Diagnosis and Treatment of Irritable Bowel Syndrome: Clinical Recommendations of the Russian Gastroenterological Association and Association of Coloproctologists of Russia

Small Intestinal Bacterial Overgrowth in Various Specialties of Medical Practice (Literature Review and Expert Council Resolution)

Aim: to discuss current views on the clinical significance, diagnostic opportunities, and therapeutic approaches in the treatment of small intestinal bacterial overgrowth (SIBO) as an important component in the gut microbiota function assessment, to assess the awareness of physicians and the opportunities in the diagnosis and treatment of this disease in patients in the Federal districts of the Russian Federation, as well as to present the proceedings of the Expert Council held on December 16, 2023 in Moscow.

Key points. SIBO is a common syndrome often associated with irritable bowel syndrome, liver cirrhosis, asthma, and congestive heart failure, being also a predictor of early death in the elderly. Today, in many regions of the Russian Federation, there are limitations for instrumental diagnosis of this disease — lack of awareness among doctors, unavailability of gas analyzers for diagnosing SIBO, lack of information about the need to diagnose SIBO in the standards of compulsory health insurance. Rifaximin is the first-line treatment due to the highest therapeutic efficacy. One of the ways to increase the efficacy of SIBO treatment is to include strain-specific probiotics in the treatment regimen. Saccharomyces boulardii CNCM I-745 is thought to be the most studied, promising probiotic. The review also presents statistical data on the issues in the diagnosis and treatment of SIBO in the regions of the Russian Federation.

Conclusion. Optimization of approaches to the diagnosis and treatment of SIBO, the development of domestic gas analyzers, increasing the awareness of physicians in all regions of the Russian Federation, as well as the development and optimization of clinical recommendations appear to be necessary measures to increase the effectiveness of medical care, the duration and quality of life of the Russian population. These goals can be achieved within the framework of Federal programs under the supervision of specialized reference centers of the Ministry of Health of the Russian Federation.

Intestinal Barrier and Gut Microbiota in Patients with Overlapping Irritable Bowel Syndrome and Functional Dyspepsia

BACKGROUND

Disturbances in the intestinal barrier and gut dysbiosis have been observed in patients with functional bowel diseases.

AIMS

To investigate the correlation between biomarkers of intestinal barrier disorders at different layers and the severity of symptoms in patients with overlapping diarrhea-predominant irritable bowel syndrome and functional dyspepsia (IDFO), as well as with gut microbiota taxa.

METHODS

This study included 45 patients with IDFO and 16 healthy controls. Endoscopy with biopsy of the duodenum and sigmoid colon (SC) was performed to count intraepithelial lymphocytes (IELs) and mucosal eosinophils (subepithelial layer), assess fatty acid binding protein (FABP; epithelial layer) level, and stain for mucin-2 (MUC-2; pre-epithelial layer). Composition of the gut microbiota was evaluated using 16S rRNA gene sequencing.

RESULTS

Patients with IDFO exhibited an increase in biomarkers of intestinal barrier disorders at all layers studied. IEL count in the duodenum was correlated with the severity of bloating (r = 0.336; p = 0.024) and, in the SC, was correlated with tenesmus severity (r = 0.303; p = 0.042). FABP-1 level in the SC was correlated with the severity of diarrhea (r = 0.577; p = 0.001), and FABP-5 concentration in the SC was correlated with abdominal distension (r = 0.477; p = 0.010). MUC-2 concentration in the duodenum was correlated with the severity of heartburn (r = 0.572; p = 0.025) and burning sensation in the epigastrium (r = 0.518; p = 0.048). All biomarkers of intestinal barrier permeability were correlated with the abundance of some gut microbiota taxa.

CONCLUSION

Patients with IDFO exhibited disrupted intestinal barrier function in all layers, which was associated with clinical symptom severity and changes in the gut microbiota.

Structure and Metabolic Activity of the Gut Microbiota in Diarrhea-Predominant Irritable Bowel Syndrome Combined with Functional Dyspepsia

Gut dysbiosis presents in many digestive diseases. The aim of this study is to investigate the composition of the gut microbiota and its metabolic activity in patients with diarrhea-predominant irritable bowel syndrome combined with functional dyspepsia (I + D). This study included 60 patients with I + D and 20 healthy controls. Gut microbiota composition was studied using 16S rRNA gene sequencing. The short-chain fatty acids (SCFAs) spectrum was determined via gas–liquid chromatography. Patients with I + D had an increase in the abundance of Holdemanella, Erysipelotrichaceae, Erysipelotrichales, Prevotellaceae, Agathobacter, Slackia, Lactococcus, Pseudomonadaceae, Stenotrophomonas, Xanthomonadaceae, Rhizobiaceae, Erysipelatoclostridiaceae, Lachnospiraceae, and other taxa in addition to a decrease in the abundance of Frisingicoccus, Ralstonia, Burkholderiaceae, Hungatella, Eisenbergiella, Parabacteroides, Peptostreptococcaceae, Merdibacter, Bilophila, Rikenellaceae, Tannerellaceae, Bacteroidaceae, and Flavonifractor in comparison to controls. Patients with I + D showed significantly higher total SCFA content in feces; increased absolute content of acetic acid, propionic acid, butyric acid, and isoacids; and a significant negative shift in the anaerobic index. The relative levels of the main SCFAs and isoacids in the patient group did not differ significantly from those in the control group. The fecal acetate and isoacid levels correlated with the severity of diarrhea. The fecal butyrate level correlated with the severity of flatulence.

Sarcopenia in cirrhosis: Prospects for therapy targeted to gut microbiota

Decreased muscle mass and function, also known as sarcopenia, is common in patients with cirrhosis and is associated with a poor prognosis. Although the pathogenesis of this disorder has not been fully elucidated, a disordered gut-muscle axis probably plays an important role. Decreased barrier function of the gut and liver, gut dysbiosis, and small intestinal bacterial overgrowth (SIBO) can lead to increased blood levels of ammonia, lipopolysaccharides, pro-inflammatory mediators, and myostatin. These factors have complex negative effects on muscle mass and function. Drug interventions that target the gut microbiota (long-term use of rifaximin, lactulose, lactitol, or probiotics) positively affect most links of the compromised gut-muscle axis in patients with cirrhosis by decreasing the levels of hyperammonemia, bacterial translocation, and systemic inflammation and correcting gut dysbiosis and SIBO. However, although these drugs are promising, they have not yet been investigated in randomized controlled trials specifically for the treatment and prevention of sarcopenia in patients with cirrhosis. No data exist on the effects of fecal transplantation on most links of gut-muscle axis in cirrhosis; however, the results of animal experimental studies are promising.

[Irritable bowel syndrome phenotypes: leading factors of genetics and epigenetics, mechanisms of formation]

AIM

To develop individualized approaches to the treatment of irritable bowel syndrome (IBS) based on the interaction of genetic and epigenetic factors, to characterize the phenotypes of the disease.

MATERIALS AND METHODS

According to the formulated concept of the authors, from the cohort of patients with IBS, subgroups were distinguished - "post-infectious IBS" (n=45), "IBS in overweight and obese people" (n=49), "comorbid IBS" (n=75) and "essential IBS" (n=51). In each subgroup the prevalence of candidate gene polymorphisms associated with IBS (COMT, SLC6A4, FTO), nutritional habits, levels of anxiety and depression, secretion of cortisol, serotonin, dopamine and zonulin levels in feces were studied.

RESULTS

Patients with "post-infectious IBS" are characterized by the carriage of the S allele of the SLC6A4 gene, the val/val genotype of the COMT gene, the prevalence of diarrhea, a high level of anxiety and frequent refusal of milk and dairy products. The phenotype "IBS in overweight and obese individuals" is characterized by L/L genotypes of the SLC6A4 gene, met/met of the COMT gene and A/A of the FTO gene, constipation, low plasma dopamine levels, signs of depression, frequent episodes of overeating, addiction to fatty and sweet foods, excessive consumption of sugar, lack of vegetables in the diet. The "comorbid IBS phenotype" is characterized by more frequent detection of the val/val genotype of the COMT gene and the carriage of the S allele of the SLC6A4 gene, clinically pronounced anxiety and depression, early onset of the disease, severe course, significant food restrictions and significant increase in epithelial permeability. With the "essential phenotype", there are no bright stigmas of the disease; it is not possible to identify distinctive genetic and epigenetic factors, as well as the leading pathogenetic mechanism.

CONCLUSION

The analysis of genetic and epigenetic factors, the leading mechanisms of the formation and course of IBS allows us to identify additional (except for "postinfectious") phenotypes of the disease: "IBS in overweight and obese people", "comorbid" and "essential".

Modern approach to the choice of laxative agent in surgical interventions in outpatient coloproctology

Introduction. Elimination of manifestations of functional constipation and normalization of the stool to date remain a complex and finally unresolved problem during typical surgical interventions in outpatient coloproctology.

Aim. To evaluate the clinical efficacy of the laxative agent sodium picosulfate in the surgical treatment of non-tumor diseases of the anal canal and rectum in outpatient settings.

Materials and methods. The results of surgical treatment of 566 patients with non-tumor diseases of the anal canal and rectum, which were divided into two groups, were analyzed. In 275 patients (group 1), laxative agents were not used during treatment or were used indiscriminately. In 291 patients (group 2), the laxative agent sodium picosulfate was used to normalize colon emptying and soften stools during treatment. Comparison criteria: level of pain syndrome after surgery, degree of inflammatory manifestations in the field of surgical intervention, shape, and nature of fecal masses (based on the Bristol scale), frequency of wound inflammatory complications and recovery time for patients.

Results. In the early stages after surgery, the stool had a softened consistency (type 5 and 6) in a much larger number of group 2 patients (89.7 ± 4.1 – 94.2 ± 5.1%) compared with group 1 patients (67.3 ± 4.8 – 76.7 ± 4.9%). At the same time, in group 2 patients, pain syndrome was less pronounced, inflammatory manifestations in the area of surgical intervention regressed faster, incidence of wound inflammatory complications decreased 2.8 times (from 16.4 to 5.8%) and work capacity was recovered earlier than in group 1 patients.

Conclusion. The use of the laxative agent sodium picosulfate in coloproctological patients when performing typical surgical interventions on the rectum and anal canal on an outpatient basis eliminates the manifestations of symptomatic constipation, ensures the formation of a softened stool in perioperative periods, reduces mechanical injury to the mucous membrane of the rectum by feces, reduces the level of pain syndrome, which improves the results of surgical treatment by reducing the number of wound inflammatory complications.

[Prevalence of combination of functional dyspepsia and irritable bowel syndrome: a meta-analysis of studies using the Rome III-IV Criteria]

AIM

To systematize data on the prevalence of the combination of functional dyspepsia (FD) and irritable bowel syndrome (IBS) using the Rome IIIIV Criteria.

MATERIALS AND METHODS

A search in electronic databases MEDLINE/PubMed, EMBASE, and Cochrane was conducted. The depth of search was 17 years (from January 2006 to May 2022). Original publications from peer-reviewed periodicals that applied the Rome IIIIV Criteria for diagnosis of FD and IBS in an adult patient population with detailed descriptive statistics to allow the resulting data to be included in the meta-analysis were selected for final analysis.

RESULTS

The final analysis included 38 studies involving 17,993 patients with FD and 15,883 patients with IBS. In the overall pool of studies using the Rome IIIIV Criteria, the pooled prevalence of FD in patients with IBS was 34.625% (95% confidence interval [CI] 28.15941.390), and the pooled prevalence of IBS in patients with FD was 37.549% (95% [CI] 31.51143.787). A random-effects model was used in the analyses since significant heterogeneity between results was found (p0.0001; I298%). Using the Rome III Criteria, the pooled prevalence of FD in patients with IBS was 31.993% (95% CI 26.13538.150; I2=98.17%), while the prevalence of IBS in patients with FD was 34.694% (95% [CI] 29.31940.273; I2=97,89%). An analysis of papers using the Rome IV Criteria demonstrated that the pooled prevalence of FD in patients with IBS was 42.614% (95% CI 18.58868.675; I2=98.97%), and the prevalence of IBS in patients with FD was 50.444% (95% CI 37.95662.904; I2=94,39%).

CONCLUSION

This meta-analysis demonstrated that the prevalence of the combination of FD and IBS identified using the Rome IIIIV Criteria is high and is reported in approximately 1 in 3 patients with the functional gastrointestinal disorders concerned. The prevalence of a combination of FD and IBS identified using the Rome IV Criteria is at least 10% higher than that using the Rome III Criteria.

Irritable bowel syndrome: current aspects of etiology, pathogenesis, clinic and treatment: A review

Among functional gastrointestinal disorders, Irritable bowel syndrome (IBS) rightfully continues to maintain its leading position. IBS is a kind of standard for understanding the pathogenetic essence of functional diseases of the digestive system, since it is the most common, studied and studied pathology. So, for the query "Irritable Bowel Syndrome" in the electronic database PubMed as of July 30, 2022, 16 599 sources were found, and for the query "Irritable Bowel Syndrome" in the scientific electronic library eLIBRARY.RU 6316. The first part of the review deals with topical aspects of the etiology, pathogenesis and clinical presentation of IBS. The urgency of the problem of IBS is associated with a significant decrease in the quality of life of patients. The review focuses on the role of psycho-emotional disorders, changes localized at the level of the intestinal wall; and a new coronavirus infection COVID-19 in the development of IBS. Abdominal pain as the leading manifestation of IBS is associated primarily with spasm. In this context, antispasmodic drugs can be considered not only as symptomatic agents, but also as pathogenetic therapy for IBS. In the second part of the review, the possibilities of one of the myotropic antispasmodics, mebeverine hydrochloride, in the treatment of IBS are considered in detail.

Clinical features and food preferences in persons with irritable bowel syndrome against the background of overweight and obesity

Aim. To identify the clinical features of the course and nutritional preferences of patients with irritable bowel syndrome (IBS) against the background of overweight and obesity in order to increase the effectiveness of therapy in this cohort of patients. Materials and methods. An open cohort cross-sectional study was conducted with the inclusion of 100 patients aged 18 to 44 years (mean age 30.636.37 years) with an established diagnosis of IBS. The main group included 50 overweight or obese people with IBS (mean age 31.675.99 years, BMI 31.314.16 kg/m2), among them: 16 men and 34 women. The comparison group included 50 people with normal weight (mean age 31.946.15 years, BMI 20.451.54 kg/m2), among them: 16 men and 34 women. IBS symptoms were assessed on a 10-point scale. Assessment of other gastroenterological complaints was carried out using a 4-point scale. The severity of anxiety and depression was assessed using the Hospital Anxiety and Depression Scale. The level of specific anxiety in relation to gastrointestinal symptoms was assessed using the VSI visceral sensitivity index. To assess the quality of life, a specific questionnaire for assessing the quality of life of patients with IBS IBS-QoL and a nonspecific questionnaire for assessing the quality of life SF-36 were used. Results. IBS patients who are overweight or obese are characterized by a more severe course of the disease, more frequent formation of a mixed variant of stool disorders and a tendency to constipation, a more common clinically pronounced anxiety and depression, a more pronounced abdominal pain syndrome and a low level of quality of life, and as well as specific food preferences. Conclusion. Studies are required to identify the relationship between the clinical features of the course of IBS and food preferences in overweight and obese individuals with leading pathogenetic mechanisms in order to correct the existing standard management regimens for overweight and obese patients suffering from IBS.

Determination of Probiotics Prescription Indications in Patients with Irritable Bowel Syndrome (Materials of the Expert Council and Literature Review)

Aim. To review the main indications for probiotics prescription in patients with irritable bowel syndrome and to present the materials of an Expert Council, which was held on 18 March 2022 in Moscow.

Key points. Gut microbiota disturbance is an integral part of irritable bowel syndrome (IBS) pathogenesis. Changes of colonic microbiota composition are associated with its functional potential modification, which leads to an increasing of the pro-inflammatory immune response, as well as to an exacerbation of the disease symptoms and quality of life decreasing in patients with IBS. The novel coronavirus infection (COVID-19) is an independent risk factor for both exacerbation and onset of IBS, which predispose to increase IBS incidence. Correction of gut microbiota composition with probiotics seems to be a promising therapeutic target for IBS treatment optimizing. The optimal probiotic should be effective, safe, strain-specific, and its dose and duration of administration should be confirmed by the results of clinical studies. Some of the probiotics with proven efficacy in IBS are Alflorex® and Enterol®.

Conclusion. Prescription of certain probiotics in IBS is advisable to normalize the frequency and consistency of stools, relieve abdominal pain and bloating, as well as improve patients’ quality of life.

Functional gastrointestinal diseases: mechanisms of development and principles of multitarget therapy

Currently, functional dyspepsia (FD) and irritable bowel syndrome (IBS) are among the most common nosological  units in the structure of functional gastrointestinal  diseases in adults. An important problem of treatment of these diseases at the current stage of medicine is low efficiency of monotarget drugs, which is determined by multicomponent pathogenesis. Indeed, the currently available  methods of drug treatment of FD and IBS have suboptimal  efficacy, as illustrated  by recent meta-analyses demonstrating high rates of NNT (the average number of patients who need to be treated to achieve a certain favorable outcome). In addition, the frequent “overlap” of these diseases forces clinicians to prescribe several drugs with different pharmacological actions to the patient, which inevitably leads to a decrease in compliance. The optimal strategy for managing patients with FD and IBS is the tactics of multitarget drugs that act on several links in the pathogenesis of these pathologies and have a significant evidence base in the effectiveness and safety of use. STW 5 (Iberogast®), included  in the clinical  guidelines  of the Russian Gastroenterological Association on the diagnosis and treatment of patients with FD, published in 2017, has the above-mentioned characteristics, as well as the clinical guidelines of the Russian Gastroenterological Association in collaboration with the Russian Association of Coloproctologists on the diagnosis and treatment of IBS, published in 2021. The clinical effectiveness of Iberogast in the treatment of FD and IBS has been demonstrated in a number of randomized trials, the results of which showed high efficacy of the drug and its good tolerability.