Minimal Hepatic Encephalopathy: Effect of H. pylori infection and small intestinal bacterial overgrowth treatment on clinical outcomes

Clinical study of probiotics combined with lactulose for minimal hepatic encephalopathy treatment

OBJECTIVE

This study aimed to investigate the clinical effect of probiotics combined with lactulose for minimal hepatic encephalopathy (MHE) treatment.

METHODS

A total of 88 patients with MHE were randomly divided into the control ( n  = 44) and combined groups ( n  = 44). The control group was treated with lactulose, while the combined group was treated with probiotics and lactulose. Serum ammonia, liver function [alanine aminotransferase (ALT) and aspartate transaminase (AST)], intestinal mucosal barrier markers [fatty acid-binding protein 2 (FABP2) and advanced glycation end-products (AGEs)] and number connection test A (NCT-A) and digit symbol test (DST) scores were tested and compared between the two groups.

RESULTS

The post-treatment in the control and combined groups shows decreased serum ammonia levels, ALT and AST levels, FABP2 and AGEs levels and NCT-A score and increased DST score compared with pre-treatment, with a significant difference ( P  < 0.05). Post-treatment, the serum ammonia level, ALT and AST levels, FABP2 and AGEs levels, NCT-A score decreased and DST score increased in the combined group compared with the control group, with a significant difference ( P  < 0.05).

CONCLUSION

Probiotics can promote lactulose in MHE treatment.

The Prevalence of Small Intestinal Bacterial Overgrowth in Patients with Non-Alcoholic Liver Diseases: NAFLD, NASH, Fibrosis, Cirrhosis-A Systematic Review, Meta-Analysis and Meta-Regression

Bacterial overgrowth in the small intestine (SIBO) is a pathological growth of the intestinal microbiota in the small intestine that causes clinical symptoms and can lead to digestive and absorption disorders. There is increasing evidence that people with NAFLD have a distinct gut microflora profile as well metabolome changes compared to people without NAFLD. Thorough analysis of observational and RCT studies in the current databases (EMBASE, Web of Science, PubMed, Cinahl, Clinical Trials) was conducted from 3 November 2021 to 21 June 2022. The following inclusion criteria were applied: confirmed NAFLD, NASH, LIVER FIBROSIS, CIRRHOSIS due to steatosis; diagnostic methods of liver diseases—biopsy, elastography, transabdominal ultrasound; nonalcoholic fatty liver disease activity score; confirmed SIBO; diagnostic methods of SIBO−breath tests (hydrogen test; methane test and mix test; duodenal and jejunal aspiration before any type of intervention; adults above 18yo; number of participants ≥20; full articles. We excluded review articles, populations with HBV/HCV infection and alcohol etiology and interventions that may affect NAFLD or SIBO treatment. The quality of each study methodology was classified by means of the Cochrane Collaboration’s tool (RCT) and Newcastle—Ottawa Quality Assessment Scale adapted for cross-sectional, cohort and case-control studies. The random effects meta-analysis of outcomes for which ≥2 studies contributed data was conducted. The I2 index to measure heterogeneity and the χ2 test of homogeneity (statistically significant heterogeneity p < 0.05) were applied. For categorical outcome, the pooled event rate (effect size) was calculated. This systematic review was reported according to PRISMA reporting guidelines. We initially identified 6643 studies, from which 18 studies were included in final meta-analysis. The total number of patients was 1263. Accepted SIBO diagnostic methods were both available breath tests (n-total = 15) and aspirate culture (n-total = 3). We found that among patients with non-alcoholic liver diseases, the random overall event rate of SIBO was 0.350 (95% CI, 0.244−0.472), p = 0.017. The subgroup analysis regarding a type of diagnosis revealed that the lowest ER was among patients who developed simultaneously NAFLD, NASH and fibrosis: 0.197 (95% CI, 0.054−0.510) as compared to other annotated subgroups. The highest prevalence of SIBO was observed in the NASH subgroup: 0.411 (95% CI, 0.219−0.634). There were no statistically significant differences in the prevalence of SIBO in different subgroups (p = 0.854). Statistically significant heterogeneity between studies was estimated (I2 = 86.17%, p = 0.00). Egger’s test did not indicate a publication bias (df = 16, p = 0.885). A meta-regression using a random-effects model revealed that higher percentage of males in the population with liver diseases is a predisposing factor toward SIBO (Q = 4.11, df = 1, p = 0.0426 with coefficient = 0.0195, SE = 0.0096, Z = 2.03). We showed that the prevalence of SIBO in patients with chronic non-alcoholic liver diseases can be as high as 35%, and it increases with the percentage of men in the population. The prevalence of SIBO does not differ significantly depending on the type of chronic liver disease. Despite the high heterogeneity and moderate and low quality of included studies, our meta-analysis suggests the existence of a problem of SIBO in the population of patients with non-alcoholic liver diseases, and the presence of SIBO, in turn, determines the therapeutic treatment of such type of patients, which indicates the need for further research in this area. The study protocol was registered with the international Prospective Register of Systematic Reviews (PROSPERO ID: CRD42022341473).

Hepatic Encephalopathy in Cirrhotic Patients and Risk of Small Intestinal Bacterial Overgrowth: A Systematic Review and Meta-Analysis

Background

Hepatic encephalopathy (HE) is a neurological and psychiatric syndrome. Recent evidence suggests that HE is not only a disease of the liver and brain but is also related to the gut. Small intestinal bacterial overgrowth (SIBO) is well known to be associated with cirrhosis, but the relationship between SIBO and HE is unclear. We conducted this comprehensive systematic review and meta-analysis to determine the association between SIBO and HE in cirrhotic patients.

Methods

We conducted a comprehensive literature search of all studies on the association of SIBO and HE in cirrhotic patients using the PubMed and Embase electronic databases. Studies were screened, and relevant data were extracted and analysed. We calculated the number of cases of SIBO in patients with HE and controls. We then compared the prevalence of SIBO between the two groups to calculate the odds ratios (ORs) and 95% confidence intervals (CIs). Funnel plots were constructed to identify potential publication bias.

Results

Six studies with 414 participants (219 HE patients and 195 controls) met the inclusion criteria. The prevalence of SIBO in cirrhotic patients with HE was significantly higher than that in those without HE. The combined OR was 4.43 (95% CI 1.73-11.32, P = 0.002). The heterogeneity was moderate (I² = 66%), and the funnel plot suggested no significant publication bias. Subgroup analysis showed that the OR was 1.95 (95% CI 0.63–6.09) in studies using the lactulose breath test (LBT) and 7.60 (95% CI 3.50–16.50) in studies using the glucose breath test (GBT). The prevalence of SIBO in cirrhotic patients was also related to the severity of liver disease.

Conclusions

Our meta-analysis identified a strong association between SIBO and HE, and the risk of SIBO was 4.43 times higher among cirrhotic patients with HE than among those without HE. SIBO could be a predisposing factor for the development of HE in cirrhotic patients. Therefore, the importance of SIBO should be emphasized in patients with HE.

A meta-analysis of the association between Helicobacter pylori infection and risk of hepatic encephalopathy

BACKGROUND

Although the association between Helicobacter pylori (H. pylori) infection and hepatic encephalopathy (HE) has been confirmed through some research, the results of these relevant studies still remain controversial. We conducted an updated meta-analysis based on published studies to address this issue.

METHODS

A systematic search was conducted, reviewing all studies about the association between H. pylori infection and HE, through November 2021. The outcome measures were presented as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

In total, 13 studies provided data from 2784 subjects. H. pylori infection increased the risk of HE by 32% (OR = 2.32, 95% CI: 1.78-3.04). The effect became greater after hepatic encephalopathy was divided into overt HE and minimal hepatic encephalopathy (MHE) (HE OR = 2.66, 95% CI: 2.01-3.51, MHE OR = 1.74, 95% CI: 1.10-2.76). After H. pylori eradication, the risk of HE was reduced by 64%.

CONCLUSIONS

H. pylori infection is significantly associated with HE, and the infection rate of H. pylori also increases with the severity of HE. Eradication of H. pylori has a protective effect on HE. Therefore, it is necessary to eradicate H. pylori in HE treatments.

Helicobacter pylori infection and small intestinal bacterial overgrowth–more than what meets the eye

Helicobacter pylori (H. pylori) infection is very common and affects a significant proportion of the world population. In contrast, the prevalence of small intestinal bacterial overgrowth (SIBO) in the general population is not well understood. There can be coexistence of both disease states in a given patient and their clinical symptoms may also overlap with one and another. There is no clear clinical guidelines for testing for and treating SIBO in patients with H. pylori infection. This review article explores the available evidence on the relationship between H. pylori infection and SIBO, diagnosis and treatment of these entities and also comments on associated non-gastrointestinal conditions.

Efficacy of rifaximin in treating with small intestine bacterial overgrowth: a systematic review and meta-analysis

OBJECTIVES

Over the past decades, rifaximin has been used to treat with small intestinal bacterial overgrowth (SIBO), however, the true efficacy remains unknown. This systematic review and meta-analysis was performed to assess the safety and efficacy of rifaximin in treating with patients with SIBO.

METHODS

Embase, Pubmed, Cochrane Central Register of Controlled Trials, and Web of Science were searched from inception to April, 2021 for published randomized controlled trials (RCTs) and observational studies with or without comparable arms.

RESULTS

A total of 21 observational studies and 5 RCTs involving 874 patients were included. The overall eradication rate according to intention-to-treat analysis (ITT) was 59% (95% CI: 50 to 69%; I² = 90.69%) and to per protocol analysis (PP) 63% (95% CI: 53 to 72%; I² = 90.32%). For 5 RCTs included comparing the efficacy between rifaximin and placebo or active controls, there was no significant difference (n = 203, risk ratio = 1.14, 95%CI: 0.59 to 2.19, P = 0.15, I² = 38%). Subgroup analysis and meta-regression indicated a dose-dependent eradication rate of rifaximin for SIBO.

CONCLUSION

Rifaximin is effective and safe in eradicating SIBO, with a dose-dependent efficacy and commonly associated with the improvement of the gastrointestinal symptoms and underlying diseases.

Identification of minimal hepatic encephalopathy based on dynamic functional connectivity

To investigate whether dynamic functional connectivity (DFC) metrics can better identify minimal hepatic encephalopathy (MHE) patients from cirrhotic patients without any hepatic encephalopathy (noHE) and healthy controls (HCs). Resting-state functional MRI data were acquired from 62 patients with cirrhosis (MHE, n = 30; noHE, n = 32) and 41 HCs. We used the sliding time window approach and functional connectivity analysis to extract the time-varying properties of brain connectivity. Three DFC characteristics (i.e., strength, stability, and variability) were calculated. For comparison, we also calculated the static functional connectivity (SFC). A linear support vector machine was used to differentiate MHE patients from noHE and HCs using DFC and SFC metrics as classification features. The leave-one-out cross-validation method was used to estimate the classification performance. The strength of DFC (DFC-Dstrength) achieved the best accuracy (MHE vs. noHE, 72.5%; MHE vs. HCs, 84%; and noHE vs. HCs, 88%) compared to the other dynamic features. Compared to static features, the classification accuracies of the DFC-Dstrength feature were improved by 10.5%, 8%, and 14% for MHE vs. noHE, MHE vs. HC, and noHE vs. HCs, respectively. Based on the DFC-Dstrength, seven nodes were identified as the most discriminant features to classify MHE from noHE, including left inferior parietal lobule, left supramarginal gyrus, left calcarine, left superior frontal gyrus, left cerebellum, right postcentral gyrus, and right insula. In summary, DFC characteristics have a higher classification accuracy in identifying MHE from cirrhosis patients. Our findings suggest the usefulness of DFC in capturing neural processes and identifying disease-related biomarkers important for MHE identification.