Aim. This review aims to describe the nature of changes in the intestinal microbiota in irritable bowel syndrome (IBS) and provide a pathogenetic justification of the feasibility of a therapeutic impact on microbiota. 

General findings. An important aspect of the interaction of intestinal bacteria with the “host” cells is their contact with pattern recognition receptors of enterocytes, dendritic cell receptors, as well as a transcellular transport of antigens in the region of Peyer’s patches. The area of interaction of intestinal bacteria and the human body is not limited to the intestines. Intestinal bacteria demonstrate a significant humoral effect due to signalling molecules, some of which exhibit neurotransmitter properties. The study of the bacterial cross-feeding for various species, i.e. mutual use of nutrient substrates produced by bacteria of various species, is of a great interest. The development of a lowactivity inflammation in IBS can partly be explained by the increased interaction of flagellin with the corresponding receptor, as well as the influx of excess bacteria from the small intestine. The majority of studies on IBS have demonstrated the predominance of intestinal bacteria with pro-inflammatory potential (Enterobacteriaceae) and the lack of bacteria with a pronounced anti-inflammatory, antimicrobial and enzymatic action (Lactobacillus and Bifidobacterium), as well as increased mucus degradation. Similar changes are observed in inflammatory bowel diseases. Reduced microbial diversity increases susceptibility to intestinal infections and parasitoses, including those caused by protozoa conditionally pathogenic for adults, such as Blastocystis hominis hominis, Dientamoeba fragilis, Giardia lamblia. With the help of nutrition correction, the use of probiotics and functional foods containing certain probiotic strains, plant fibres (primarily psyllium) and, in some cases, nonabsorbable antibiotics, a positive effect can be achieved in a significant number of IBS patients. Recent works have shown that clinical improvement is accompanied by a change in the composition of the intestinal microbiota.

Conclusion. For the pathogenetic treatment of irritable bowel syndrome, the use of non-drug treatment is justified, such as diet optimization and prescription of plant fibres and probiotic bacterial strains. The positive effect of such an approach is largely determined by modification of the intestinal microbiota composition. This opens up prospects for a further, more targeted impact on the intestinal microbiome.

Despite the similarity of many pathogenetic lesions of the gastrointestinal tract and the oral cavity, there remain unresolved issues related to the etiology and pathogenesis of dental diseases associated with inflammatory bowel diseases.

Aim. Analysis and systematization of literature data on the problem of combined diseases of the oral cavity and the gastrointestinal tract.

Key findings. Severe recurrent inflammatory bowel disease and the close relationship of all levels of the digestive tube create prerequisites for the development of pathological processes in the oral cavity. Despite the extensive symptoms of oral manifestations of inflammatory bowel disease, aphthous stomatitis is considered more often than other diseases. There are different opinions about the involvement of the oral mucosa in the pathological process in inflammatory bowel disease. Some authors consider the defeat of the mouth in terms of the specific localization of Crohn’s disease, others see in it only extraintestinal manifestations of the disease, along with changes in the skin, joints and eyes. Immunohistochemical studies allow you to answer individual questions of pathogenesis.

Conclusion. The presented analysis of publications confirms the morphofunctional unity of various parts of the digestive system, which determines the complex mechanisms of the development of combined diseases.

Aim. To study the prevalence of gastroesophageal reflux disease (GERD) and erosive-ulcerative lesions of the gastroduodenal zone and their association among various age groups of Siberian schoolchildren.

Material and methods. In order to identify gastrointestinal complaints, a cross-sectional survey of schoolchildren at the age of 7–17 years in the settlements of the Republic of Tyva, Evenkia and Buryatia was conducted. In total, 1535 schoolchildren were examined (7–11 years old — 855 and 12–17 years old — 680 people) in Tyva, 790 (7–11 years old — 333 and 12–17 years old — 457 people) in Buryatia and 1369 (7–11 years old — 633 and 12–17 years old — 736 people) in Evenkia. GERD diagnosis in schoolchildren was based on the presence of heartburn complaints following the worldwide consensus on the GERD definition among the pediatric population. An esophagogastroduodenoscopy (283 children in Tyva, 110 in Buryatia and 205 in Evenkia) was performed by random selection in the age groups of schoolchildren with gastrointestinal complaints in each region.

Results. The GERD prevalence among schoolchildren in Siberia was 6.4 %. At the same time, the clinical signs of GERD were mainly noted in schoolchildren of the older age group: at the age of 12–17 years old in 9.4 % of cases, at the age of 7–11 years old in 3.2 % (p = 0.01) of cases. The indicators in the Republic of Tyva were 9.5 %, which is higher than those for schoolchildren in Buryatia (4.1 %; p = 0.01) and Evenkia (4.2 %; p = 0.01). The disease was represented mainly by a non-erosive form. In younger schoolchildren, the non-erosive form of GERD is diagnosed much less frequently and only in Tyva (14.0 %). Erosive esophagitis was diagnosed in 4 cases (0.7 %), 3 of which were in older schoolchildren in Tyva. Erosive-ulcerative diseases of the stomach and duodenum were recorded, to a greater extent, in older children, and largely in Tyva. A more frequent combination of GERD and erosive-ulcerative lesions of the gastroduodenal zone was noted in Tyva, particularly in the older age group.

Conclusion. In Siberian schoolchildren, an association of erosive and ulcerative lesions of the mucosa of the gastroduodenal zone with GERD was established, the severity of which has age-related features and is closely related to the region of residence.

Aim. To analyse the dynamics of morbidity and mortality from diseases of the digestive system, as well as the quality of medical care for gastroenterological patients in the Krasnodar Krai.

Materials and methods. The analysis was carried out according to C 51 “Distribution of deaths by gender, age groups and causes of death” form of the Territorial Authority of the Federal State Statistics Service for the Krasnodar Krai for the period from 2006 to 2018, as well as on the basis of the “Demography” block database of the Parus software of the healthcare management system of the Krasnodar Krai for 6 months of 2019. 1341 medical records of patients receiving outpatient medical care and the medical records of people who had died from digestive diseases in 2017-2019 were reviewed.

Results. Digestive diseases (DD) occupy the fourth place (7.1 %) in the structure of the general morbidity of the population in the Krasnodar Krai. Over the study period (13 years), the structure of mortality from DD has not changed significantly among the region’s population. About 70% of the causes of death from DD among people of working age account for liver diseases. The pathology of the pancreas takes the second place (13.5 %). The peptic ulcer of the stomach, duodenum and “other diseases of the digestive system” (8.8 % and 7.7 %, respectively) are represented in almost equal shares. In the etiological structure of liver cirrhosis, viral (39 %) and alcoholic (36 %) liver diseases are leading. The frequency of viral liver lesions tends to decrease, while the proportion of liver cirrhosis in the outcome of non-alcoholic fatty liver disease (NAFLD) progressively increase, having reached 7 % in 2017–2018. In the group of patients with inflammatory diseases of the pancreas, men prevail (66.9 %), often those abusing alcohol. The third leading cause of mortality from DD in the Krasnodar Territory is pathological conditions that occurred in the upper gastrointestinal tract (acute stomach ulcer, duodenal ulcer with bleeding, perforation) in older age groups taking antiplatelet agents and non-steroidal anti-inflammatory drugs (71.8 %). 

Conclusions. The main causes of death among the population of the Krasnodar Krai from diseases of the digestive system at a young age are alcohol consumption with unhealthy consequences. At the same time, people of older age groups die from a lack of prevention of ulceration and inadequate eradication of Helicobacter pylori in patients taking non-steroidal anti-inflammatory drugs and antiplatelet agents.

Aim. To assess the effect of rifaximin and a multi-strain probiotic on the intestinal microbiome and the indicators of cardiovascular risk in patients with coronary heart disease (CHD).
Materials and methods. A study conducted during the 2016–2019 period included 120 people over 50 years old divided into 3 groups. Group 1 comprised patients with coronary heart disease receiving standard treatment. Group 2 comprised patients with coronary heart disease receiving additionally a probiotic (Bifidobacterium bifidum no less than 1x109 CFU; Bifidobacterium longum no less than 1x109 CFU; Bifidobacterium infantis no less than 1x109 CFU; Lactobacillus rhamnosus no less than 1x109 CFU) within 28 days. Group 3 comprised CHD patients receiving rifaximin for 7 days followed by addition of the multi-strain probiotic under test for 21 days. Group 4 consisted of healthy individuals, comparable in age and sex with the examined CHD patients. In group 4, blood and stool tests were performed once to provide a comparison with group 1. TMAO concentration was determined using liquid chromatography–mass spectrometry. To study the composition of fecal microflora, 16S sequencing was used followed by a graphical representation of the results. The results were analysed using the IBM SPSS 22.0 statistical data processing software.
Results. An additional administration of the probiotic (Bifidobacterium bifidum no less than 1x109 CFU; Bifidobacterium longum no less than 1x109 CFU; Bifidobacterium infantis no less than 1x109 CFU; Lactobacillus rhamnosus no less than 1x109 CFU) is found to have no effect on the lipid profile and the platelet aggregation rate. Rifaximin therapy reduced the amount of total cholesterol, low density lipoproteins (LDL), very low density (VLDL) lipoproteins and triglycerides (p <0.05), although not affecting the level of high density lipoproteins (HDL). TMAO showed a statistically insignificant (p>0.05) downward trend in all groups. The composition of the fecal microbiota, at the end of administration of the probiotic, showed an increase in the proportion of bacteria of the Streptococcaceae, Lactobacillaceae, Enterobacteriaceae families and a decrease in the Ruminococcaceae family (p>0.05). After rifaximin therapy, a decrease in the proportion of bacteria of the Clostridiaceae (p <0.05) and Peptostreptococcaceae (p <0.05) families, a decrease in Enterobacteriaceae (p > 0.05) family and a decrease in the Clostridium and Escherichia/Shigella (p > 0.05) genera was observed. The use of the probiotic after a course of treatment with rifaximin did not have a significant effect on the composition of the microflora. In general, the high variability of fecal microbiota between different patients (significantly superior to intergroup differences) does not allow us to draw unambiguous conclusions.
Conclusions. The use of a multi-strain probiotic as an additional therapy in patients with coronary heart disease within 28 days did not have a significant effect on lipid metabolism, TMAO level and the composition of fecal microflora. The consecutive use of rifaximin and the probiotic had a beneficial effect on such factors as lipid metabolism (decrease in the level of total cholesterol, LDL, VLDL, triglycerides), but did not affect the concentration of TMAO and the composition of the intestinal microflora in patients with coronary heart disease.

Over the period after an exacerbation of chronic liver diseases, patients often retain common symptoms (weakness or fatigue, bad mood, sleep disorder, vegetative disorders — asthenic syndrome). In the context of prevention and treatment of these symptoms, such nutraceutical products as enriched foods in the form of tablets, sachets, etc, have been increasingly attracting research attention.
Aim. To study the efficacy of the “Hepato Smart” nutraceutical product for the treatment of asthenic syndrome in outpatients suffering from chronic diffuse liver diseases with compensated function and functional disorders of the gallbladder over the period after exacerbation.
Materials and methods. The study included 50 patients, with 41 of them having completed the program. The nutraceutical product (curcumin, piperine, tanshinone IIA, choline; standardized for curcumin and choline) was assigned 1 pill 3 times a day with meals for 4 weeks. To objectify common symptoms, we used a D-FIS questionnaire (Daily Fatigue Impact Scale), a 4DSQ Four-Dimensional Symptom Questionnaire for assessing distress, depression, anxiety and somatization, and a SF-36 questionnaire for assessing the quality of life.
Results. Following 4 weeks of the “Hepato Smart” course, a statistically significant decrease in fatigue was noted by D-FIS scores (p = 0.003), as well as a decrease in the level of distress, depression, anxiety and somatization by 4DSQ scores (p = 0.005; p = 0.006; p = 0.003; p = 0.003, respectively). The quality of patients’ life according to the SF36 questionnaire also improved due to both physical and psychological components (p = 0.003). 16 patients continued taking the preparation for another 8 weeks to maintain the achieved result. As an additional effect, the disappearance of pain in the right hypochondrium was noted in those cases when patients presented this complaint at the time of inclusion in the observation program. The safety profile was good, 1/3 of the patients noted the appearance of heartburn, which was eliminated when taking the product with food.
Conclusion. The “Hepato Smart” nutraceutical product improves the general condition of patients with chronic diffuse liver diseases and functional disorders of the gallbladder due to a significant reduction in fatigue and anxiety. It also improves the quality of patients’ life due to the physical and mental components of health. 

Aim. To study long-term results of surgical treatment of patients with familial adenomatous polyposis (FAP) with the cell reconstruction of the rectal mucosa.
Materials and methods. 57 FAP patients were subjected to treatment, which involved colproctectomy, the preservation of the lower rectal ampulla, mucosectomy and the reconstruction of the mucosa by cell transplantation. Endoscopic monitoring was carried out, with the endoscopic observation covering the period of 19–120 months (median — 44.3 months). Morphological and immunohistochemical studies were conducted. The long-term functional results of treatment (anorectal manometry (profilometry)) were studied. The patients were surveyed using the SF-36 questionnaire to monitor the quality of their life.
Results. Our results show that the use of cell transplantation leads to the reconstruction of the rectal mucosa over a fairly short time: in 44/57 (77.2 %) patients, the endoscopic picture corresponded to the unchanged rectal mucosa 4 weeks after the surgery. In 13/57 (22.8 %) patients, a complete mucosal reconstruction was achieved 8–12 weeks after the surgery. The absence of polyp growth in the preserved part of the rectum was observed. Late complications developed only in 5 (9.4 %) patients. Good functional results (acceptable frequency of defecation, lack of signs of anal incontinence and nocturnal defecation) were observed in 48/53 (90.6 %) patients. The quality of life was at a fairly high level in 90.6 % of patients.
Conclusion. The proposed method of FAP treatment allowed the immediate and long-term treatment results to be improved significantly.

Aim. This review aims to generalize data on the mutual aggravating effect on the course of gastroesophageal reflux disease (GERD) and coronary heart disease (CHD).
General findings. The combination of CHD and GERD is a common clinical situation. In recent years, more and more information has appeared indicating a non-accidental character of the comorbidity of both diseases. In addition to common risk factors, a number of pathophysiological mechanisms have been established that determine a pathogenetic relationship between CHD and GERD. Reflux disease contributes adversely to chronic coronary heart disease, e.g. by increasing the risk of developing myocardial infarction (MI). The co-occurrence of myocardial ischemia episodes (registered by ECG) with those of heartburn has been identified. A correlation between pathological reflux and ST segment depression has been found. A trigger role of reflux in relation to angina attacks and heart rhythm disturbances has been determined. The pro-arrhythmic effects of GERD on the myocardium are explained by an imbalance of the autonomic nervous system with a predominance of the parasympathetic tone. In turn, both stable angina and myocardial infarction contribute to a more aggressive and refractory course of reflux esophagitis (RE), thus triggering reflux symptoms.
Conclusion. The comorbid course of coronary heart disease and GERD is based on complex associations; this clinical situation is characterized by a mutual burden syndrome. Given the high prevalence of a combination of both diseases, it seems relevant to develop pathogenetically substantiated approaches to the management of this category of patients.

Aim. To present a clinical case with differential diagnosis of the cause of diarrhea in a patient with selective IgA deficiency.

Key findings. A 46-year-old woman complained of a mushy stool without pathological impurities up to 5 times a day. An outpatient colonoscopy revealed signs of terminal ileitis. The patient’s medical history included selective IgA and vitamin B12 deficiency. Despite the absence of antibodies to parietal cells and intrinsic factor, a diagnosis of autoimmune gastritis was established on the basis of histologically confirmed atrophy of the stomach; decrease in serum pepsinogen I and the ratio of pepsinogen I to pepsinogen II, hypergastrinemia; vitamin B12 deficiency; proven autoimmune thyroiditis (antibodies to thyroglobulin and thyroid peroxidase in the diagnostic titre). Histologically, lymphoid hyperplasia of the stomach was determined. Colonoscopy revealed erosive terminal ileitis and colitis, as well as an increase in the lymphoid follicles of the sub-mucosal layer in the ileum and all parts of the colon, which gave a rough pattern to the mucosa. Histological examination revealed pronounced follicular hyperplasia of the lymphoid tissue of the ileum and colon. The clinical diagnosis was established as follows. The combined main disease: 1. Selective IgA deficiency with a nodular lymphoid hyperplasia of the stomach, small and large intestine. 2. Autoimmune gastritis with erosions in the gastric fornix. Vitamin B12 deficiency. Concomitant diseases: Autoimmune thyroiditis.

Conclusion. The presented clinical observation demonstrates the importance of recognizing nodular lymphoid hyperplasia, which is established as the cause of diarrhea in a patient with selective IgA deficiency after excluding the diagnosis of Crohn’s disease. A specific feature of the presented clinical case is a combination of autoimmune gastritis and autoimmune thyroiditis with selective IgA deficiency.