Cirrhosis is the end result of liver fibrosis in chronic liver diseases. Studying the mechanisms of its development and developing measures to slow down and regress it based on this knowledge seem to be important tasks for medicine. Currently, disorders of the gut–liver axis have great importance in the pathogenesis of cirrhosis. However, gut dysbiosis, which manifests as increased proportions in the gut microbiota of Bacilli and Proteobacteria that are capable of bacterial translocation and a decreased proportion of Clostridia that strengthen the intestinal barrier, occurs even at the pre-cirrhotic stage of chronic liver disease. This leads to the development of bacterial translocation, a process by which those microbes enter the blood of the portal vein and then the liver tissue, where they activate Kupffer cells through Toll-like receptor 4. In response, the Kupffer cells produce profibrogenic cytokines, which activate hepatic stellate cells, stimulating their transformation into myofibroblasts that produce collagen and other elements of the extracellular matrix. Blocking bacterial translocation with antibiotics, probiotics, synbiotics, and other methods could slow down the progression of liver fibrosis. This was shown in a number of animal models but requires further verification in long-term randomized controlled trials with humans.

Aim. Current clinical recommendations accentuate current methods for the diagnosis and treatment of irritable bowel syndrome (IBS).Key points.IBS is a functional bowel disorder manifested with recurrent, at least weekly, abdominal pain with the following attributes (any two leastwise): link to defecation, its frequency or stool shape. The symptoms are expected to persist for at minimum three months in a total six-month follow-up. Similar to other functional gastrointestinal (GI) disorders, IBS can be diagnosed basing on the patient symptoms compliance with Rome IV criteria, provided the absence of potentially symptom-causative organic GI diseases. Due to challenging differential diagnosis, IBS can be appropriately established per exclusionem, with pre-examination as follows: general and biochemical blood tests; tissue transglutaminase IgA/IgG antibody tests; thyroid hormones test; faecal occult blood test; hydrogen glucose/ lactulose breath test for bacterial overgrowth; stool test for enteric bacterial pathogens and Clostridium difficile A/B toxins; stool calprotectin test; abdominal ultrasound; OGDS, with biopsy as appropriate; colonoscopy with biopsy. The IBS sequence is typically wavelike, with alternating remissions and exacerbations often triggered by psychoemotional stress. Treatment of IBS patients includes dietary and lifestyle adjustments, various-class drug agents prescription and psychotherapeutic measures.Conclusion. Adherence to clinical recommendations can facilitate timely diagnosis and improve medical aid quality in patients with different clinical IBS variants.

Aim. The study reviews current evidence on digestive system lesions provoked by the new COVID-19 coronavirus infection.Key points. Alongside the destructive impact on respiratory system, COVID-19 manifests itself in gastrointestinal symptoms (nausea, vomiting, diarrhoea) that may precede respiratory signs and prevail in the clinical picture of infection. Patients with chronic inflammatory bowel diseases receiving immunosuppressive therapy are at elevated risk of severe COVID-19 progression. The new coronavirus infection may induce liver damage with increased transaminase activity.Conclusion. Association of digestive system lesions with COVID-19 remains understudied and requires further research.

We have reviewed the currently published results on a role of the gut microflora in a prevention of acute respiratory infections. The main biological properties of probiotic bacteria are presented in a context of their modulating activity on an inflammatory immune response. Available data on the reduction of a possible risk, duration, and severity of respiratory infection symptoms during a probiotic medication intake were analyzed. Potential antiviral probiotic mechanisms have been reviewed and discussed.

Aim.The practical guidelines are intended for primary care physicians, general practitioners, paediatricians, gastroenterologists and general internists to advance the treatment and prevention of gastroenterological diseases in adults and children in therapies with probiotics, prebiotics, synbiotics and their enriched functional foods.Key points.Probiotics are live microorganisms that sustain health of the host when supplied in adequate amounts. Prebiotics include human-indigestible but accessible to gut microbiota substances expediting specific changes in the composition and/or activity of gastrointestinal microbiota that favour the host health. The mechanism of probiotic action comprises the quorum resistance maintenance, nutrient substrate metabolism and end metabolite recycling, macroorganism-sustaining substrate production, as well as the mediation of local and adaptive immune responses.The Russian Federation regulates market differently for biologically active food additives (BAFA), medicinal products (drugs) and functional food products (FFP). We overview the probiotic strains regulated in Russia as BAFAs, drugs and FFPs and provide recommendations on the use of these strains in treatment and prevention of gastroenterological diseases in children and adults.Conclusion.The clinical efficacy of probiotics, prebiotics, synbiotics and fortified functional foods depends on the prebiotic and strain properties and is verified in appropriate comparative clinical trials. Not all probiotics registered in Russia as BAFAs, drugs and FFPs have a strain identity, which provides no warranty of the clinical effect expected. The FFP legislation demands improved regulation mechanisms and control for therapeutic efficacy.

Aim. These recommendations are developed for practitioners in order to familiarize them with modern diagnostic methods, management features and pharmacotherapy of patients with gastroesophageal reflux disease (GERD).General provisions. GERD is the most common reason for patients to visit clinics. There are esophageal and extraesophageal manifestations of GERD. Patients' complaints of heartburn and regurgitation remain the most sensitive and specific clinical manifestations of GERD. The diagnosis of GERD is established on the basis of anamnestic data, instrumental examination (detection of reflux esophagitis during upper gastrointestinal endoscopy, detection of pathological gastroesophageal reflux with 24-hour pH-metry or/and 24-hour pH-impedance monitoring). Patients with suspected GERD and the absence of erosive and ulcerative changes in the mucous membrane of the esophagus or the presence of erosive esophagitis of Grade A according to Los Angeles Classification of Gastroesophageal Reflux Disease are recommended to conduct 24-hour pH-metry on PPI off to exclude or confirm the diagnosis of GERD. Patients with extraesophageal manifestations of GERD without classic symptoms (heartburn, regurgitation) are recommended to undergo 24-hour pH-impedance monitoring with discontinuation of proton pump inhibitor therapy. When deciding on surgical treatment, all patients need to perform high-resolution esophageal manometry and 24-hour pH-impedance monitoring. Complications of GERD include bleeding, strictures, Barrett’s esophagus and esophageal adenocarcinoma. The main groups of medications used in the treatment of GERD are proton pump inhibitors (PPIs), potassium-competitive acid blockers (P-CABs), alginates, antacids, and prokinetics. PPIs are the drugs of choice in the treatment of both symptoms of gastroesophageal reflux disease and existing erosive esophagitis. Combination therapy Rebamipide with PPIs increases the effectiveness of relief of GERD symptoms, as well as reduces the frequency of relapses.Conclusion. These clinical recommendations will improve the quality of medical care for patients with GERD.