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: to optimize outcomes of the treatment and prevention of gastrointestinal diseases in adults and children.   Key points. The Methodological Guidelines contain sections on the terminology, classification, mechanisms of action, requirements for sale in the Russian Federation, requirements for proving the efficacy and safety of probiotics, prebiotics, synbiotics and metabiotics, as well as functional foods enriched with them. An overview of relevant data allowing to include these drugs and products in the treatment an d prevention of gastrointestinal diseases in adults and children is presented.   Conclusion. The clinical efficacy of probiotics, prebiotics, synbiotics and metabiotics depends on the specificity and quantity of their components, the dosage form, the regimen and duration of treatment. Products and functional foods with proven efficacy and safety are recommended for the treatment and prevention of gastrointestinal diseases in adults and children.

Post-covid syndrome (PCS) is a symptom complex that occurs during and after COVID-19 lasting more than 12 weeks, which is not a possible disease. The clinical manifestations of PCS are many-sided, under their mask or manifestations or exacerbations of chronic organic activity, the trigger of which was the virus, are hidden. PCS is a diagnosis of exclusion. The main manifestations of PCS: autonomic dysregulation, cognitive and psycho-emotional disorders, disorders of the respiratory system, cardiovascular, digestive systems. Direct pathogenic factors, the main neurological manifestations are PCS of preservation of brain hypoperfusion, hypoxia and hypoxemia, resulting in energy deficiency of neuronal structures, violation of the probable, as well as virus-induced structural detection of neurons in the cortex and subcortical structures of the brain. The severity and duration of exposure appear to be increasingly dependent on the body's response to SARS-CoV-2. PCS has a different severity of severity in recovered patients and does not always depend on the severity of the acute period. Timely examination with differential diagnosis allows not only to make a diagnosis, but also to recommend therapy with a personalized approach to the correction of PCS.

The authors present current data on the etiology, pathogenesis, clinical manifestations of celiac disease in children of different ages, associated diseases, laboratory and instrumental diagnostics, diet therapy, additional treatment methods, vaccination, and follow-up of children with celiac disease based on the developed clinical guidelines “Celiac Disease. Children”.

Introduction.Stress and stress-induced disorders are not uncommon in pediatric practice. The range of causal stressors (information environment, gadgets, pandemic, armed conflicts, etc.) has expanded significantly these days. The article depicts the main clinical manifestations of stress reactions, pathogenetic mechanisms of their development, provides rational approaches to the therapy of elimination of stress manifestations and consequences in children and adolescents from a pediatric perspective.Objective:To study the influence of stress on the psychoemotional sphere and cognitive functions in children aged 7 to 9 years from the armed conflict zone in the Donbass.Materials and methods. 234 children of primary school age were included in the study, of whom 123 children had lived at the armed conflict zone in Donbass for a year. The psychoemotional state and cognitive functions status were determined by children’s tests using a scoring method to assess test results.Results and discussion.The tests with a scoring method to assess test results showed that 100% of children from the armed conflict zone had a chronic stress, 63% had a moderate to severe stress, a high frequency of various types of phobias, as well as impaired concentration and memory.Therapeutic approaches to the management of stress reactions directly depend on the cause and clinical manifestations of such reactions. The therapy strategy includes among other things general strengthening actions, psychotherapy, symptomatic and pathogenetic methods of treatment. In addition, both acute and chronic stress leads to intracellular magnesium deficiency and increased urinary magnesium wasting, as a large amount of catecholamines is released under stress conditions, which contributes to shifting magnesium out of cells. The magnesium deficiency results in increased permeability of cell membranes for calcium ions, which creates conditions for electrical instability and excessive excitability of cells, most significantly of neurons. This is reflected in the fact that the process of excitation prevails over inhibitory reactions, and stress reactions develop as the clinical manifestations. It has been established that an adequate balance of magnesium increases the adaptive capabilities in people. Its neurotropic effects made it possible to consider magnesium as an effective pathogenetic agent that can increase stress resistance, stress management, and activate the body’s adaptive reserves.Conclusion. The causal stressors are manifold, the paediatrician has to deal with stress reactions in children much more often than doctors of other specialties. Magnesium supplements currently form the basis of treatment and rehabilitation actions in children with stress.