The presented clinical practice guidelines of the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The guidelines were approved by the XXIII Congress of the GSSR and the 22nd International Slavonic-Baltic Scientific Forum “St. Petersburg — Gastro-2020 ON-LINE” (St. Petersburg, June 11, 2020).

The autor sconcider the metabolic sindrom from the perspecrtive of the General theory of medicine developed by them — the theory of noospheric–anthropogenic harmoni. The paper analyzes new scientifi c data on the role of exposome, various external and internal factors that lead to the development of Metabolic syndrome. The role of various infection, disbiosis, nutrision factors (microbiota correctors, dietary fiber, etc.) are discussed.

Objective. To study the early clinical and pathophysiological manifestations of gastric cancer in the outpatient phasefor early diagnosis disease.
Methods. A total of 300 outpatient cards of patients treated in Smolensk Oncology Hospital with gastric cancer were analyzed during 2016-2019. Data collection included filling out a questionnaire consisting of 32 questions aimed at clarifying demographic data, diagnosing the symptoms of the disease and their duration, identifying the warning signs, precancerous lesion of the gastric mucosa, previous diagnosis and treatment of H. pylori. The study included patients with gastric cancer aged 31 to 88 years. The mean age of patients was 65.12±9.92 years, the median age was 65.5 years. Among 300 patients, 153 (51%) were male and 147 (49%) were female.
Results. 2.7% (n=8) of diagnosed patients account for young people. 32.7% (n=98) of patients were diagnosed with the stage II cancer, 32.3% (n=97) — with the stage III cancer. The most common symptoms of the disease were epigastric pain — 57% (n=171), dysphagia — 19.3% (n=58), nausea — 15% (n=45), unmotivated weight loss — 12% (n=36) and epigastric burning — 7% (n=21). These symptoms bothered patients up to 6 months in 32.7% (n=98) of cases. Biochemical blood tests (80%, n=192/240), accelerated ESR (76%, n=183/241), decreased hemoglobin (69%, n=178/258), and leukocytosis (48%, n=120/248) were identified as the most common “warning” signs. 24.7% (n=74) of patients had atrophic gastritis preceded the development of gastric cancer, 24% (n=72) — gastric ulcer, 12% (n=36) — polyps of the stomach. The previous diagnostics of H. pylori was carried out only in 1.3% (n=4) of patients.
Conclusions. If a patient, including a young patient, has epigastric pain, primary care physicians should recommend esophagogastroduodenoscopy with biopsies to determine precancerous changes in the gastric mucosa and the presence of H. pylori, followed by eradication therapy.

Identified significant changes in the intestinal microbiome in patients with inflammatory bowel disease (IBD), serve as the reason for therapeutic interventions in order to correct it. Faecal microbiota transplantation (TFM) is an effective treatment for recurrent or refractory Clostridium difficile infections, including in patients with inflammatory bowel diseases receiving immunosuppressive and anticytokine therapy.
The results of studying the effectiveness of TFM using a filtered aqueous suspension of donors feces in the correction of intestinal microbiocenosis in patients with recurrent Clostridial infection (RCT), ulcerative colitis (UC) and irritable bowel syndrome (IBS) are presented. 2 weeks after the introduction of the supernatant, a suspension of fecal microorganism microorganisms in patients evaluated the dynamics of the total content of microorganisms and individual representatives of the intestinal microflora. It was found that the supernatant of an aqueous suspension of donor feces containing microbial exometabolites and other biologically active compounds in the short term has the most pronounced effect on the restoration of normal intestinal microflora only in patients with clostridial infection.

The study is dedicated to one of the most discussed problems of the last decade, not only in gastroenterology, but also in the scientific world. The more knowledge and ideas we have about the composition and function of the microbiota of the human body, in particular the microflora of the gastrointestinal tract, as one of the most populated department by microorganisms of the human body, the better we realize that we are only at the beginning of the this way. The evolution of methods for diagnosing of microbiota from microbiological method to modern molecular genetic techniques to isolate the genetic material of bacteria, of course, plays a key role in our understanding of this issue, attempts to establish the role of microorganisms in the development of diseases of various human systems. Inflammatory bowel diseases, including ulcerative colitis, belong to pathological conditions with an unclear etiology characterized by a chronic severe course, a diverse clinical picture, difficulty in establishing a diagnosis, long-term treatment. In this research with the modern diagnostic methods an attempt is made to come closer to understanding the changes that occur in the intestinal microbiota with ulcerative colitis, identifying probable etiological and pathogenetic agents, and identifying possible targets for exposure as additional methods of treating the disease.

The aim of the research: to study the possibilities of transient and two-dimensional shear wave elastography in the diagnosis of fibrosis in chronic diffuse liver diseases of non-viral etiology
Materials and methods: the study included 415 male patients aged 19 to 54 years (average age 40.4 ± 7.8 years), including 156 with non-alcoholic fatty liver disease, 66 with alcoholic liver disease, 122 with fatty disease liver alcohol-metabolic etiology, 68 people without liver disease. The examination plan included the measurement of anthropometric indicators, a biochemical study of blood serum, an ultrasound study of the hepatobiliary zone, a morphological study of liver tissue, transient and two-dimensional shear wave elastography.
Results: according to the results of transient and two-dimensional shear wave elastography, the degree of fibrotic changes with combined alcohol-metabolic liver disease is higher than with isolated exposure to an alcoholic or metabolic factor; the highest diagnostic significance in elastographic research methods was noted in the third and fourth stages of fibrosis, in the second stage, the quality of the diagnostic model in transient elastography was higher than in two-dimensional shear wave.

According to the results of the study in the main group of patients who received complex treatment (IPP and neuroleptic), there was a significant positive dynamics of the main clinical manifestations, compared with the control group. All patients reported a significant decrease in the intensity of heartburn and pain.
The use of probulin with vegetative-corrective action in the complex treatment of patients with GERD with vegetative dystonia syndrome allowed to more effectively stop the painful manifestations and reduce the emotional experience of bodily discomfort, improve the emotional state and mental health of patients, as well as improve their quality of life.

Purpose of the study. Assessment of metabolic status in patients after bariatric surgery.
Materials and methods. 29 patients with I-III degree obesity were examined. Clinical metabolic and micronutrient status was assessed for patients.
Results. For patients after bariatric intervention, a more pronounced decrease in muscle mass during weight loss, an increase in the rate of oxidation of carbohydrates, a decrease in the rate of oxidation of fats, a decrease in the concentration level in the blood serum of a number of indicators of vitamin and mineral status (vitamin D, B12, iron, calcium) is characteristic.

The therapeutic tactics for pancreatic pseudocysts have changed dramatically over the past decade. Currently, due to the rapid development of minimally invasive technologies, the frequency of their use in the treatment of patients with pseudocysts has become widespread, displacing traditional methods of surgical treatment. Nevertheless, surgical treatment of a pseudocyst is justified when other methods of treatment have been ineffective, namely in the case of recurrence of the pseudocyst, with suspected cystic neoplasia of the pancreas, the presence of stenosis of the common bile duct or duodenum, as well as with complicated cysts. The purpose of this article is a literature review of methods and approaches to the surgical treatment of pancreatic pseudocysts, as well as the treatment of vascular complications in this pathology.

The lecture is devoted to a new direction in clinical medicine — the possibility of using artificial intelligence — the field of computer science, which is engaged in modeling the method of acquiring and using knowledge specific to humans. The basis for a correct diagnosis is a combination of experience, the ability to think and act non-standard in difficult cases. A powerful system of generalization and classification, implemented in intelligent systems, allows you to reduce a huge number of possible situations to a small number of typical situations by which decisions or hypotheses are formed.

An increasing number of gram-negative and gram-positive bacteria have been observed to secrete outer- membrane vesicles (OMVs) during their growth both under physiological and pathological conditions in vitro and in vivo. These cell-derived particles are present in many — if not all — physiological fluids. They can convey the multiple various low weight effector and signal molecules (proteins, nucleic acids, lipids, and carbohydrates) into the bacterial and host cells that have important functions in their intercellular communication and regulation. Involvement of OMVS in the various biological functions of prokariotic and eukaryotic cells make them to be key players in both physiological processes and also in pathological conditions. Additionally, the ability of OMVs to deliver molecules to recipient cell opens the possibility of their use as novel disease biomarkers and as promising drug/therapy agents. In this Review, we describe the mechanisms through which bacterial OMVs can support the host homeostasis and health and induce host pathology or immune tolerance, and discuss the possibility of these OMVs participate in innovative nanobiotechnologies.

The effect of various concentrations of fat hydrolysis products on the pancreatic and gastric juices OPA using casein-fat emulsion (casein + tributyrin, casein + sunflower oil) was studied. It is concluded that the hydrolysis products of sunflower oil, contributes to a significant decrease in pancreatic juice OPA, which are less pronounced under the influence of tributyrin hydrolysis products.
The hydrolysis products of both sunflower oil and tributyrinare less pronounced in an acidic environment to reduce the gastric juice OPA. An increase in the concentration of both sunflower oil and tributyrin in the emulsion with casein contributes to a significant increase in pancreatic juice OPA. At the same time, the effect of tributyrinis less pronounced than when using sunflower oil. At the same time, an increase in the concentration of both tributyrin and sunflower oil to a lesser extent affects the increase in the gastric juice gastric arteries.

Introduction: Serotonin (5-hydroxytryptamine, 5-HT) is a regulatory neurotransmitter and a hormone in the CNS and hole organs, the esophagus including. It is known that serotonin, activating its own receptors, stimulates contractile activity of the esophageal muscles. However, role of different type receptors in the 5-HT induced contractile activity of the esophagus is insufficiently known.
The aim: — to determine which type of 5-HT receptors mediate serotonin dependent contractile activity of the esophagus.
Material and methods: This is a electromyography study of rat esophagus contractile activity under serotonin stimulation of 5-HT3,4 and 5-HT2,1 receptors separately modulated. The role of different serotonin receptors in the 5-HT induced contractile activity of the esophagus was evaluated by measuring the amplitude and frequency of the slow wave electromyogram (EMG) by the noninvasive microelectrodes imposed on the adventitial layer of the esophagus.
Results: Administration of the 5-HT3,4 receptors inhibitors excluded caused by serotonin the increment of EMG activity of the contractile activity of the esophagus. Administration of the 5-HT1,2 receptors inhibitors blocked the serotonin enhanced EMG activity of the esophagus.
Conclusion: Our results indicate that serotonin is the important player in the regulation of the rat's esophagus contractility; 5-HT enhancing effect on contraction of the esophageal smooth muscles is mediated through the activation of 5-HT1,2 receptors expressed on the smooth muscle cells, and by activation of 5-HT3,4 receptors expressed on the ganglion neurons.

The article formulates a hypothesis about the virus-bacterial association SARS-CoV-2 and the representative of the class Mollicutes as the main reason for the development of severe forms of COVID-19.

Currently, in the Russian Federation, as well as throughout the world, there is an increase in allergic diseases, including an increase in the number of gastrointestinal manifestations of allergies. Moreover, along with Ig-E-mediated reactions, anaphylactoid reactions occur due to the excessive release of histamine and other biologically active substances from mast cells. These pathological processes can contribute to exacerbation of functional disorders of the gastrointestinal tract, enhancing subclinical inflammation of the mucous membrane, contributing to the development of visceral hypersensitivity and gastrointestinal motility. At the same time, most medical practitioners do not pay due attention to the possible impact of allergic and pseudo-allergic reactions on the course of irritable bowel syndrome and functional dyspepsia. At the same time, it is necessary to take into account that in the case of the syndrome of low resistance to histamine in most patients, the introduction of restrictions on the diet is sufficient and there is no need to prescribe excess drugs. Given the widespread prevalence of functional disorders of the gastrointestinal tract and their significant impact on the quality of life of patients, it is necessary to search for new methods of prevention and treatment of this group of pathological conditions.

The problem of comorbidity of chronic endometritis and the pathology of the digestive system in women of reproductive age is not well understood. Our studies showed that most of them were overweight in varying degrees of severity and being a risk factor for the development of various metabolic disorders in the body. Clinical data, laboratory and instrumental studies did not allow to exclude the presence of biliary dyskinesia and chronic duodenitis against hepatic steatosis. The interdependence of the effect of the liver, pancreatic-biliary system of the gastrointestinal tract and sex steroid hormones on the lipid spectrum of the blood, as well as on proliferative changes in the myometrium, indicate the importance of studying pathogenetic and sanogenetic mechanisms to address the issues of prevention, treatment and rehabilitation of this category of patients.

Recovery of intestinal continuity is remaining a complex issue in abdominal surgery. Previous operations, such as Hartmann's procedure, are usually done in the emergent setting, often in frail and septic patients. As a result, severe adhesions occur, and recognition of various anatomical structures becomes more difficult.
The article describes a clinical case of EUS-guided recovery of rectum's continuity after complete anastomotic stenosis. The operation “EUS-guided formation of rectosigmoid anastomosis using Lumen-Apposing Metal Stent” was performed.
In order to obtain a stable anastomosis within 6 months, a session of bougienage and 4 sessions of balloon dilatation were performed. Currently, the diameter of the colon at the stricture level is about 14 mm, clinically stricture is not significant.
EUS-guided enterostomy can be used to form an intestinal anastomosis in patients with benign diseases. However, this method alone is not the final method of treatment and requires further supervision of patients.