibility of an association between the consumption of gluten- containing products with the development of neuropsychiatric disorders.. Of particular interest is the efficacy of gluten-free diet in the complex therapy of such diseases as autism, schizophrenia, as well as some neurological disorders, including chronic fatigue syndrome, various cognitive impairments, depression, etc. The article presents a number of research results, as well as discusses the potential mechanisms of the neurotropic action of gluten. The article discusses the potential metabolic and immunological mechanisms of the neurotropic action of gluten, analyzes the literature data regarding the effectiveness of a gluten-free diet in various neurological diseases and psychiatric disorders.

Post-infectious irritable bowel syndrome — one of the most frequent conditions diagnosed in pediatric gastroenterological practice. According to numerous research parisitosis contributes to the chronology of gastrointestinal tract pathology. it is known that the infection Lamblia intestinalis can increase the risk of developing post-infectious IBS, changing species composition and diversity of the intestinal microbiota, modulating metabolism of the host, the nature of the immune response and adversely affecting the mucosal barrier and the motility of the digestive tract. Importantly, the prevalence of giardiasis in patients with symptoms of IBS and dyspepsia at the moment, it remains at a high level. Further research into the pathogenesis of Lamblia intestinalis infection in patients with IBS will be of great importance in medicine.

The article presents a clinical case of the latent course of celiac disease with diagnosis in the adult period, reflects the role of trigger factors, the features of the clinical course, the formation of concomitant lactase deficiency and the need for all diagnostic stages for diagnosis.

The presented article is devoted to the association of celiac disease and alopecia areata. The authors report the clinical significance of specific cutaneous manifestations as diagnostic markers of celiac disease. The article highlights the role of a gluten-free diet in the treatment of alopecia areata and a multidisciplinary approach to patient management.