Small intestinal bacterial overgrowth in cirrhosis: systematic review and meta-analysis

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) was detected in cirrhosis in many studies. The aim is to perform a systematic review and meta-analysis on the prevalence of SIBO in cirrhosis and on the relationship of SIBO with features of cirrhosis.

METHODS

PUBMED search (until 14 January 2018) was performed. Specific search terms were: '(cirrhosis) AND (SIBO OR bacterial overgrowth)'. Studies not relating to cirrhosis or SIBO, animal studies, and non-original articles were excluded. A meta-analysis of all studies was performed using a random-effects model.

RESULTS

117 references were identified by the PUBMED search. 3 references were added after handsearching the reference lists of all the articles. 99 references were excluded. 21 studies (included in total 1264 cirrhotics and 306 controls) remained for qualitative analysis and quantitative synthesis. Prevalence of SIBO for cirrhosis was 40.8% (95% CI 34.8-47.1), while the prevalence of SIBO for controls was 10.7% (95% CI 5.7-19.0). OR 6.83 (95% CI 4.16-11.21; p < 0.001). Prevalence of SIBO for decompensated cirrhosis was higher than prevalence of SIBO for compensated cirrhosis (50.5% vs. 31.2%; p < 0.001). SIBO in cirrhosis was associated with ascites (p < 0.001), minimal hepatic encephalopathy (p = 0.001), bacterial translocation (p = 0.026), spontaneous bacterial peritonitis (p = 0.008), prolonged orocecal transit time (p < 0.001), and was not associated with hypocoagulation. Further studies are required to clarify the relationship of SIBO with hyperbilirubinemia, hypoalbuminemia, overt hepatic encephalopathy in past, esophageal varices and systemic inflammation.

CONCLUSION

Small intestinal bacterial overgrowth is more often detected in cirrhosis than in healthy persons and is associated with some features of cirrhosis.

Tofacitinib reduces mortality in coronavirus disease 2019 Tofacitinib in COVID-19

BACKGROUND AND AIM

Cytokine release syndrome is a dangerous complication of the coronavirus disease 2019 (COVID-19). This study aimed to evaluate the efficacy and safety of tofacitinib in the management of this complication.

METHODS

The retrospective study included COVID-19 patients with C-reactive protein (CRP) levels of 60-150 mg/L.

RESULTS

Thirty-two patients who received tofacitinib (TOF group) and 30 patients who did not receive any anti-cytokine drugs (control [CON] group) were enrolled. Mortality and the incidence of admission to the intensive care unit were lower in the TOF group than in the CON group (16.6% vs. 40.0%, p = 0.009; and 15.6% vs. 50.0%, p = 0.004). There was a significant decrease in the volume of the affected part of the lungs (p = 0.022) and a significant increase in oxygen saturation (p = 0.012) in the TOF group than in the CON group 7-10 days after the beginning tofacitinib administration. CRP level was lower in the TOF group than in the CON group (7 [3-22] vs. 20 [5-52] mg/L; p = 0.048) 7-10 days after the start of the administration of tofacitinib. During this period, the number of patients requiring mechanical ventilation or those in the prone position increased in the CON group compared to those in the TOF group (26.7% vs. 0.0%, p = 0.002; 33.3% vs. 6.7%, p = 0.020). There was no significant difference in the development of secondary infections, liver or kidney injury, and cytopenia between the two groups.

CONCLUSION

Tofacitinib was effective and safe for managing the cytokine release syndrome in COVID-19. Randomized controlled double-blind trials with tofacitinib with and without the simultaneous use of glucocorticoids are required to confirm our findings.

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.

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.

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.

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.

Is small intestinal bacterial overgrowth a cause of hyperdynamic circulation in cirrhosis?

BACKGROUND/AIMS

Small intestinal bacterial overgrowth (SIBO) and hemodynamic changes are common in cirrhosis. We wanted to examine our hypothesis whether SIBO leads to hemodynamic changes in cirrhosis.

MATERIALS AND METHODS

A total of 50 patients with cirrhosis and 15 healthy controls were enrolled in a pilot prospective study. All participants underwent the lactulose hydrogen breath test for SIBO and echocardiography with a simultaneous assessment of blood pressure and heart rate. Cardiac output and systemic vascular resistance were calculated.

RESULTS

Study participants with SIBO had a lower systolic blood pressure and systemic vascular resistance compared to those without SIBO and to healthy controls (110.2±12.3 mmHg vs. 126.2±21.0 mmHg and 121.2±9.8 mmHg; p=0.005 and p=0.011, respectively; 1312±352 dyn•s•cm-5 vs. 1704±424 dyn•s•cm-5 and 1648±272 dyn•s•cm-5; p=0.001 and p=0.006, respectively), but a higher cardiac output (5.38±1.41 l/min vs. 4.52±1.03 l/min and 4.40±0.68 l/min; p=0.034 and p=0.041, respectively) and C-reactive protein (10.5[1.2-16.5] mg/l vs. 2.8[0.6-9.1] mg/l; p=0.028; no comparison with healthy controls). There were no significant differences between patients without SIBO and healthy controls with regard to systolic blood pressure (p=0.554), systemic vascular resistance (p=0.874), and cardiac output (p=0.795). SIBO was associated with vasodilation and hyperdynamic circulation in decompensated cirrhosis (p=0.002; p=0.012), but not in compensated cirrhosis (p=1.000; p=0.474).

CONCLUSIONS

SIBO is associated with hyperdynamic circulation and other hemodynamic changes in cirrhosis and may be a principal factor causing these through systemic inflammation.

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.

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.

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.

Interleukin 17 antagonist netakimab is effective and safe in the new coronavirus infection (COVID-19)

Cytokine release syndrome is a serious complication of the new coronavirus infection (COVID-19). The aim of the study was to assess effectiveness and safety of the IL-17 antagonist nekatimab for its treatment. The retrospective study included COVID-19 patients with C-reactive protein levels >60 mg/L. Patients received either netakimab (group NET), IL-6 antagonist tocilizumab (group TOC) or no anti-cytokine treatment (group CON). Forty-four patients were enrolled in the NET group, 27 patients in the TOC group, and 47 patients in the CON group. Mortality was lower in the NET group than in TOC and CON groups (2.3% vs. 14.8% and 31.9%; p = 0.018 and p < 0.001). NET group patients required intensive care unit admission (6.8% vs. 25.9% and 46.3%; p = 0.025 and p < 0.001) and mechanical ventilation (4.6% vs. 22.2% and 31.9%; p = 0.022 and p = 0.002) less frequently than patients of the TOC and CON groups. After 7-10 days of anti-cytokine drug administration, a reduction in lung lesion volume (p = 0.016) and an increase in the proportion of patients who did not need oxygen support (p = 0.005) or stayed in prone position (p = 0.044) was observed in the NET group only group; C-reactive protein levels were the same in the TOC and NET groups (p = 0.136) and lower in the CON group (p < 0.001 and p = 0.005). IL-6 levels decreased in the NET group (p = 0.005) and did not change in the TOC group (p = 0.953). There was no difference in the incidence of side effects between groups. The IL-17 antagonist netakimab is effective and safe in the treatment of cytokine release syndrome in COVID-19.

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.

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.

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.

Immune disorders and rheumatologic manifestations of viral hepatitis

Infection with hepatotropic viruses is not limited to the liver and can lead to the development of various immunological disorders (the formation of cryoglobulins, rheumatoid factor, antinuclear antibodies, autoantibodies specific for autoimmune hepatitis and primary biliary cholangitis, and others), which can manifest as glomerulonephritis, arthritis, uveitis, vasculitis (cryoglobulinemic vasculitis, polyarteritis nodosa, Henoch-Schonlein purpura, isolated cutaneous necrotizing vasculitis), and other rheumatologic disorders, and be a trigger for the subsequent development of autoimmune hepatitis and primary biliary cholangitis. A further study of the association between autoimmune liver diseases and hepatotropic virus infection would be useful to assess the results of treatment of these associated diseases with antiviral drugs. The relationship of these immune disorders and their manifestations with hepatotropic viruses is best studied for chronic hepatitis B and C. Only isolated cases of these associations are described for hepatitis A. These links are least studied, and are often controversial for hepatitis E, possibly due to their relatively rare diagnoses. Patients with uveitis, glomerulonephritis, arthritis, vasculitis, autoimmune liver diseases should be tested for biomarkers of viral hepatitis, and if present, these patients should be treated with antiviral drugs.

Low Short-Chain-Fatty-Acid-Producing Activity of the Gut Microbiota Is Associated with Hypercholesterolemia and Liver Fibrosis in Patients with Metabolic-Associated (Non-Alcoholic) Fatty Liver Disease

The aim of this study was to investigate the short-chain fatty acid (SCFA) activity of the gut microbiota of patients with metabolic-associated fatty liver disease (MAFLD). The level and spectrum of short-chain fatty acids (SCFAs) were determined via gas–liquid chromatography. Liver fibrosis was assessed using the FIB-4 index and elastography. Among 42 non-cirrhotic MAFLD patients, 24 had high fecal SCFA levels (group H) and 18 had low fecal SCFA levels (group L). Patients in group H had lower serum uric acid, total cholesterol, and LDL cholesterol levels but a higher BMI than those in group L. All patients in group L and only 37.9% of those in group H were found to have hypercholesterolemia. In patients with hypercholesterolemia, the level of SCFAs was lower than that in patients without hypercholesterolemia. Patients in group H had less liver fibrosis than patients in group L. A total of 50.0% of the patients in group H and 92.3% of those in group L had significant liver fibrosis (≥F2). Patients with significant liver fibrosis had lower levels of fecal SCFAs—particularly acetate and butyrate. The fecal SCFA levels were positively correlated with gamma-glutamyl transferase, total bilirubin levels, BMI, and platelet count and were negatively correlated with FIB-4, liver stiffness, serum total, and LDL cholesterol levels.

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.

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.

Practical Recommendation of the Scientific Сommunity for Human Microbiome Research (CHMR) and the Russian Gastroenterological Association (RGA) on Small Intestinal Bacterial Overgrowth in Adults

Aim. To optimize the choice of treatment strategies by physicians and gastroenterologists to improve treatment and prevention of small intestinal bacterial overgrowth (SIBO) in adults.

Key points. SIBO is a condition characterized by an increased amount and/or abnormal composition of the microbiota in the small intestine. Clinically, the syndrome is manifested by nonspecific gastroenterological complaints and the development of malabsorption syndrome. Most often, SIBO is associated with various chronic non- infectious diseases (both diseases of the gastrointestinal tract, and the cardiovascular system and the neuromuscular apparatus) and can affect the severity of their symptoms. Specific methods for diagnosing SIBO are the culture method and breath tests. The main approaches to the treatment of SIBO include the elimination of the underlying cause of its occurrence, the use of antibacterial drugs and adherence to dietary recommendations (elemental diet).

Conclusion. Small intestinal bacterial overgrowth is common in patients with various diseases, but has non-specific manifestations, so proper diagnosis of this condition is required. SIBO therapy involves prescription of antibacterial agents, the most studied of which is the non-absorbable antibiotic rifaximin-α.

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.

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.

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.

Practical Recommendations of Scientific Society for the Study of Human Microbiome and Russian Gastroenterological Association (RGA) for Probiotics in Treatment and Prevention of Gastroenterological Diseases in Adults

Aim. To provide practical recommendations on the use of probiotics for the treatment and prevention of gastroenterological diseases in adults.

General provisions. Probiotics are living microorganisms that benefit the health of the host when administered in adequate amounts. The main functions of probiotics include the support for colonisation resistance, the metabolism of food substrates and utilisation of end metabolites, the production of substrates necessary for the macro-organism, as well as the regulation of local and adaptive immune responses. Probiotics can be registered in the Russian Federation as biologically active food additives (BAFA) or as pharmaceutical products (drugs) in accordance with the microbiological standards and legislative requirements of the Russian Federation. The probiotics registered in the Russian Federation as BAFA for adults include bacteria of the Lactobacillus, Bifidobacterium, Enterococcus, Pediococcus, Lactococcus, Streptococcus, Bacillus, and Escherichia genera, and fungi of the Saccharomyces genus; probiotics registered as drugs — bacteria of Lactobid, Lactobacid, Escherichia and Enterococcus genera and fungi of the Saccharomyces genus. Some probiotics registered in the Russian Federation include probiotic strains that have proved to be effective for the prevention and treatment of antibiotic-associated diarrhea, the prevention of C. difficile-associated disease, the eradication of H. pylori infection, as well as for the treatment of irritable bowel syndrome and functional constipation.

Conclusions. The clinical efficacy of probiotics depends on the probiotic strains included in their composition and is confirmed by a comparative analysis of the results of appropriate clinical studies. Not all probiotics registered in the Russian Federation as BAFA or drugs contain bacterial or fungal strains; as a result, the expected clinical effect may not be achieved.

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.