Gut Microbiota and Biomarkers of Endothelial Dysfunction in Cirrhosis

Our aim was to study the association of endothelial dysfunction biomarkers with cirrhosis manifestations, bacterial translocation, and gut microbiota taxa. The fecal microbiome was assessed using 16S rRNA gene sequencing. Plasma levels of nitrite, big endothelin-1, asymmetric dimethylarginine (ADMA), presepsin, and claudin were measured as biomarkers of endothelial dysfunction, bacterial translocation, and intestinal barrier dysfunction. An echocardiography with simultaneous determination of blood pressure and heart rate was performed to evaluate hemodynamic parameters. Presepsin, claudin 3, nitrite, and ADMA levels were higher in cirrhosis patients than in controls. Elevated nitrite levels were associated with high levels of presepsin and claudin 3, the development of hemodynamic circulation, hypoalbuminemia, grade 2-3 ascites, overt hepatic encephalopathy, high mean pulmonary artery pressure, increased abundance of Proteobacteria and Erysipelatoclostridium, and decreased abundance of Oscillospiraceae, Subdoligranulum, Rikenellaceae, Acidaminococcaceae, Christensenellaceae, and Anaerovoracaceae. Elevated ADMA levels were associated with higher Child-Pugh scores, lower serum sodium levels, hypoalbuminemia, grade 2-3 ascites, milder esophageal varices, overt hepatic encephalopathy, lower mean pulmonary artery pressure, and low abundance of Erysipelotrichia and Erysipelatoclostridiaceae. High big endothelin-1 levels were associated with high levels of presepsin and sodium, low levels of fibrinogen and cholesterol, hypocoagulation, increased Bilophila and Coprobacillus abundances, and decreased Alloprevotella abundance.

Efficacy and Safety of a Probiotic Containing Saccharomyces boulardii CNCM I-745 in the Treatment of Small Intestinal Bacterial Overgrowth in Decompensated Cirrhosis: Randomized, Placebo-Controlled Study

(1) Background: The aim was to evaluate the effectiveness of the probiotic containing Saccharomyces boulardii in the treatment of small intestinal bacterial overgrowth (SIBO) in patients with decompensated cirrhosis. (2) Methods: This was a blinded, randomized, placebo-controlled study. (3) Results: After 3 months of treatment, SIBO was absent in 80.0% of patients in the probiotic group and in 23.1% of patients in the placebo group (p = 0.002). The patients with eliminated SIBO had decreased frequency of ascites and hepatic encephalopathy, the increased platelets and albumin levels, the decreased blood levels of total bilirubin, biomarkers of bacterial translocation (lipopolysaccharide [LPS]) and systemic inflammation (C-reactive protein), and positive changes in markers of hyperdynamic circulation compared with the state at inclusion. There were no significant changes in the claudin 3 level (the intestinal barrier biomarker) in these patients. No significant changes were observed in the group of patients with persistent SIBO. The serum level of nitrate (endothelial dysfunction biomarker) was lower in patients with eradicated SIBO than in patients with persistent SIBO. One (5.3%) patient with eradicated SIBO and six (42.9%) patients with persistent SIBO died within the first year of follow-up (p = 0.007). (4) Conclusions: SIBO eradication was an independent predictor of a favorable prognosis during the first year of follow-up.

Gut Microbiota and Bacterial Translocation in the Pathogenesis of Liver Fibrosis

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.

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.

Effect of Rebamipide on the Intestinal Barrier, Gut Microbiota Structure and Function, and Symptom Severity Associated with Irritable Bowel Syndrome and Functional Dyspepsia Overlap: A Randomized Controlled Trial

Treatment of functional digestive disorders is not always effective. Therefore, a search for new application points for potential drugs is perspective. Our aim is to evaluate the effect of rebamipide on symptom severity, intestinal barrier status, and intestinal microbiota composition and function in patients with diarrheal variant of irritable bowel syndrome overlapping with functional dyspepsia (D-IBSoFD). Sixty patients were randomized to receive trimebutine (TRI group), trimebutine + rebamipide (T + R group), or rebamipide (REB group) for 2 months. At the beginning and end of the study, patients were assessed for general health (SF-36), severity of digestive symptoms (Gastrointestinal Symptom Rating and 7 × 7 scales), state of the intestinal barrier, and composition (16S rRNA gene sequencing) and function (short-chain fatty acid fecal content) of the gut microbiota. The severity of most digestive symptoms was reduced in the REB and T + R groups to levels similar to that observed in the TRI group. The duodenal and sigmoidal lymphocytic and sigmoidal eosinophilic infiltration was decreased only in the REB and T + R groups, not in the TRI group. Serum zonulin levels were significantly decreased only in the REB group. A decrease in intraepithelial lymphocytic infiltration in the duodenum correlated with a decrease in the severity of rumbling and flatulence, while a decrease in infiltration within the sigmoid colon correlated with improved stool consistency and decreased severity of the sensation of incomplete bowel emptying. In conclusion, rebamipide improves the intestinal barrier condition and symptoms in D-IBSoFD. The rebamipide effects are not inferior to those of trimebutine.

Gut Dysbiosis and Hemodynamic Changes as Links of the Pathogenesis of Complications of Cirrhosis

The aim was to evaluate the relationship between gut dysbiosis and hemodynamic changes (hyperdynamic circulation) in cirrhosis, and between hemodynamic changes and complications of this disease. This study included 47 patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. Echocardiography with a simultaneous assessment of blood pressure and heart rate was performed to assess systemic hemodynamics. Patients with hyperdynamic circulation had more severe cirrhosis, lower albumin, sodium and prothrombin levels, higher C-reactive protein, aspartate aminotransferase and total bilirubin levels, and higher incidences of portopulmonary hypertension, ascites, overt hepatic encephalopathy, hypoalbuminemia, hypoprothrombinemia, systemic inflammation, and severe hyperbilirubinemia than patients with normodynamic circulation. Patients with hyperdynamic circulation compared with those with normodynamic circulation had increased abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Fusobacteria, Micrococcaceae, Intestinobacter, Clostridium sensu stricto, Proteus and Rumicoccus, and decreased abundance of Bacteroidetes, Bacteroidaceae, Holdemanella, and Butyrivibrio. The systemic vascular resistance and cardiac output values correlated with the abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Micrococcaceae, and Fusobacteria. Heart rate and cardiac output value were negatively correlated with the abundance of Bacteroidetes. The mean pulmonary artery pressure value was positively correlated with the abundance of Proteobacteria and Micrococcaceae, and negatively with the abundance of Holdemanella.

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.

Differences in Fecal Short-Chain Fatty Acids between Alcoholic Fatty Liver-Induced Cirrhosis and Non-alcoholic (Metabolic-Associated) Fatty Liver-Induced Cirrhosis

The objective of this study was to investigate the metabolic activity of the gut microbiota in cirrhosis due to different variants of fatty liver disease (alcoholic vs. non-alcoholic [metabolic-associated] one [AFLD and MAFLD]). The present study included 24 patients with alcoholic liver cirrhosis, 16 patients with MAFLD-related cirrhosis, and 20 healthy controls. The level and spectrum of short-chain fatty acids (SCFAs) were determined via gas-liquid chromatography. All patients with cirrhosis showed a decrease in the total content of SCFAs (p < 0.001) and absolute content of acetate (p < 0.001), propionate (p < 0.001), butyrate (p < 0.001), and isovalerate (p < 0.001). In MAFLD cirrhosis, the metabolic activity of the microbiota was significantly altered compared to patients with alcoholic cirrhosis, as evidenced by a lower total SCFA content (p < 0.001) and absolute content of acetate (p < 0.001), propionate (p < 0.001), and butyrate (p < 0.001); a higher relative content of isovalerate (p < 0.001); and a higher IsoCn/Cn ratio (p < 0.001). Various clinical and laboratory parameters correlate differently with fecal SCFAs and their fractions in cirrhosis due to AFLD and MAFLD. SCFA-producing metabolic activity is reduced more in MAFLD cirrhosis than in alcoholic cirrhosis. According to the etiological factors of cirrhosis, disorders of this metabolic activity may be involved in different pathogenetic pathways.

Epidemiology of small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) is defined as an increase in the bacterial content of the small intestine above normal values. The presence of SIBO is detected in 33.8% of patients with gastroenterological complaints who underwent a breath test, and is significantly associated with smoking, bloating, abdominal pain, and anemia. Proton pump inhibitor therapy is a significant risk factor for SIBO. The risk of SIBO increases with age and does not depend on gender or race. SIBO complicates the course of a number of diseases and may be of pathogenetic significance in the development of their symptoms. SIBO is significantly associated with functional dyspepsia, irritable bowel syndrome, functional abdominal bloating, functional constipation, functional diarrhea, short bowel syndrome, chronic intestinal pseudo-obstruction, lactase deficiency, diverticular and celiac diseases, ulcerative colitis, Crohn’s disease, cirrhosis, metabolic-associated fatty liver disease (MAFLD), primary biliary cholangitis, gastroparesis, pancreatitis, cystic fibrosis, gallstone disease, diabetes, hypothyroidism, hyperlipidemia, acromegaly, multiple sclerosis, autism, Parkinson’s disease, systemic sclerosis, spondylarthropathy, fibromyalgia, asthma, heart failure, and other diseases. The development of SIBO is often associated with a slowdown in orocecal transit time that decreases the normal clearance of bacteria from the small intestine. The slowdown of this transit may be due to motor dysfunction of the intestine in diseases of the gut, autonomic diabetic polyneuropathy, and portal hypertension, or a decrease in the motor-stimulating influence of thyroid hormones. In a number of diseases, including cirrhosis, MAFLD, diabetes, and pancreatitis, an association was found between disease severity and the presence of SIBO. Further work on the effect of SIBO eradication on the condition and prognosis of patients with various diseases is required.

Impact of vaccination against the novel coronavirus infection (COVID-19) with Sputnik V on mortality during the delta variant surge

OBJECTIVES

The aim is to study impact of vaccination against the novel coronavirus disease (COVID-19) with Sputnik V on mortality during the period of predominance of the delta variant of SARS-CoV-2.

METHODS

This was a retrospective cohort study of individuals with state health insurance at the Moscow Ambulatory Center. The cohorts included 41,444 persons vaccinated with Sputnik V, 15,566 survivors of COVID-19, and 71,377 non-immune persons. The deaths of patients that occurred from June 1, 2021, to August 31, 2021, were analyzed.

RESULTS

Overall (0.39 % vs. 1.92 %; p < 0.001), COVID-19-related (0.06 % vs. 0.83 %; p < 0.001), and non-COVID mortality (0.33 % vs. 1.09 %; p < 0.001) was lower among vaccinated individuals than among non-immune individuals. The efficacy of vaccination against death from COVID-19 was 96 % [95 % CI 91-98 %] in the general population, 100 % among those aged 18-50 years, 97 % [95 % CI 76-100 %] among those aged 51-70 years, 98 % [95 % CI 90-100 %] among those aged 71-85 years, and 88 % [95 % CI 49-97 %] among those aged > 85 years.

CONCLUSION

COVID-19 vaccination with Sputnik V is associated with a decrease in overall and COVID-19-related mortality and is not with increased non-COVID mortality.

Small Intestinal Bacterial Overgrowth Is Associated with Poor Prognosis in Cirrhosis

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is associated with numerous manifestations of cirrhosis. To determine whether the presence of SIBO affects the prognosis in cirrhosis was the aim of the study.

METHODS

This prospective cohort study included 50 patients. All participants underwent a lactulose hydrogen breath test for SIBO. The follow-up period was 4 years.

RESULTS

SIBO was detected in 26 (52.0%) patients: in 10 (52.6%) patients with compensated cirrhosis and in 16 (51.6%) ones with decompensated cirrhosis. Twelve (46.2%) patients with SIBO and four (16.7%) patients without SIBO died within 4 years (p = 0.009). Among patients with decompensated cirrhosis, 8 (50.0%) patients with SIBO and 3 (20.0%) patients without SIBO died (p = 0.027). Among patients with compensated cirrhosis, four (40.0%) patients with SIBO and one (11.1%) patient without SIBO died (p = 0.045). Among patients with SIBO, there was no difference in mortality between patients with compensated and decompensated cirrhosis (p = 0.209). It was the same for patients without SIBO (p = 0.215). SIBO affects the prognosis only in the first year of follow-up in decompensated cirrhosis, and only in subsequent years in compensated cirrhosis. Presence of SIBO (p = 0.028; HR = 4.2(1.2-14.9)) and serum albumin level (p = 0.027) were significant independent risk factors for death in cirrhosis.

CONCLUSIONS

SIBO is associated with poor prognosis in cirrhosis.

Eubiotic effect of rifaximin is associated with decreasing abdominal pain in symptomatic uncomplicated diverticular disease: results from an observational cohort study

BACKGROUND

Rifaximin effectively treats symptomatic uncomplicated diverticular disease (SUDD) and has shown eubiotic potential (i.e., an increase in resident microbial elements with potential beneficial effects) in other diseases. This study investigated changes in the fecal microbiome of patients with SUDD after repeated monthly treatment with rifaximin and the association of these changes with the severity of abdominal pain.

METHODS

This was a single-center, prospective, observational, uncontrolled cohort study. Patients received rifaximin 400 mg twice a day for 7 days per month for 6 months. Abdominal pain (assessed on a 4-point scale from 0 [no pain] to 3 [severe pain]) and fecal microbiome (assessed using 16 S rRNA gene sequencing) were assessed at inclusion (baseline) and 3 and 6 months. The Spearman's rank test analyzed the relationship between changes in the gut microbiome and the severity of abdominal pain. A p-value ≤ 0.05 was considered statistically significant.

RESULTS

Of the 23 patients enrolled, 12 patients completed the study and were included in the analysis. Baseline abdominal pain levels decreased significantly after 3 (p = 0.036) and 6 (p = 0.008) months of treatment with rifaximin. The abundance of Akkermansia in the fecal microbiome was significantly higher at 3 (p = 0.017) and 6 (p = 0.015) months versus baseline. The abundance of Ruminococcaceae (p = 0.034), Veillonellaceae (p = 0.028), and Dialister (p = 0.036) were significantly increased at 6 months versus baseline, whereas Anaerostipes (p = 0.049) was significantly decreased. The severity of abdominal pain was negatively correlated with the abundance of Akkermansia (r=-0.482; p = 0.003) and Ruminococcaceae (r=-0.371; p = 0.026) but not with Veillonellaceae, Dialister, or Anaerostipes. After 3 months of rifaximin, abdominal pain was significantly less in patients with Akkermansia in their fecal microbiome than in patients without Akkermansia (p = 0.022).

CONCLUSION

The eubiotic effect of rifaximin was associated with decreased abdominal pain in patients with SUDD.

Effect of probiotics on hemodynamic changes and complications associated with cirrhosis: A pilot randomized controlled trial

BACKGROUND

Bacterial translocation exacerbates the hyperdynamic circulation observed in cirrhosis and contributes to a more severe disease course. Probiotics may reduce bacterial translocation and may therefore be useful to redress the circulatory imbalance.

AIM

To investigate the effect of probiotics on hemodynamic parameters, systemic inflammation, and complications of cirrhosis in this randomized placebo-controlled trial.

METHODS

This single-blind randomized placebo-controlled study included 40 patients with Child-Pugh class B and C cirrhosis; 24 patients received probiotics (Saccharomyces boulardii) for 3 mo, and 16 patients received a placebo over the same period. Liver function and the systemic hemodynamic status were evaluated pre- and post-intervention. Echocardiography and simultaneous blood pressure and heart rate monitoring were performed to evaluate systemic hemodynamic indicators. Cardiac output and systemic vascular resistance were calculated.

RESULTS

Following a 3-mo course of probiotics in comparison to the control group, we observed amelioration of hyperdynamic circulation [a decrease in cardiac output (P = 0.026) and an increase in systemic vascular resistance (P = 0.026)] and systemic inflammation [a decrease in serum C-reactive protein levels (P = 0.044)], with improved liver function [an increase in serum albumin (P = 0.001) and a decrease in the value of Child-Pugh score (P = 0.001)] as well as a reduction in the severity of ascites (P = 0.022), hepatic encephalopathy (P = 0.048), and cholestasis [a decrease in serum alkaline phosphatase (P = 0.016) and serum gamma-glutamyl transpeptidase (P = 0.039) activity] and an increase in platelet counts (P < 0.001) and serum sodium level (P = 0.048).

CONCLUSION

Probiotic administration was associated with amelioration of hyperdynamic circulation and the associated complications of cirrhosis.

Gut dysbiosis and body composition in cirrhosis

BACKGROUND

Gut dysbiosis and changes in body composition (i.e., a decrease in the proportion of muscle mass and an increase in extracellular fluid) are common in cirrhosis.

AIM

To study the relationship between the gut microbiota and body composition in cirrhosis.

METHODS

This observational study included 46 patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. Multifrequency bioelectrical impedance analysis was performed to assess body composition in these patients.

RESULTS

An increase in fat mass and a decrease in body cell mass were noted in 23/46 (50.0%) and 15/46 (32.6%) patients, respectively. Changes in the gut microbiome were not independently associated with the fat mass percentage in cirrhosis. The abundance of Bacteroidaceae (P = 0.041) and Eggerthella (P = 0.001) increased, whereas that of Erysipelatoclostridiaceae (P = 0.006), Catenibacterium (P = 0.021), Coprococcus (P = 0.033), Desulfovibrio (P = 0.043), Intestinimonas (P = 0.028), and Senegalimassilia (P = 0.015) decreased in the gut microbiome of patients with body cell mass deficiency. The amount of extracellular fluid increased in 22/46 (47.6%) patients. Proteobacteria abundance (P < 0.001) increased, whereas Firmicutes (P = 0.023), Actinobacteria (P = 0.026), Bacilli (P = 0.008), Anaerovoraceceae (P = 0.027), Christensenellaceae (P = 0.038), Eggerthellaceae (P = 0.047), Erysipelatoclostridiaceae (P = 0.015), Erysipelotrichaceae (P = 0.003), Oscillospiraceae (P = 0.024), Rikenellaceae (P = 0.002), Collinsella (P = 0.030), Hungatella (P = 0.040), Peptococcaceae (P = 0.023), Slackia (P = 0.008), and Senegalimassilia (P = 0.024) abundance decreased in these patients. Patients with clinically significant ascites (n = 9) had a higher abundance of Proteobacteria (P = 0.031) and a lower abundance of Actinobacteria (P = 0.019) and Bacteroidetes (P = 0.046) than patients without clinically significant ascites (n = 37).

CONCLUSION

Changes in the amount of body cell mass and extracellular fluid are associated with changes in the gut microbiome in cirrhosis patients.

Probiotic Saccharomyces boulardii in the Treatment of Small Intestinal Bacterial Overgrowth in Decompensated Cirrhosis

Objectives

Small intestinal bacterial overgrowth (SIBO) is often detected in cirrhosis and is associated with the development of a number of its complications. Currently, there is no data on the effectiveness of drugs in the treatment of this disorder in this disease. The aim of the study was to evaluate the efficacy of probiotic Saccharomyces boulardii in the treatment of SIBO in cirrhosis.

Methods

This was a study in which 37 patients with decompensated cirrhosis and SIBO were randomized into 2 groups in a ratio of 1.5 to 1. The probiotic group included 24 patients who received probiotic Saccharomyces boulardii at a dose of 250 mg 2 times a day for 3 months in addition to standard therapy. The control group included 13 patients who received placebo for 3 months in addition to standard therapy. The use of antibiotics was prohibited. The patients were blinded. The presence of SIBO was assessed on the basis of a lactulose hydrogen breath test.

Results

The mean age of the included patients was 50.5 ± 9.9 years. There were 14 men and 23 women. Cirrhosis was alcoholic in 19 cases, viral in 5 cases, metabolic in 2 cases, mixed etiology in 7 cases, cryptogenic in 4 cases. After 3 months of probiotic or placebo use, SIBO was detected in 4 (16.7%) patients in the probiotic group and in 10 (76.9%) patients in the control group (P = 0.001). Moreover, the incidence of ascites in the probiotic group decreased from 83.3% to 45.8% (P = 0.007) and did not change significantly in the placebo group (69.2% vs. 84.6%; P = 0.007). No adverse effects of probiotics or placebo use were reported.

Conclusions

Probiotic Saccharomyces boulardii is effective and safe in the treatment of SIBO in decompensated cirrhosis.

Funding Sources

Supported by BIOCODEX MICROBIOTA FOUNDATION: National Research Grant Russia 2019.

Clostridioides difficile co-infection in patients with COVID-19

Aim: To assess the impact of Clostridioides difficile infection on the course of COVID-19. Methods: The authors included 809 patients with COVID-19 in this retrospective study: 55 had C. difficile infection, 23 had C. difficile-negative antibiotic-associated diarrhea and 731 had no diarrhea. C. difficile in feces was determined by immunochromatographic test for its toxins. Results:C. difficile infection was associated with increased risk of death (hazard ratio = 2.6; p = 0.021), especially after 20 days of disease (hazard ratio = 6.5; p < 0.001). C. difficile infection-associated diarrhea was longer and more severe than C. difficile-negative antibiotic-associated diarrhea. Unlike patients with C. difficile-negative antibiotic-associated diarrhea, patients with C. difficile infection were admitted to the intensive care unit and needed mechanical ventilation more often than those without diarrhea. Conclusion:C. difficile infection worsens the course and prognosis of COVID-19.

Epithelial protective therapy in comorbid diseases. Practical Guidelines for Physicians

In 2021 the first multidisciplinary National Consensus on the pathophysiological and clinical aspects of Increased Epithelial Permeability Syndrome was published. The proposed guidelines are developed on the basis of this Consensus, by the same team of experts. Twenty-eight Practical Guidelines for Physicians statements were adopted by the Expert Council using the "delphic" method. Such main groups of epithelial protective drugs as proton pump inhibitors, bismuth drugs and probiotics are discussed in these Guidelines from the positions of evidence-based medicine. The clinical and pharmacological characteristics of such a universal epithelial protector as rebamipide, acting at the preepithelial, epithelial and subepithelial levels, throughout gastrointestinal tract, are presented in detail.

Antibiotics, gut microbiota, and irritable bowel syndrome: What are the relations?

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder in which recurrent abdominal pain is associated with defecation or a change in bowel habits (constipation, diarrhea, or both), and it is often accompanied by symptoms of abdominal bloating and distension. IBS is an important health care issue because it negatively affects the quality of life of patients and places a considerable financial burden on health care systems. Despite extensive research, the etiology and underlying pathophysiology of IBS remain incompletely understood. Proposed mechanisms involved in its pathogenesis include increased intestinal permeability, changes in the immune system, visceral hypersensitivity, impaired gut motility, and emotional disorders. Recently, accumulating evidence has highlighted the important role of the gut microbiota in the development of IBS. Microbial dysbiosis within the gut is thought to contribute to all aspects of its multifactorial pathogenesis. The last few decades have also seen an increasing interest in the impact of antibiotics on the gut microbiota. Moreover, antibiotics have been suggested to play a role in the development of IBS. Extensive research has established that antibacterial therapy induces remarkable shifts in the bacterial community composition that are quite similar to those observed in IBS. This suggestion is further supported by data from cohort and case-control studies, indicating that antibiotic treatment is associated with an increased risk of IBS. This paper summarizes the main findings on this issue and contributes to a deeper understanding of the link between antibiotic use and the development of IBS.

Gut dysbiosis and small intestinal bacterial overgrowth as independent forms of gut microbiota disorders in cirrhosis

BACKGROUND

Gut dysbiosis and small intestinal bacterial overgrowth (SIBO) are commonly observed in patients with cirrhosis. Despite the substantial number of articles describing the relations between disorders of gut microbiota and various manifestations of cirrhosis, dysbiosis and SIBO were always studied separately.

AIM

To study the relationship of gut dysbiosis and SIBO in cirrhosis.

METHODS

This observational study included 47 in-patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. SIBO was assessed using the lactulose hydrogen breath test.

RESULTS

SIBO was found in 24/47 (51.1%) patients. Patients with SIBO had a higher abundance of Firmicutes (P = 0.017) and Fusobacteria (P = 0.011), and a lower abundance of Bacteroidetes (P = 0.013) than patients without SIBO. This increase in the abundance of Firmicutes occurred mainly due to an increase in the abundance of bacteria from the genus Blautia (P = 0.020) of the Lachnospiraceae family (P = 0.047), while the abundance of other major families of this phylum [Ruminococcaceae (P = 0.856), Peptostreptococcaceae (P = 0.066), Clostridiaceae (P = 0.463), Eubacteriaceae (P = 0.463), Lactobacillaceae (P = 0.413), and Veillonellaceae (P = 0.632)] did not differ significantly between the patients with and without SIBO. Reduced level of Bacteroidetes in samples from patients with SIBO was a result of the decrease in bacterial numbers from all the major families of this phylum [Bacteroidaceae (P = 0.014), Porphyromonadaceae (P = 0.002), and Rikenellaceae (P = 0.047)], with the exception of Prevotellaceae (P = 0.941). There were no significant differences in the abundance of taxa that were the main biomarkers of cirrhosis-associated gut dysbiosis [Proteobacteria (P = 0.790), Bacilli (P = 0.573), Enterobacteriaceae (P = 0.632), Streptococcaceae (P = 0.170), Staphylococcaceae (P = 0.450), and Enterococcaceae (P = 0.873)] between patients with and without SIBO.

CONCLUSION

Despite the differences observed in the gut microbiome between patients with and without SIBO, gut dysbiosis and SIBO are most likely independent disorders of gut microbiota in cirrhosis.

[Two consecutive attacks of diarrhea in 15 COVID-19 patients: An antibiotic-associated one following the viral one]

Of the 971 patients admitted to our Clinic with suspected COVID-19, 15 (1.5%) presented with two consecutive attacks of diarrhea. One of those patients (a 47-year-old woman) required admission to the intensive care unit and mechanical ventilation. She died on the 11th day of hospitalization (18th day of illness). The first attack of diarrhea in those patients occurred on the 6 th (4th-7th) day of disease and lasted 3 (3-5) days. The second attack of diarrhea developed 11 (8-12) days after the initial onset of diarrhea. Despite the existing trend, the difference in the duration of the diarrhea and the maximum number of bowel movements per day between the first and second attacks was not statistically significant (p = 0.130; p = 0.328). There was no significant difference between the patients with a double attack of diarrhea and those with no diarrhea, regarding the results of the complete blood count, biochemical blood tests, and inflammation biomarkers.

Two consecutive attacks of diarrhea in 15 COVID-19 patients: An antibiotic-associated one following the viral one

Of the 971 patients admitted to our Clinic with suspected COVID-19, 15 (1.5%) presented with two consecutive attacks of diarrhea. One of those patients (a 47-year-old woman) required admission to the intensive care unit and mechanical ventilation. She died on the 11th day of hospitalization (18th day of illness). The first attack of diarrhea in those patients occurred on the 6th (4th-7th) day of disease and lasted 3 (3-5) days. The second attack of diarrhea developed 11 (8-12) days after the initial onset of diarrhea. Despite the existing trend, the difference in the duration of the diarrhea and the maximum number of bowel movements per day between the first and second attacks was not statistically significant (p = 0.130; p = 0.328). There was no significant difference between the patients with a double attack of diarrhea and those with no diarrhea, regarding the results of the complete blood count, biochemical blood tests, and inflammation biomarkers.

Gut-liver axis in cirrhosis: Are hemodynamic changes a missing link?

Recent evidence suggests that the condition of the gut and its microbiota greatly influence the course of liver disease, especially cirrhosis. This introduces the concept of the gut–liver axis, which can be imagined as a chain connected by several links. Gut dysbiosis, small intestinal bacterial overgrowth, and intestinal barrier alteration lead to bacterial translocation, resulting in systemic inflammation. Systemic inflammation further causes vasodilation, arterial hypotension, and hyperdynamic circulation, leading to the aggravation of portal hypertension, which contributes to the development of complications of cirrhosis, resulting in a poorer prognosis. The majority of the data underlying this model were obtained initially from animal experiments, and most of these correlations were further reproduced in studies including patients with cirrhosis. However, despite the published data on the relationship of the disorders of the gut microbiota with the complications of cirrhosis and the proposed pathogenetic role of hemodynamic disorders in their development, the direct relations between gut dysbiosis and hemodynamic changes in this disease are poorly studied. They remain a missing link in the gut–liver axis and a challenge for future research.

Early viral versus late antibiotic-associated diarrhea in novel coronavirus infection

Diarrhea is one of the manifestations of the novel coronavirus disease (COVID-19), but it also develops as a complication of massive antibiotic therapy in this disease. This study aimed to compare these types of diarrhea.We included patients with COVID-19 in a cohort study and excluded patients with chronic diarrhea, laxative use, and those who died during the first day of hospitalization.There were 89 (9.3%), 161 (16.7%), and 731 (75.7%) patients with early viral, late antibiotic-associated, and without diarrhea, respectively. Late diarrhea lasted longer (6 [4-10] vs 5 [3-7] days, P < .001) and was more severe. Clostridioides difficile was found in 70.5% of tested patients with late diarrhea and in none with early diarrhea. Presence of late diarrhea was associated with an increased risk of death after 20 days of disease (P = .009; hazard ratio = 4.7). Patients with late diarrhea had a longer hospital stay and total disease duration, and a higher proportion of these patients required intensive care unit admission. Oral amoxicillin/clavulanate (odds ratio [OR] = 2.23), oral clarithromycin (OR = 3.79), and glucocorticoids (OR = 4.41) use was a risk factor for the development of late diarrhea, while ceftriaxone use (OR = 0.35) had a protective effect. Before the development of late diarrhea, decrease in C-reactive protein levels and increase in lymphocyte count stopped but the white blood cell and neutrophil count increased. An increase in neutrophils by >0.6 × 109 cells/L predicted the development of late diarrhea in the coming days (sensitivity 82.0%, specificity 70.8%, area under the curve = 0.791 [0.710-0.872]).Diarrhea in COVID-19 is heterogeneous, and different types of diarrhea require different management.

Efficacy of a Probiotic Consisting of Lacticaseibacillus rhamnosus PDV 1705, Bifidobacterium bifidum PDV 0903, Bifidobacterium longum subsp. infantis PDV 1911, and Bifidobacterium longum subsp. longum PDV 2301 in the Treatment of Hospitalized Patients with COVID-19: a Randomized Controlled Trial

The treatment of coronavirus disease (COVID-19) and COVID-19-associated diarrhea remains challenging. This study aimed to evaluate the efficacy of a multi-strain probiotic in the treatment of COVID-19. This was a randomized, controlled, single-center, open-label trial (NCT04854941). Inpatients with confirmed COVID-19 and pneumonia were randomly assigned to a group that received a multi-strain probiotic (PRO group) or to the control group (CON group). There were 99 and 101 patients in the PRO and CON groups, respectively. No significant differences in mortality, total duration of disease and hospital stay, incidence of intensive care unit admission, need for mechanical ventilation or oxygen support, liver injury development, and changes in inflammatory biomarker levels were observed between the PRO and CON groups among all included patients as well as among subgroups delineated based on age younger or older than 65 years, and subgroups with chronic cardiovascular diseases and diabetes. Diarrhea on admission was observed in 11.5% of patients; it resolved earlier in the PRO group than in the CON group (2 [1-4] vs. 4 [3-6] days; p = 0.049). Hospital-acquired diarrhea developed less frequently in the PRO group than in the CON group among patients who received a single antibiotic (0% vs. 12.5%; p = 0.023) unlike among those who received > 1 antibiotic (10.5% vs. 13.3%; p = 0.696). The studied probiotic had no significant effect on mortality and changes in most biomarkers in COVID-19. However, it was effective in treating diarrhea associated with COVID-19 and in preventing hospital-acquired diarrhea in patients who received a single antibiotic.

Probiotics in hepatology: An update

The gut–liver axis plays an important role in the pathogenesis of various liver diseases. Probiotics are living bacteria that may be used to correct disorders of this axis. Notable progress has been made in the study of probiotic drugs for the treatment of various liver diseases in the last decade. It has been proven that probiotics are useful for hepatic encephalopathy, but their effects on other symptoms and syndromes of cirrhosis are poorly studied. Their effectiveness in the treatment of metabolic associated fatty liver disease has been shown both in experimental models and in clinical trials, but their effect on the prognosis of this disease has not been described. The beneficial effects of probiotics in alcoholic liver disease have been shown in many experimental studies, but there are very few clinical trials to support these findings. The effects of probiotics on the course of other liver diseases are either poorly studied (such as primary sclerosing cholangitis, chronic hepatitis B and C, and autoimmune hepatitis) or not studied at all (such as primary biliary cholangitis, hepatitis A and E, Wilson's disease, hemochromatosis, storage diseases, and vascular liver diseases). Thus, despite the progress in the study of probiotics in hepatology over the past decade, there are many unexplored and unclear questions surrounding this topic.

Disruption of the pro-inflammatory, anti-inflammatory cytokines and tight junction proteins expression, associated with changes of the composition of the gut microbiota in patients with irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a pathologic condition characterized by changes in gut microbiome composition, low-grade inflammation, and disruption of intestinal wall permeability. The interaction between the gut microbiome and the disease manifestation remains unclear. The changing of tight junction proteins and cytokines expression throughout the gastrointestinal tract in IBS patients has not been studied yet.

AIM OF THE STUDY

To assess the changes of gut microbiome composition, tight junction proteins, and cytokines expression of intestinal mucosa from the duodenum to the distal part of the colon in IBS patients and healthy volunteers.

METHODS

In 31 IBS patients (16 patients with IBS-D; 15 patients with IBS-C) and 10 healthy volunteers the expression of CLD-2, CLD-3, CLD-5, IL-2, IL-10, and TNF-α in mucosal biopsy specimens was determined by morphological and immune-histochemical methods. The qualitative and quantitative composition of the intestinal microbiota was assessed based on 16S rRNA gene sequencing in both groups of patients.

RESULTS

The expression of IL-2 and TNF-α was significantly increased in IBS patients compared with the controls (p<0.001), with a gradual increase from the duodenum to the sigmoid colon. The expression of IL-10, CLD-3, and CLD-5 in mucosal biopsy specimens of these patients was lower than in the control group (p<0.001). Increased ratios of Bacteroidetes and decreased ratios of Firmicutes were noted in IBS patients compared to healthy volunteers (p<0.05).

CONCLUSION

IBS patients have impaired gut permeability and persisting low-grade inflammation throughout the gastrointestinal tract. Changes in the gut microbiota may support or exacerbate these changes.

Gut dysbiosis is associated with poorer long-term prognosis in cirrhosis

BACKGROUND

Gut dysbiosis is common in cirrhosis.

AIM

To study the influence of gut dysbiosis on prognosis in cirrhosis.

METHODS

The case-control study included 48 in-patients with cirrhosis and 21 healthy controls. Stool microbiome was assessed using 16S ribosomal ribonucleic acid gene sequencing. We used modified dysbiosis ratio (MDR): [Bacilli (%) + Proteobacteria (%)]/[Clostridia (%) + Bacteroidetes (%)]. Patients with MDR more the median made up the group with severe dysbiosis, others did the group with non-severe dysbiosis. The follow-up period was 4 years.

RESULTS

The mortality rate of patients with severe dysbiosis was significantly higher than that of patients with non-severe dysbiosis (54.2% vs 12.5%; P = 0.001). The presence of severe dysbiosis was independent risk factors for death [hazard ratio = 8.6 × (1.9-38.0); P = 0.005]. The abundance of Enterobacteriaceae (P = 0.002), Proteobacteria (P = 0.002), and Lactobacillaceae (P = 0.025) was increased and the abundance of Firmicutes (P = 0.025) and Clostridia (P = 0.045) was decreased in the deceased patients compared with the survivors. The deceased patients had a higher MDR value than the survivors [0.131 × (0.069-0.234) vs 0.034 × (0.009-0.096); P = 0.004]. If we applied an MDR value of 0.14 as the cutoff point, then it predicted patient death within the next year with a sensitivity of 71.4% and a specificity of 82.9% [area under the curve = 0.767 × (0.559-0.974)]. MDR was higher in patients with cirrhosis than in health controls [0.064 × (0.017-0.131) vs 0.005 × (0.002-0.007); P < 0.001], and in patients with decompensated cirrhosis than in patients with compensated cirrhosis [0.106 × (0.023-0.211) vs 0.033 × (0.012-0.074); P = 0.031]. MDR correlated negatively with prothrombin (r = -0.295; P = 0.042), cholinesterase (r = -0.466; P = 0.014) and serum albumin (r = -0.449; P = 0.001) level and positively with Child–Turcotte–Pugh scale value (r = 0.360; P = 0.012).

CONCLUSION

Gut dysbiosis is associated with a poorer long-term prognosis in cirrhosis.

Diarrhoea in adults with coronavirus disease-beyond incidence and mortality: a systematic review and meta-analysis

AIM

Diarrhoea is a relatively common manifestation of coronavirus disease (COVID-19), but there is no systematic review which comprehensively describes it beyond its incidence and impact on prognosis. This study aims to provide a detailed systematic review of diarrhoea in adults with COVID-19.

METHODS

A PUBMED and Scopus search (until 7 September 2020) was performed. Studies that were limited to describing incidence of diarrhoea and its effect on prognosis were excluded.

RESULTS

Twenty-six papers including 7860 patients with COVID-19 were subjected to synthesis. Mean duration of diarrhoea was 4.2 (3.6-4.9) days (range 1-16 days), whereas mean bowel movement count was 4.6 (3.8-5.3) and maximum was 20 per day. Diarrhoea started on an average 5.1 (3.8-6.5) days after disease onset but was the first manifestation in 4.3% patients. Stool occult blood was detected in 6.8% of patients with diarrhoea, while 53.3% cases had watery diarrhoea. Patients with diarrhoea also had elevated faecal calprotectin. Viral genome in faeces was detected more often in patients with diarrhoea and most often in patients without respiratory symptoms. Fever, myalgia and respiratory symptoms were observed with the same incidence in patients with and without diarrhoea. Similarly, there were no differences noted in complete blood count and most inflammation biomarkers between patients with and without diarrhoea. However, nausea, vomiting abdominal pain, sneezing and headache were more common in patients with diarrhoea. Diarrhoea was the main manifestation of COVID-19 in 6.1% of cases and this form of the disease had specific features.

CONCLUSIONS

Diarrhoea in COVID-19 needs further investigation.

Protective effects of Lactobacillus fermentum U-21 against paraquat-induced oxidative stress in Caenorhabditis elegans and mouse models

The aims of this work were to identify in vivo manifestations of antioxidant activity of Lactobacillus strains isolated from healthy human biotopes and to show the possibility of protective action of the selected strain on the model of oxidative stress induced by paraquat in the model of early Parkinson's disease (PD) in mice. We studied the protective effects of 14 Lactobacillus strains belonging to five species on the lifespan of the soil nematode Caenorhabditis elegans experiencing oxidative stress induced by paraquat. The Lactobacillus strains used in this study were selected previously based on their ability to reduce oxidative stress in vitro. One of the strains that showed promising results on C. elegans was tested in a mouse model of PD in which C57/BL6 mice were injected regularly with paraquat. We assessed the state of their internal organs, the preservation of dopaminergic neurons in the substantia nigra as well as their motor coordination. The positive impact of Lactobacillus fermentum U-21 strain supplementation on paraquat treated animals was observed. L. fermentum U-21 strain reduced the toxicity of paraquat in C. elegans model: the lifespan of the soil nematode C. elegans was extended by 25%. L. fermentum U-21 protected the mice against anatomical and behavioral changes typical of PD: there were no changes in the coordination of movement and the preservation of dopaminergic neurons in the brain. Life span of the nematode C. elegans pre-grown on a lawn of E. coli OP50 + Lactobacillus under oxidative stress conditions; the concentration of the oxidizing agent paraquat in the S medium was 50 mmol l^-1.

Clinical validation of the "7 × 7" questionnaire for patients with functional gastrointestinal disorders

BACKGROUND AND AIM

Physicians use different scales and questionnaires to assess the severity of clinical symptoms in patients with functional gastrointestinal disorders. The current study aimed to validate the "7 × 7" questionnaire for assessment of severity of the symptoms as a tool for the efficacy of treatment of functional gastrointestinal disorders, using the Clinical Global Impressions scale as the reference standard.

METHODS

Fifty inpatients aged from 18 to 64 with a confirmed diagnosis of irritable bowel syndrome (26 patients, 52%), functional dyspepsia (15 patients, 30%), or both (9 patients, 18%) were prospectively enrolled in the study. We used both the 7 × 7 questionnaire and the Clinical Global Impressions scale before and after 28 days of stable treatment.

RESULTS

Our study revealed a significant correlation between the 7 × 7 questionnaire and the Clinical Global Impressions scale results in assessment of severity of the clinical symptoms and their dynamics during treatment. The 7 × 7 questionnaire showed sensitivity of 74.5% and specificity of 54.1% for evaluating patients with mild to severe disease and 66.6% and 76%, respectively, for evaluating patients with moderate to severe disease. The Cronbach's alpha coefficient was 0.719. The intraclass correlation coefficient among participants in whom the condition remained the same was 0.973 (12 participants [24.5%]).

CONCLUSIONS

The 7 × 7 questionnaire is a convenient, sensitive, and reliable tool for assessing the severity of symptoms and treatment efficacy in people with functional gastrointestinal disorders.

A bioluminescent test system reveals valuable antioxidant properties of lactobacillus strains from human microbiota

Oxidative stress cause serious damages in human organism resulting in multiple diseases. Antioxidant therapy includes diet, the use of chemical agents or commensal bacteria such as lactobacilli. This study aims to evaluate the antioxidant (AO) activity of cell-free culture supernatants of lactobacilli, isolated from different parts of the human body. A test system based on Escherichia coli MG1655 strains carrying plasmids encoding luminescent biosensors pSoxS-lux and pKatG-lux inducible by superoxide anion and hydrogen peroxide, respectively, was used to analyze cell-free culture supernatants of lactobacilli. Bioluminescent detection systems are suitable for quick screening of AO activity of lactobacilli. The majority of strains (51 out of 81) belonging to six different species demonstrated various levels of antioxidant activity. This activity was confirmed using the trolox equivalent method. The genome of one of the strains showing high AO activity was sequenced, and the genes putatively involved in AO capacity were determined. Potencies of standard AO and CFS from the most active Lactobacillus strains. Percentages of decrease in the detected luminescence (IAO%) in the presence of AO or CFS are presented. L. br.-L. brevis, L. pl. -L. plantarum, L. rh.-L. rhamnosus.