Gut flora and bacterial translocation in chronic liver disease

Using a human colonoid-derived monolayer to study bacteriophage translocation

Bacteriophages (phages) are estimated to be the most abundant microorganisms on Earth. Their presence in human blood suggests that they can translocate from non-sterile sites such as the gastrointestinal tract where they are concentrated. To examine phage translocation ex vivo, we adapted a primary colonoid monolayer model possessing cell diversity and architecture, and a thick layer of mucus akin to the colonic environment in vivo. We show that the colonoid monolayer is superior to the Caco-2 cell-line model, possessing intact and organized tight junctions and generating a physiologically relevant mucus layer. We showed, using two different phages, that translocation across the colonoid monolayer was largely absent in differentiated monolayers that express mucus, unlike Caco-2 cultures that expressed little to no mucus. By stimulating mucus production or removing mucus, we further demonstrated the importance of colonic mucus in preventing phage translocation. Finally, we used etiological drivers of gut permeability (alcohol, fat, and inflammatory cytokines) to measure their effects on phage translocation, demonstrating that all three stimuli have the capacity to amplify phage translocation. These findings suggest that phage translocation does occur in vivo but may be largely dependent on colonic mucus, an important insight to consider in future phage applications.

Metagenomic analysis unveils the microbial landscape of pancreatic tumors

The composition of resident microbes in the human body is linked to various diseases and their treatment outcomes. Although studies have identified pancreatic ductal adenocarcinoma (PDAC)-associated bacterial communities in the oral and gut samples, herein, we hypothesize that the prevalence of microbiota in pancreatic tumor tissues is different as compared with their matched adjacent, histologically normal appearing tissues, and these microbial molecular signatures can be highly useful for PDAC diagnosis/prognosis. In this study, we performed comparative profiling of bacterial populations in pancreatic tumors and their respective adjacent normal tissues using 16S rRNA-based metagenomics analysis. This study revealed a higher abundance of Proteobacteria and Actinomycetota in tumor tissues compared with adjacent normal tissues. Interestingly, the linear discriminant analysis (LDA) scores unambiguously revealed an enrichment of Delftia in tumor tissues, whereas Sphingomonas, Streptococcus, and Citrobacter exhibited a depletion in tumor tissues. Furthermore, we analyzed the microbial composition between different groups of patients with different tumor differentiation stages. The bacterial genera, Delftia and Staphylococcus, were very high at the G1 stages (well differentiated) compared with G2 (well to moderate/moderately differentiated) and G3/G4 (poorly differentiated) stages. However, the abundance of Actinobacter and Cloacibacterium was found to be very high in G2 and G3, respectively. Additionally, we evaluated the correlation of programmed death-ligand (PDL1) expression with the abundance of bacterial genera in tumor lesions. Our results indicated that three genera such as Streptomyces, Cutibacterium, and Delftia have a positive correlation with PD-L1 expression. Collectively, these findings demonstrate that PDAC lesions harbor relatively different microbiota compared with their normal tumor adjacent tissues, and this information may be helpful for the diagnosis and prognosis of PADC patients.

MAIT cells in bacterial infectious diseases: heroes, villains, or both?

Due to the aggravation of bacterial drug resistance and the lag in the development of new antibiotics, it is crucial to develop novel therapeutic regimens for bacterial infectious diseases. Currently, immunotherapy is a promising regimen for the treatment of infectious diseases. Mucosal-associated invariant T (MAIT) cells, a subpopulation of innate-like T cells, are abundant in humans and can mount a rapid immune response to pathogens, thus becoming a potential target of immunotherapy for infectious diseases. At the site of infection, activated MAIT cells perform complex biological functions by secreting a variety of cytokines and cytotoxic substances. Many studies have shown that MAIT cells have immunoprotective effects because they can bridge innate and adaptive immune responses, leading to bacterial clearance, tissue repair, and homeostasis maintenance. MAIT cells also participate in cytokine storm generation, tissue fibrosis, and cancer progression, indicating that they play a role in immunopathology. In this article, we review recent studies of MAIT cells, discuss their dual roles in bacterial infectious diseases and provide some promising MAIT cell-targeting strategies for the treatment of bacterial infectious diseases.

Biomarkers of gut barrier dysfunction and risk of hepatocellular carcinoma in the REVEAL-HBV and REVEAL-HCV cohort studies

Gut barrier dysfunction can result in the liver being exposed to an elevated level of gut-derived bacterial products via portal circulation. Growing evidence suggests that systemic exposure to these bacterial products promotes liver diseases including hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). However, prospective studies have not examined the association between biomarkers of gut barrier dysfunction and HCC risk in a population of hepatitis B or C viral (HBV/HCV) carriers. We investigated whether prediagnostic, circulating biomarkers of gut barrier dysfunction were associated with HCC risk, using the Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer (REVEAL)-HBV and REVEAL-HCV cohorts from Taiwan. REVEAL-HBV included 185 cases and 161 matched controls, and REVEAL-HCV 96 cases and 96 matched controls. The biomarkers quantitated were immunoglobulin A (IgA), IgG, and IgM against lipopolysaccharide (LPS) and flagellin, soluble CD14 (an LPS coreceptor), and LPS-binding protein (LBP). Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between biomarker levels and HCC were calculated using multivariable-adjusted logistic regression. A doubling of the circulating levels of antiflagellin IgA or LBP was associated with a 76% to 93% increased risk of HBV-related HCC (OR per one unit change in log2 antiflagellin IgA = 1.76, 95% CI: 1.06-2.93; OR for LBP = 1.93, 95% CI: 1.10-3.38). None of the other markers were associated with an increased risk of HBV-related or HCV-related HCC. Results were similar when cases diagnosed in the first 5 years of follow-up were excluded. Our findings contribute to understanding the interplay of gut barrier dysfunction and primary liver cancer etiology.

Tumor microenvironment-mediated immune evasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is the third leading cause of tumor-related mortality worldwide. In recent years, the emergency of immune checkpoint inhibitor (ICI) has revolutionized the management of HCC. Especially, the combination of atezolizumab (anti-PD1) and bevacizumab (anti-VEGF) has been approved by the FDA as the first-line treatment for advanced HCC. Despite great breakthrough in systemic therapy, HCC continues to portend a poor prognosis owing to drug resistance and frequent recurrence. The tumor microenvironment (TME) of HCC is a complex and structured mixture characterized by abnormal angiogenesis, chronic inflammation, and dysregulated extracellular matrix (ECM) remodeling, collectively contributing to the immunosuppressive milieu that in turn prompts HCC proliferation, invasion, and metastasis. The tumor microenvironment coexists and interacts with various immune cells to maintain the development of HCC. It is widely accepted that a dysfunctional tumor-immune ecosystem can lead to the failure of immune surveillance. The immunosuppressive TME is an external cause for immune evasion in HCC consisting of 1) immunosuppressive cells; 2) co-inhibitory signals; 3) soluble cytokines and signaling cascades; 4) metabolically hostile tumor microenvironment; 5) the gut microbiota that affects the immune microenvironment. Importantly, the effectiveness of immunotherapy largely depends on the tumor immune microenvironment (TIME). Also, the gut microbiota and metabolism profoundly affect the immune microenvironment. Understanding how TME affects HCC development and progression will contribute to better preventing HCC-specific immune evasion and overcoming resistance to already developed therapies. In this review, we mainly introduce immune evasion of HCC underlying the role of immune microenvironment, describe the dynamic interaction of immune microenvironment with dysfunctional metabolism and the gut microbiome, and propose therapeutic strategies to manipulate the TME in favor of more effective immunotherapy.

Is it possible to intervene early cirrhosis by targeting toll-like receptors to rebalance the intestinal microbiome?

Cirrhosis is a progressive chronic liver disease caused by one or more causes and characterized by diffuse fibrosis, pseudolobules, and regenerated nodules. Once progression to hepatic decompensation, the function of the liver and other organs is impaired and almost impossible to reverse and recover, which often results in hospitalization, impaired quality of life, and high mortality. However, in the early stage of cirrhosis, there seems to be a possibility of cirrhosis reversal. The development of cirrhosis is related to the intestinal microbiota and activation of toll-like receptors (TLRs) pathways, which could regulate cell proliferation, apoptosis, expression of the hepatomitogen epiregulin, and liver inflammation. Targeting regulation of intestinal microbiota and TLRs pathways could affect the occurrence and development of cirrhosis and its complications. In this paper, we first reviewed the dynamic change of intestinal microbiota and TLRs during cirrhosis progression. And further discussed the interaction between them and potential therapeutic targets to reverse early staged cirrhosis.

Gut microbiota-modulating agents in alcoholic liver disease: Links between host metabolism and gut microbiota

Alcoholic liver disease (ALD) involves a wide spectrum of diseases, including asymptomatic hepatic steatosis, alcoholic hepatitis, hepatic fibrosis, and cirrhosis, which leads to morbidity and mortality and is responsible for 0.9% of global deaths. Alcohol consumption induces bacterial translocation and alteration of the gut microbiota composition. These changes in gut microbiota aggravate hepatic inflammation and fibrosis. Alteration of the gut microbiota leads to a weakened gut barrier and changes host immunity and metabolic function, especially related to bile acid metabolism. Modulation and treatment for the gut microbiota in ALD has been studied using probiotics, prebiotics, synbiotics, and fecal microbial transplantation with meaningful results. In this review, we focused on the interaction between alcohol and gut dysbiosis in ALD. Additionally, treatment approaches for gut dysbiosis, such as abstinence, diet, pro-, pre-, and synbiotics, antibiotics, and fecal microbial transplantation, are covered here under ALD. However, further research through human clinical trials is warranted to evaluate the appropriate gut microbiota-modulating agents for each condition related to ALD.

Granulocyte-Macrophage Colony-Stimulating Factor Modulates Myeloid-Derived Suppressor Cells and Treg Activity in Decompensated Cirrhotic Patients With Sepsis

Background

Decompensated cirrhosis patients are more prone to bacterial infections. Myeloid-derived suppressor cells (MDSCs) expand in sepsis patients and disrupt immune cell functions. Granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy helps in restoring immune cell functions and resolving infections. Its role in MDSC modulation in cirrhosis with sepsis is not well understood.

Methods

A total of 164 decompensated cirrhotic—62 without (w/o), 72 with sepsis, and 30 with sepsis treated with GM-CSF—and 15 healthy were studied. High-dimensional flow cytometry was performed to analyze MDSCs, monocytes, neutrophils, CD4 T cells, and Tregs at admission and on days 3 and day 7. Ex vivo co-cultured MDSCs with T cells were assessed for proliferation and apoptosis of T cells and differentiation to Tregs. Plasma factors and mRNA levels were analyzed by cytokine-bead assay and qRT-PCR.

Results

Frequencies of MDSCs and Tregs were significantly increased (p = 0.011 and p = 0.02) with decreased CD4 T cells (p = 0.01) in sepsis than w/o sepsis and healthy controls (HCs) (p = 0.000, p = 0.07, and p = 0.01) at day 0 and day 7. In sepsis patients, MDSCs had increased IL-10, Arg1, and iNOS mRNA levels (p = 0.016, p = 0.043, and p = 0.045). Ex vivo co-cultured MDSCs with T cells drove T-cell apoptosis (p = 0.03, p = 0.03) with decreased T-cell proliferation and enhanced FOXP3⁺ expression (p = 0.044 and p = 0.043) in sepsis compared to w/o sepsis at day 0. Moreover, blocking the MDSCs with inhibitors suppressed FOXP3 expression. GM-CSF treatment in sepsis patients significantly decreased MDSCs and FOXP3⁺ Tregs but increased CD4 T-cell functionality and improved survival.

Conclusion

MDSCs have an immunosuppressive function by expanding FOXP3⁺ Tregs and inhibiting CD4⁺ T-cell proliferation in sepsis. GM-CSF treatment suppressed MDSCs, improved T-cell functionality, and reduced Tregs in circulation.

Plasma Proteomic Analysis Identified Proteins Associated with Faulty Neutrophils Functionality in Decompensated Cirrhosis Patients with Sepsis

Decompensated cirrhosis (DC) is susceptible to infections and sepsis. Neutrophils and monocytes provide the first line of defense to encounter infection. We aimed to evaluate proteins related to neutrophils functionality in sepsis. 70 (DC), 40 with sepsis, 30 without (w/o) sepsis and 15 healthy controls (HC) plasma was analyzed for proteomic analysis, cytokine bead array, endotoxin, cell free DNA and whole blood cells were analyzed for nCD64-mHLADR index, neutrophils-monocytes, functionality and QRT-PCR. nCD64-mHLADR index was significantly increased (p < 0.0001) with decreased HLA-DR expression on total monocytes in sepsis (p = 0.045). Phagocytic activity of both neutrophils and monocytes were significantly decreased in sepsis (p = 0.002 and p = 0.0003). Sepsis plasma stimulated healthy neutrophils, showed significant increase in NETs (neutrophil extracellular traps) and cell free DNA (p = 0.049 and p = 0.04) compared to w/o sepsis and HC. Proteomic analysis revealed upregulated- DNAJC13, TMSB4X, GPI, GSTP1, PNP, ANPEP, COTL1, GCA, APOA1 and PGAM1 while downregulated- AHSG, DEFA1,SERPINA3, MPO, MMRN1and PROS1 proteins (FC > 1.5; p < 0.05) associated to neutrophil activation and autophagy in sepsis. Proteins such as DNAJC13, GPI, GSTP1, PNP, ANPEP, COTL1, PGAM1, PROS1, MPO, SERPINA3 and MMRN1 showed positive correlation with neutrophils activity and number, oxidative burst activity and clinical parameters such as MELD, MELD Na and Bilirubin. Proteomic analysis revealed that faulty functionality of neutrophils may be due to the autophagy proteins i.e., DNAJC13, AHSG, TMSB4X, PROS1 and SERPINA3, which can be used as therapeutic targets in decompensated cirrhosis patients with sepsis.

The microbial composition of the initial insult can predict the prognosis of experimental sepsis

We hypothesized that the composition of sepsis-inducing bacterial flora influences the course of fecal peritonitis in rodents. Saline or fecal suspensions with a standardized dose range of bacterial colony-forming units (CFUs) were injected intraperitoneally into Sprague–Dawley rats. The qualitative composition of the initial inoculum and the ascites was analyzed separately by MALDI-TOF mass spectrometry. Invasive monitoring was conducted in separate anesthetized groups (n = 12–13/group) after 12, 24, 48 and 72 h to determine rat-specific organ failure assessment (ROFA) scores. Death and ROFA scores peaked at 24 h. At this time, 20% mortality occurred in animals receiving a monomicrobial E. coli suspension, and ROFA scores were significantly higher in the monomicrobial subgroup than in the polymicrobial one (median 6.5; 5.0–7.0 and 5.0; 4.75–5.0, respectively). ROFA scores dropped after 48 h, accompanied by a steady decrease in ascites CFUs and a shift towards intra-abdominal monomicrobial E. coli cultures. Furthermore, we found a relationship between ascites CFUs and the evolving change in ROFA scores throughout the study. Hence, quantitatively identical bacterial loads with mono- or polymicrobial dominance lead to a different degree of sepsis severity and divergent outcomes. Initial and intraperitoneal microbiological testing should be used to improve translational research success.

Toll-Like Receptors Recognize Intestinal Microbes in Liver Cirrhosis

Liver cirrhosis is one major cause of mortality in the clinic, and treatment of this disease is an arduous task. The scenario will be even getting worse with increasing alcohol consumption and obesity in the current lifestyle. To date, we have no medicines to cure cirrhosis. Although many etiologies are associated with cirrhosis, abnormal intestinal microbe flora (termed dysbiosis) is a common feature in cirrhosis regardless of the causes. Toll-like receptors (TLRs), one evolutional conserved family of pattern recognition receptors in the innate immune systems, play a central role in maintaining the homeostasis of intestinal microbiota and inducing immune responses by recognizing both commensal and pathogenic microbes. Remarkably, recent studies found that correction of intestinal flora imbalance could change the progress of liver cirrhosis. Therefore, correction of intestinal dysbiosis and targeting TLRs can provide novel and promising strategies in the treatment of liver cirrhosis. Here we summarize the recent advances in the related topics. Investigating the relationship among innate immunity TLRs, intestinal flora disorders, and liver cirrhosis and exploring the underlying regulatory mechanisms will assuredly have a bright future for both basic and clinical research.

Exposure to nitenpyram during pregnancy causes colonic mucosal damage and non-alcoholic steatohepatitis in mouse offspring: The role of gut microbiota

Environmental pollutants contribute to metabolic diseases. Recent studies have shown that exposure to environmental chemicals during pregnancy can cause obesity and other metabolic diseases in mouse offspring, and these effects have been linked to the changes in the gut microbiota. However, the mechanism of such effects has yet to be fully elucidated. In the present study, we aimed at assessing the metabolic effects of exposure to an environmental pollutant, like nitenpyram, during pregnancy on mouse offspring, and we further explored its potential mechanisms. Our results have demonstrated that exposure to nitenpyram (4 mg/kg/day body weight) in mice during pregnancy (from gestational day 6 to gestational day 19) can increase the count of Desulfovibrio strains (increased from 0.55% to 5.56%) and the concentration of H₂S (increased from 28.98 to 41.31 nmol/g) in the gut of the offspring. These alterations can destroy colonic mucosa and increase intestinal inflammation and bacterial translocation, thus leading to non-alcoholic steatohepatitis (NASH). Overall, these results highlight the role of the gut microbiota in developing intestinal barrier dysfunction and liver inflammation and provide new insights into the pathophysiology of NASH.

Comparison of Vasopressor Duration in Septic Shock Patients With and Without Cirrhosis

BACKGROUND

Patients with cirrhosis have immune dysfunction, altered inflammatory response, and hemodynamic changes which increase risk of septic shock and potentially prolong management with fluids, vasopressors, and other therapies. Due to limited available guidance, this study aimed to characterize vasopressor use in patients with cirrhosis in relation to patients without cirrhosis in septic shock.

METHODS

This was a retrospective matched cohort analysis of 122 patients admitted to the intensive care unit (ICU) at an academic medical center from January 2015 to November 2017. Patients were grouped based on the presence or absence of cirrhosis and matched based on severity of illness scoring. The primary outcome was vasopressor duration. Secondary comparisons included total vasopressor requirement, length of hospital and ICU stay, in-hospital mortality, change in organ function, and discharge disposition.

RESULTS

The group with cirrhosis had significantly longer median (interquartile range [IQR]) durations of vasopressor therapy compared with the group without cirrhosis (86.0 [42.0-164.5] vs 39.0 [14.5-82.0] hours; P = 0.003) leading to increased median (IQR) vasopressor exposure (71.7 [15.5-239.5] vs 24.7 [5.3-77.9] mg norepinephrine [NE] equivalents; P = 0.003). No difference was found in in-hospital mortality between groups. However, regression analysis showed vasopressor exposure was associated with in-hospital mortality.

CONCLUSION AND RELEVANCE

Patients with cirrhosis in septic shock have increased vasopressor durations and overall requirements compared with patients without cirrhosis. Increased durations and requirements is associated with poorer outcomes independent of presence of cirrhosis. Future studies are needed to improve vasopressor treatment strategies and end points utilized in cirrhosis.

Over-expression of MiR-122 promotes apoptosis of hepatocellular carcinoma via targeting TLR4

INTRODUCTION AND OBJECTIVE

MiR-122 has been regarded as a tumor suppressor. Toll-like receptor 4 (TLR4) has been found to be closely related to metastasis and immune escape of hepatocellular carcinoma (HCC). In the study, we sought to investigate the effect of miR-122 on HCC and the expression of TLR4.

PATIENTS OR MATERIALS AND METHODS

Real-time PCR and Western blot were performed to detect the expressions of target factors. CCK-8 and flow cytometry analysis were employed to evaluate cell viability and apoptosis, respectively. Luciferase reporter assay was used to determine whether miR-122 could directly regulate the expression of TLR4. Enzyme-linked Immuno Sorbent Assay was adopted to detect the secretion of inflammatory cytokines.

RESULTS

Both down-regulation of miR-122 and up-regulation of TLR4 were found to be correlated with low overall survival rate of HCC patients. TLR4 may be a direct target gene of miR-122. Over-expression of miR-122 induced apoptosis and inhibited cell viability of HCC by down-regulating TLR4, enhanced the expression of pro-apoptotic genes and suppressed the expression of anti-apoptotic genes. MiR-122 inhibited expressions and activities of inflammatory cytokines, including vascular endothelial growth factor (VEGF), interleukin 6 (IL-6), cyclooxygenase-2 (Cox-2) and prostaglandin E2 (PGE2) and also reduced the expression of matrix metallopeptidase 9 (MMP-9). Furthermore, activities of phosphatidylinositide 3-kinases (PI3K), Akt and nuclear factor-kappa B (NF-κB) were suppressed by miR-122.

CONCLUSIONS

Down-regulation of miR-122 facilitated the immune escape of HCC by targeting TLR4, which was related to PI3K/Akt/NF-κB signaling pathways. Our study may provide a possible strategy for the treatment of HCC.

NOD2 in hepatocytes engages a liver-gut axis to protect against steatosis, fibrosis, and gut dysbiosis during fatty liver disease in mice

Obesity promotes nonalcoholic fatty liver disease (NAFLD). The intestinal microbiota contributes to NAFLD progression through a gut-to-liver pathway that promotes inflammation and fibrosis. Gut microbiota-derived factors can travel to the liver and activate immune responses in liver resident cells to promote inflammation and NAFLD. Little is known about bacterial sensors or immune responses that can protect against NAFLD. We tested whether the bacterial cell wall sensor nucleotide-binding oligomerization domain-containing (NOD)2 protects against diet-induced NAFLD in mice. Whole body deletion of NOD2 exacerbated liver steatosis and fibrosis in mice fed a NAFLD-promoting diet. Mice with a hepatocyte-specific deletion of NOD2 (Nod2^-/-HKO) also had higher liver steatosis and fibrosis compared with littermate wild-type mice (WT) fed a NAFLD-promoting diet. Hepatocyte-specific NOD2 deletion altered the composition of the gut microbiome. Nod2^-/-HKO mice had increased relative abundance of Clostridiales and lower Erysipelotrichaceae among other changes in cecal bacteria compared with littermate WT mice. Hepatocyte-specific NOD2 deletion altered a transcriptional program of liver inflammation, metabolism, and fibrosis. Nod2^-/-HKO mice had higher levels of transcripts involved in lipid and cholesterol metabolism. Nod2^-/-HKO mice had higher transcript levels of transforming growth factor-β and collagen isoforms, which coincided with higher levels of liver collagen compared with WT mice. These data show that bacterial cell wall sensing within hepatocytes can engage retrograde cross-talk from the liver to the gut, where liver immunity communicates with the gut to influence the intestinal host-microbe relationship during diet-induced NAFLD, and NOD2 within the hepatocyte confers protection from liver steatosis and fibrosis.

Prediagnostic concentrations of circulating bile acids and hepatocellular carcinoma risk: REVEAL-HBV and HCV studies

Hepatocellular carcinoma (HCC) is the dominant histologic type of liver cancer, accounting for 75% of cases. Growing evidence suggests that the cross-talk between the gut microbiome and metabolome (ie, gut-liver axis) are related to the development of hepatic inflammation, and ultimately, HCC. Bile acids are metabolites, derived from cholesterol and synthesized in the liver, which may have a critical role in regulation of the gut-liver axis. We investigated whether prediagnostic circulating bile acids were associated with HCC risk, using the Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer (REVEAL)-Hepatitis B Virus (HBV) and REVEAL-Hepatitis C Virus (HCV) cohorts from Taiwan. Fifteen bile acids were quantitated using liquid chromatography, from 185 cases and 161 matched controls in REVEAL-HBV and 96 cases and 96 matched controls in REVEAL-HCV. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between bile acid levels and HCC were calculated using multivariable-adjusted logistic regression. Higher levels of glycine and taurine conjugated primary bile acids were associated with a 2- to 8-fold increased risk of HBV- (eg, glycocholic acid OR_Q4vsQ1 = 3.38, 95% CI: 1.48-7.71, P_trend < .003) and HCV-related HCC (eg, OR = 8.16, 95% CI: 2.21-30.18, P_trend < .001). However, higher levels of the secondary bile acid deoxycholic acid were inversely associated with HBV-related HCC risk (OR = 0.41, 95% CI: 0.19-0.88, P_trend = .02). Our study provides evidence that higher concentrations of bile acids-specifically, conjugated primary bile acids-are associated with increased HCC risk. However, our study does not support the hypothesis that higher levels of secondary bile acids increase liver cancer risk; indeed, deoxycholic acid may be associated with a decreased HCC risk.

Effect of Neotype Rectal Mild Hypothermia Therapy on Intestinal Bacterial Translocation in Rats with Hypoxic-Ischemic Brain Damage

BACKGROUND Previous studies have shown that a neotype rectal cooling device can induce mild hypothermia (MH) in Sprague-Dawley rats with ischemic-hypoxic brain damage (HIBD) and inhibit cell apoptosis in the hippocampal CAl region, and does not cause damage to rectal tissues. The present study aimed to investigate the effect of rectal MH on bacterial translocation (BT) in Sprague-Dawley rats with HIBD. MATERIAL AND METHODS A total of 60 Sprague-Dawley rats were randomly divided into 4 groups: a control group (group C), a normothermia group (group NT), a cooling blanket group (group CB), and a rectal cooling group (group RC). Rats in group CB and group RC received MH using a cooling blanket and rectal cooling device after HIBD model establishment. Then, we measured diamine oxidase (DAO) and D-lactate level separately in groups NT, CB, and RC. Finally, the spleen, liver, and mesenteric lymph nodes were collected for bacterial culture, and rectal tissues were collected for H&E staining. RESULTS The therapeutic outcome was better in Sprague-Dawley rats receiving rectal MH without rectal injury compared to rats in group CB. Escherichia coli (E. coli) was found in MLNs in group RC. E. coli, Proteus vulgaris, Stenotrophomonas maltophilia, and Acinetobacter lwoffii were detected in the rats of groups CB and NT. At 12 h following rectal MH, DAO and D-lactate levels were lower than in group NT. CONCLUSIONS The neotype rectal MH cooling method could be a potential strategy to induce rapid, controllable hypothermia, thus reducing the possibility of inflammatory cell infiltration and BT incidence.

Prognostic impact of toll-like receptors 2 and 4 expression on monocytes in Egyptian patients with hepatocellular carcinoma

Toll-like receptors (TLRs) have a role in chronic inflammation. Still, little is known about the expression of TLRs in hepatocellular carcinoma (HCC). Herein, we tried to assess the prognostic value of TLR2 and TLR4 expression on circulating monocytes in HCC patients and correlate their levels with some clinical, laboratory data, and treatment outcomes. Forty patients with hepatic focal lesions diagnosed radiologically as HCC by triphasic multislice CT pelviabdominal and chest, and in some patients MRI diffusion and 38 age and sex matching healthy controls were enrolled in the study. Subjects were evaluated for liver functions, alpha-fetoprotein (AFP), imaging, response to different treatments, and overall survival. TLR2 and TLR4 expression by monocytes was detected by flow cytometry. The expression of both TLR2 and TLR4 on monocytes was significantly increased in HCC patients than the controls, in patients with more progressive HCC than those with lower progression and in patients with poor response to treatment than patients with better treatment response. Moreover, their levels showed positive correlations with ALT, AST, and AFP and inverse correlations with the overall survival of HCC patients. The results of the current study suggest that increased expression ofTLR2 and TLR4 on peripheral monocytes might reflect the development and progression of HCC and can be used to indicate poor prognosis. In addition, high expression of TLR2 correlated significantly with poor response to treatment, while high expression of both TLR2 and TLR4 were associated with poor survival. Our findings will help to design more studies on the role of TLRs in HCC pathogenesis and prognosis which may provide new therapeutic targets for HCC.

Clinical predictors and impact of bacteremia in cirrhotic patients with acute skin and skin structure infection

OBJECTIVE

Acute bacterial skin and skin structure infection (ABSSSI) is a common cause of acute admissions in patients with cirrhosis worldwide, but the disease is not well-understood epidemiologically with respect to factors that determine positive blood cultures or patient mortality. The aim of this study was to understand the utility of blood cultures and the association between bacteremia and mortality in cirrhotic patients with ABSSSI. We conducted a retrospective study to investigate factors associated with positive blood cultures and mortality in cirrhotic patients with ABSSSI.

METHODS

A retrospective cohort study of hospitalized adult cirrhotic patients with ABSSSI was conducted in a tertiary hospital in Taiwan between March 2015 and December 2016.

RESULTS

A total of 122 hospitalized cirrhotic patients with ABSSSI were included. The overall mortality rate was 9% (11/122), and 23 patients had positive blood culture results. Comorbidities that were significant risk factors for a positive blood culture included diabetes mellitus, acute kidney injury (AKI), and acute-on-chronic liver failure (ACLF). Significant risk factors evident in laboratory evaluations included higher model for end-stage liver disease (MELD) score, higher serum lactate, and lower serum albumin level. Bacteremia was also a significant factor associated with mortality.

CONCLUSION

A blood culture should be considered for cirrhotic patients with ABSSSI with diabetes mellitus, AKI, ACLF or those exhibiting abnormal albumin, lactate levels, or high MELD score because of the positive correlation between bacteremia and mortality.

Pregnane X receptor activation by its natural ligand Ginkgolide-A improves tight junction proteins expression and attenuates bacterial translocation in cirrhosis

BACKGROUND AND AIMS

Pregnane X receptor (PXR) is a ligand-activated transcription factor and nuclear receptor expressed ubiquitously along gut-liver-axis. Inflammatory bowel disorders have been reported to implicate PXR in maintaining tight junction (TJ) integrity and countering inflammation. However, the hepatoprotective role of PXR activation in soothing bacterial translocation in liver cirrhosis has not been explored. Ginkgolide A (GA), a terpene trilactone from Ginkgo Biloba extract, is a natural ligand of rodent and human PXR. This study aims to investigate the effect of GA in activating PXR and improving associated tight junction integrity and reducing bacterial translocation in gut-liver axis of CCl₄ induced cirrhosis model.

METHODS

Swiss albino mice were administered with CCl₄ (0.5 ml/kg body weight, i.p) in corn oil for 12 weeks at an interval of two times a week. Following ascites induction, mice were randomized & administered 100 mg/kg body weight of GA through oral gavage for 2 weeks. At termination, blood, gut and liver tissues were collected for biochemical and molecular studies.

RESULTS

When compared to naïve mice, protein expression of hepatic and small intestinal PXR, CYP3A, ZO-1 and occludin were found to be significantly (p < 0.01) decreased in CCl₄ induced cirrhotic mice. Treatment with GA to cirrhotic mice significantly (p < 0.05) induced the expression of both hepatic and small intestinal PXR, CYP3A, ZO-1 and Occludin. Furthermore, increased (p < 0.01) hepatic and small intestinal NFκB was observed in CCl₄ induced cirrhotic mice that was significantly (p < 0.05) lowered following GA treatment. Over expression of TLR4/MyD88/NFκB axis and its downstream pro-inflammatory mediators TNF-α, IL6 and IFN-γ were observed in CCl₄ induced mice, and these indices were abrogated significantly after GA treatment. Furthermore, significantly increased plasma levels of bacterial translocation markers LBP and procalcitonin were found in CCl₄ mice, which were reduced significantly (p < 0.05 & p < 0.0001) after GA treatment.

CONCLUSION

In conclusion, our data supports the hypothesis that, GA treatment to CCl₄ induced cirrhotic mice, activated hepatic and small intestinal PXR and diminished inflammation, thereby improving tight junction integrity and attenuating bacterial translocation.

Bacterial Translocation and Risk of Liver Cancer in a Finnish Cohort

BACKGROUND

Elevated systemic exposure to gut-derived bacterial products has been associated with hepatic inflammation and chronic liver diseases, potentially increasing the risk of liver cancer. However, only one prior study prospectively examined exposure to bacterial products in the circulation and risk of liver cancer, with a relatively limited coverage of biomarkers.

METHODS

We conducted a nested case-control study (224 liver cancer cases and 224 matched controls) in a large cohort of Finnish male smokers followed from baseline (1985-1988) to 2014. The associations between a panel of biomarkers for bacterial translocation and the risk of liver cancer were assessed using multivariable-adjusted conditional logistic regression. The biomarkers included immunoglobulin (Ig) A, IgG, and IgM against lipopolysaccharide (LPS) and flagellin, soluble CD14 (an LPS coreceptor), and the LPS-binding protein.

RESULTS

Anti-flagellin IgA [odds ratios (OR), 2.79; 95% confidence intervals (CI), 1.34-5.78; P trend = 0.01] and anti-LPS IgA (2.44; 95% CI, 1.33-4.48; P trend < 0.01) were significantly associated with risk of liver cancer. When restricting the analysis to histologically classified hepatocellular carcinoma, the ORs were 4.18 (95% CI, 1.60-10.92; P trend < 0.01) and 2.48 (95% CI, 1.16-5.29; P trend < 0.01), respectively. The results were not substantially changed after excluding cases diagnosed within the first 5 years of follow-up and those with hepatitis C virus infection.

CONCLUSIONS

Antibodies to flagellin and LPS were associated with increased risk of liver cancer.

IMPACT

Gut-derived bacterial translocation into the circulation may play a role in the development of primary liver cancer. Our findings could contribute to the understanding of primary liver cancer etiology and further prevention efforts.

Deoxyribonuclease I Activity, Cell-Free DNA, and Risk of Liver Cancer in a Prospective Cohort

Background

Circulating cell-free DNA (cfDNA) is a proposed latent biomarker for several cancers, including liver cancer. Deoxyribonucleases (DNases) facilitate the timely and efficient degradation of cfDNA, leading us to hypothesize that DNase I and/or II might be a more sensitive early biomarker than cfDNA. To test this hypothesis, a study was conducted in a large, prospective cohort.

Methods

A nested case-control study (224 liver cancer case patients and 224 matched control subjects) was conducted in a cohort of Finnish male smokers, followed from baseline (1985-1988) to 2014. The associations among DNase I activity, cfDNA, and the risk of liver cancer were assessed using multivariable-adjusted conditional logistic regression.

Results

DNase I activity, whether measured as radius (mm) or as units per milliliter, was statistically significantly associated with increased risk of liver cancer (P _trend <.01). DNase I activity in the highest quartile was associated with a greater than threefold risk of developing liver cancer (DNase I activity radius >2.7 mm, hazard ratio [HR] = 3.03, 95% confidence interval [CI] = 1.59 to 5.77; DNase I activity >2.72 units/mL, HR = 3.30, 95% CI = 1.64 to 6.65). The strength of this association was not substantially altered by exclusion of cases diagnosed within the first five years of follow-up or those with hepatitis C virus (HCV) infection. In contrast, cfDNA and DNase II was not statistically significantly associated with risk of liver cancer.

Conclusions

DNase I activity was a superior latent biomarker of liver cancer than cfDNA. These findings advance the goal of developing a means to detect liver cancer years well before the development of clinical manifestations.

Targeting gut microbiota in hepatocellular carcinoma: probiotics as a novel therapy

Hepatocellular carcinoma (HCC), the most common primary liver cancer, is one of the dreaded complications of chronic liver disease. Recent experimental and clinical studies have revealed that the alteration of gut-liver axis plays a pivotal role in the onset of chronic liver diseases, including HCC. Altered gut microbiota and endotoxemia are increasingly recognized as critical components in promoting the progression of chronic liver diseases to HCC. Probiotics have been suggested as a novel, safe and cost-effective approach to prevent or treat HCC. Mechanisms by which probiotics exerts their anti-cancer effects include their ability to bind carcinogens, modulation of gut microbiota, improvement of intestinal barrier function, and immunomodulation. This review summarizes the literature findings of the changes in gut microbiota linked to HCC, and discusses the possible therapeutic implications of probiotics for HCC.

NADPH oxidase 4 modulates hepatic responses to lipopolysaccharide mediated by Toll-like receptor-4

Chronic inflammation plays a key role in development of many liver diseases. Stimulation of Toll-like receptor 4 (TLR4) by bacterial lipopolysaccharide (LPS) initiates inflammation and promotes development of hepatocellular carcinoma and other liver diseases. NADPH oxidases contribute to LPS-induced reactive oxygen species (ROS) production and modulate TLR responses, but whether these enzymes function in TLR4 responses of hepatocytes is unknown. In the present work, we examined the role of NADPH oxidase 4 (Nox4) in LPS-induced TLR4 responses in human hepatoma cells and wildtype and Nox4-deficient mice. We found that LPS increased expression of Nox4, TNF-α, and proliferating cell nuclear antigen (PCNA). Nox4 silencing suppressed LPS-induced TNF-α and PCNA increases in human cells. The LPS-induced TNF-α increases were MyD88-dependent, and were attenuated in primary hepatocytes isolated from Nox4-deficient mice. We found that Nox4 mediated LPS-TLR4 signaling in hepatocytes via NF-ĸB and AP-1 pathways. Moreover, the effect of Nox4 depletion was time-dependent; following six weeks of repeated LPS stimulation in vivo, hepatic TNF-α and PCNA responses subsided in Nox4-deficient mice compared with wildtype mice. Therefore, our data suggest that Nox4 mediates LPS-TLR4 signaling in human hepatoma cells and murine hepatocytes and may contribute to the ability of LPS to stimulate liver pathology.

Probiotics for people with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure or portosystemic shunt or both. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient's quality of life and daily functioning, and represent a significant burden on healthcare resources. Probiotics are live micro-organisms, which when administered in adequate amounts, may confer a health benefit on the host.

OBJECTIVES

To determine the beneficial and harmful effects of probiotics in any dosage, compared with placebo or no intervention, or with any other treatment for people with any grade of acute or chronic hepatic encephalopathy. This review did not consider the primary prophylaxis of hepatic encephalopathy.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, conference proceedings, reference lists of included trials, and the World Health Organization International Clinical Trials Registry Platform until June 2016.

SELECTION CRITERIA

We included randomised clinical trials that compared probiotics in any dosage with placebo or no intervention, or with any other treatment in people with hepatic encephalopathy.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We conducted random-effects model meta-analysis due to obvious heterogeneity of participants and interventions. We defined a P value of 0.05 or less as significant. We expressed dichotomous outcomes as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 21 trials with 1420 participants, of these, 14 were new trials. Fourteen trials compared a probiotic with placebo or no treatment, and seven trials compared a probiotic with lactulose. The trials used a variety of probiotics; the most commonly used group of probiotic was VSL#3, a proprietary name for a group of eight probiotics. Duration of administration ranged from 10 days to 180 days. Eight trials declared their funding source, of which six were independently funded and two were industry funded. The remaining 13 trials did not disclose their funding source. We classified 19 of the 21 trials at high risk of bias.We found no effect on all-cause mortality when probiotics were compared with placebo or no treatment (7 trials; 404 participants; RR 0.58, 95% CI 0.23 to 1.44; low-quality evidence). No-recovery (as measured by incomplete resolution of symptoms) was lower for participants treated with probiotic (10 trials; 574 participants; RR 0.67, 95% CI 0.56 to 0.79; moderate-quality evidence). Adverse events were lower for participants treated with probiotic than with no intervention when considering the development of overt hepatic encephalopathy (10 trials; 585 participants; RR 0.29, 95% CI 0.16 to 0.51; low-quality evidence), but effects on hospitalisation and change of/or withdrawal from treatment were uncertain (hospitalisation: 3 trials, 163 participants; RR 0.67, 95% CI 0.11 to 4.00; very low-quality evidence; change of/or withdrawal from treatment: 9 trials, 551 participants; RR 0.70, 95% CI 0.46 to 1.07; very low-quality evidence). Probiotics may slightly improve quality of life compared with no intervention (3 trials; 115 participants; results not meta-analysed; low-quality evidence). Plasma ammonia concentration was lower for participants treated with probiotic (10 trials; 705 participants; MD -8.29 μmol/L, 95% CI -13.17 to -3.41; low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.When probiotics were compared with lactulose, the effects on all-cause mortality were uncertain (2 trials; 200 participants; RR 5.00, 95% CI 0.25 to 102.00; very low-quality evidence); lack of recovery (7 trials; 430 participants; RR 1.01, 95% CI 0.85 to 1.21; very low-quality evidence); adverse events considering the development of overt hepatic encephalopathy (6 trials; 420 participants; RR 1.17, 95% CI 0.63 to 2.17; very low-quality evidence); hospitalisation (1 trial; 80 participants; RR 0.33, 95% CI 0.04 to 3.07; very low-quality evidence); intolerance leading to discontinuation (3 trials; 220 participants; RR 0.35, 95% CI 0.08 to 1.43; very low-quality evidence); change of/or withdrawal from treatment (7 trials; 490 participants; RR 1.27, 95% CI 0.88 to 1.82; very low-quality evidence); quality of life (results not meta-analysed; 1 trial; 69 participants); and plasma ammonia concentration overall (6 trials; 325 participants; MD -2.93 μmol/L, 95% CI -9.36 to 3.50; very low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.

AUTHORS' CONCLUSIONS

The majority of included trials suffered from a high risk of systematic error ('bias') and a high risk of random error ('play of chance'). Accordingly, we consider the evidence to be of low quality. Compared with placebo or no intervention, probiotics probably improve recovery and may lead to improvements in the development of overt hepatic encephalopathy, quality of life, and plasma ammonia concentrations, but probiotics may lead to little or no difference in mortality. Whether probiotics are better than lactulose for hepatic encephalopathy is uncertain because the quality of the available evidence is very low. High-quality randomised clinical trials with standardised outcome collection and data reporting are needed to further clarify the true efficacy of probiotics.

Application of CD8+ Cells Count as a Guide of Immunosuppressive Regimen Introduction for Very Sick Patients Undergoing Liver Transplantation

BACKGROUND

Immunosuppression (IS) protocols should be individualized according to the individual recipient's immunity to minimize adverse effects. The aim of this study was to determine whether preoperative levels of CD8+ T lymphocytes could be used as a guide for the introduction of IS.

METHODS

Sixteen adult liver transplantations in our institute were retrospectively analyzed. The immunosuppressive agents were temporarily withheld for 8 patients with a lower (<10%) preoperative percentage of CD8+ cells after transplant (classified as group A). In this group, postoperative immunosuppressive agents had never been used until acute rejection was suspected. Another 8 patients receiving classic IS were classified as group B. We collected their demographic features and analyzed the clinical courses.

RESULTS

The postoperative IS-free period of group A was 5 to 120 days (median, 31 days). Our data showed an inverse correlation between CD8+ levels and the severity of liver disease. Although the IS-free protocol did not present a lower incidence of infection-related events, most of them were effectively treated with antibiotics. The 1-, 3-, and 5-year overall patient survival rates were not different between those with a short-term IS-free period and those with regular IS (87.5% vs 100%, 75% vs 100%, and 62.5% vs 87.5%; P = .468). No patient died of graft failure due to acute rejection.

CONCLUSIONS

Postoperative immunosuppressive agents can be safely withheld for a period of time to preserve proper immune responses against infections in very sick recipients guided by using the CD8+ levels.

Non-selective β-blockers in advanced cirrhosis: a critical review of the effects on overall survival and renal function

Introduction

Non-selective β-blockers (NSBBs) are widely prescribed in patients with cirrhosis for primary and secondary prophylaxis of bleeding oesophageal varices. Furthermore, it has been suggested that the clinical benefits of NSBBs may extend beyond their haemodynamic effects. Recently, a potentially harmful effect has been described in patients with refractory ascites or spontaneous bacterial peritonitis.

Methodology

A comprehensive literature search on β-blockers and cirrhosis survival using the electronic databases PubMed/MEDLINE, AMED, CINAHL and the Cochrane Central Register of Controlled Trials. Full-text manuscripts published over more than 35 years, from 1980 to April 2016 were reviewed for relevance and reference lists were cross-checked for additional pertinent studies regarding potential NSBB effects, especially focused on those concerned with survival and/or acute kidney injury (AKI).

Discussion

The proposed review will be able to provide valuable evidence to help decision making in the use of NSBB for the treatment of advanced cirrhosis and highlights some limitations in existing evidence to direct future research.

Oral administration of a non-absorbable plant cell-expressed recombinant anti-TNF fusion protein induces immunomodulatory effects and alleviates nonalcoholic steatohepatitis

AIM

To evaluate the immunomodulatory effect of oral administration of PRX-106 in the high-fat diet model.

METHODS

For 22 wk, C57BL/6 HFD-fed mice received daily oral treatments with BY-2 cells expressing recombinant anti-tumor necrosis factor alpha fusion protein (PRX-106). Mice were followed for serum liver enzyme and triglyceride levels, liver histology and intrahepatic and systemic FACS.

RESULTS

The orally administered non-absorbable PRX-106 was biologically active. Altered distribution of CD4+CD25+FoxP3+ between the liver and spleen and an increase in the intrasplenic-to-intrahepatic CD4+CD25+FoxP3+ ratio and a decrease in the intrasplenic-to-intrahepatic CD8+CD25+FoxP3+ ratio were observed. An increase in intrahepatic NKT cells and a decrease in the intrasplenic-to-intrahepatic NKT ratio were noted. Assessment of the CD4-to-CD8 ratios showed sequestration of CD8+ lymphocytes in the liver. These effects were associated with a decrease in serum triglyceride levels, decrease in the aspartate aminotransferase levels, serum glucose levels, and HOMA-IR score. A decrease in hepatic triglycerides content was observed in the high dose-treated mice.

CONCLUSION

Orally administered PRX-106 shows biological activity and exerts an immunomodulatory effect, alleviating liver damage. The data suggest that PRX-106 may provide an oral immunotherapy for nonalcoholic steatohepatitis.

Intestinal flora: Detection methods and research advances

There are a large number of microorganisms in the human intestine, and they play an important role in digestion and absorption, energy metabolism, immune regulation, disease-resistant ability and so on, and are associated with the development of many diseases. The intestinal flora is of important significance for clinical treatment. This review focuses on a variety of molecular biology technologies for intestinal flora research, such as polymerase chain reaction (PCR), PCR-based 16 S rDNA fingerprinting, fluorescence in situ hybridization, gene chip, metagenome sequencing and so on, as well as the prospects for the research of intestinal flora.

Oral immune therapy: targeting the systemic immune system via the gut immune system for the treatment of inflammatory bowel disease

Inflammatory bowel diseases (IBD) are associated with an altered systemic immune response leading to inflammation-mediated damage to the gut and other organs. Oral immune therapy is a method of systemic immune modulation via alteration of the gut immune system. It uses the inherit ability of the innate system of the gut to redirect the systemic innate and adaptive immune responses. Oral immune therapy is an attractive clinical approach to treat autoimmune and inflammatory disorders. It can induce immune modulation without immune suppression, has minimal toxicity and is easily administered. Targeting the systemic immune system via the gut immune system can serve as an attractive novel therapeutic method for IBD. This review summarizes the current data and discusses several examples of oral immune therapeutic methods for using the gut immune system to generate signals to reset systemic immunity as a treatment for IBD.

Bacterial Translocation and Sample Contamination in Postmortem Microbiological Analyses

The diagnostic value of postmortem bacteriology has been discussed controversially for decades. In the study herein, contamination during sampling procedures and postmortem translocation were investigated to interpret postmortem microbiology results. One hundred medicolegal autopsy cases in total were included. Radiology, histology, bacteriology, and biochemistry were performed in all cases. Based on all investigation findings, 4 groups of cases were identified: death unrelated to infection, true infections, false positive (contamination during sampling procedures, postmortem translocation and mixed situations), and undetermined. The results of this study indicate that postmortem bacteriology provides useful data supporting infection-related deaths, especially when potentially significant observations are accompanied by consistent autopsy, histology, and biochemistry. Result interpretation requires careful evaluation of number and type of isolated microorganisms.

Progenitor cell expansion and impaired hepatocyte regeneration in explanted livers from alcoholic hepatitis

OBJECTIVE

In alcoholic hepatitis (AH), development of targeted therapies is crucial and requires improved knowledge of cellular and molecular drivers in liver dysfunction. The unique opportunity of using explanted livers from patients with AH having undergone salvage liver transplantation allowed to perform more in-depth molecular translational studies.

DESIGN

We studied liver explants from patients with AH submitted to salvage transplantation (n=16), from patients with alcoholic cirrhosis without AH (n=12) and fragments of normal livers (n=16). Hepatic cytokine content was quantified. Hepatocyte function and proliferation and the presence of hepatic progenitor cells (HPCs) were evaluated by immunohistochemistry, western blot or quantitative PCR. Mitochondrial morphology was evaluated by electron microscopy.

RESULTS

Livers from patients with AH showed decreased cytokine levels involved in liver regeneration (tumour necrosis factor α and interleukin-6), as well as a virtual absence of markers of hepatocyte proliferation compared with alcoholic cirrhosis and normal livers. Electron microscopy revealed obvious mitochondrial abnormalities in AH hepatocytes. Importantly, livers from patients with AH showed substantial accumulation of HPCs that, unexpectedly, differentiate only into biliary cells. AH livers predominantly express laminin (extracellular matrix protein favouring cholangiocyte differentiation); consequently, HPC expansion is inefficient at yielding mature hepatocytes.

CONCLUSIONS

AH not responding to medical therapy is associated with lack of expression of cytokines involved in liver regeneration and profound mitochondrial damage along with lack of proliferative hepatocytes. Expansion of HPCs is inefficient to yield mature hepatocytes. Manoeuvres aimed at promoting differentiation of HPCs into mature hepatocytes should be tested in AH.

TLR4 signaling promotes a COX-2/PGE2/STAT3 positive feedback loop in hepatocellular carcinoma (HCC) cells

Toll-like receptors (TLRs) can be expressed by tumor cells, and each TLR exhibits different biological functions. Evidences showed the activation of some certain TLRs could promote tumor progression. One of which TLR4 has been found to promote hepatocellular carcinoma (HCC) cells proliferation, but the detailed mechanism is still unknown. In the present study, we verified that TLR4 was functionally expressed on HCC cells, and TLR4 agonist lipopolysaccharide (LPS) could stimulate the proliferation and clone formation of HCC cells. Most importantly, we found a COX-2/PGE₂/STAT3 positive feedback loop exists in HCC cells, which could be provoked by TLR4 activation. Consistently, the expression of TLR4, COX-2 and p-STAT3^Y705 was positively correlated with each other in liver tumor tissues from patients with primary HCC. Further investigation demonstrated this loop played a dominant role in TLR4-induced HCC cell proliferation and multidrug resistance (MDR) to chemotherapy. Inhibition of TLR4 or COX-2/PGE₂/STAT3 loop would attenuate LPS-induced inflammation and proliferation of HCC cells, and enhance the sensitivity of HCC cells to chemotherapeutics in vitro. By using a primary HCC model, we observed COX-2/PGE₂/STAT3 loop was significantly blocked in TLR4^−/− mice compared to wild type mice, and there was no obvious tumorgenesis sign in TLR4^−/− mice. Therefore, these findings provided the precise molecular mechanism of TLR4 signaling pathway involved in HCC progress, and suggested that TLR4 may be a promising target for HCC treatment.

Tumor grafting induces changes of gut microbiota in athymic nude mice in the presence and absence of medicinal Gynostemma saponins

Recent findings have revealed that gut microbiota plays a substantial role in modulating diseases such as autism, rheumatoid arthritis, allergies, and cancer that occur at sites distant to the gut. Athymic nude mice have been employed for tumorigenic research for decades; however, the relationships between the gut microbiome and host's response in drug treatment to the grafted tumors have not been explored. In this study, we analyzed the fecal microbiome of nonxenograft and xenograft nude mice treated with phytosaponins from a popular medicinal plant, Gynostemma pentaphyllum (Gp). Analysis of enterobacterial repetitive intergenic consensus (ERIC)-PCR data showed that the microbiota profile of xenograft mice departed from that of the nonxenograft mice. After ten days of treatment with Gp saponins (GpS), the microbiota of the treated mice was closer to the microbiota at Day 0 before the implantation of the tumor. Data obtained from 16S pyrosequencing of fecal samples reiterates the differences in microbiome between the nonxenograft and xenograft mice. GpS markedly increased the relative abundance of Clostridium cocleatum and Bacteroides acidifaciens, for which the beneficial effects on the host have been well documented. This study, for the first time, characterizes the properties of gut microbiome in nude mice responding to tumor implant and drug treatment. We also demonstrate that dietary saponins such as GpS can potentially regulate the gut microbial ecosystem by increasing the number of symbionts. Interestingly, this regulation of the gut ecosystem might, at least in part, be responsible for or contribute to the anticancer effect of GpS.

Abnormal intestinal permeability and microbiota in patients with autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis (AIH) is a chronic, progressive, and immunologically mediated inflammatory liver disorder. The etiology of AIH still remains unknown. The aim of this study was to investigate the changes in intestinal permeability, bacterial translocation, and intestinal microbiome in patients with AIH and to evaluate the correlations of those changes with the stages of the disease.

METHODS

24 patients with autoimmune hepatitis and 8 healthy volunteers were recruited for this study. We assessed (1) the integrity of tight junctions within the gut by immunohistochemical analysis of zona occludens-1 and occludin expression in duodenal biopsy specimens; (2) changes in the enteric microbiome by 16S rDNA quantitative PCR; and (3) the presence of bacterial translocation by the level of lipopolysaccharide (LPS) using ELISA.

RESULTS

Increased intestinal permeability, derangement of the microbiome and bacterial translocation occurred in AIH, which correlated with the severity of the disease.

CONCLUSIONS

Autoimmune hepatitis is associated with leaky gut and intestinal microbiome dysbiosis. The impaired intestinal barrier may play an important role in the pathogenesis of AIH.

[Usefulness of procalcitonin for diagnosing infection in critically ill patients with liver cirrhosis]

OBJECTIVE

To evaluate the usefulness of procalcitonin (PCT) for diagnosing infection in patients with liver cirrhosis admitted to an Intensive Care Unit.

DESIGN

A retrospective study was carried out.

SCOPE

Intensive Care Unit. Versatile, twenty-four beds. Participants Patients with liver cirrhosis admitted to our Intensive Care Unit in the last four years with suspected infection and measurement of PCT.

RESULTS

Among the 255 patients with cirrhosis admitted to our unit, PCT was determined for the differential diagnosis of infection in 69 cases (27%). Three patients were excluded from analysis due to a lack of clinical data. The average stay was 10.6 ± 9.2 days, with a mortality rate of 65%. The origin of cirrhosis was mainly viral (57%) or alcoholic (37%). The Child-Pugh and MELD scores were 9.5 ± 2 and 23 ± 8, respectively. Infection was diagnosed in 54 patients (82%). The most common infection was pneumonia (72%), followed by intraabdominal infections (18%) and bacteremia (5%). In patients without infection, the median PCT concentration was 0.57 ng/ml (range 0.28 to 1.14) versus 2.99 (1.31 to 9.4) in those with infection (p<.001). Diagnostic capacity was maintained in patients with intraabdominal infections. The diagnostic cutoff point was set at 0.8 ng/ml (sensitivity 83%, specificity 75%, AUC 0.82 [0.702-0.93]).

CONCLUSIONS

In patients with liver cirrhosis, PCT is useful for identifying bacterial infections, including intraabdominal processes.

Therapeutic effect of Qingyi decoction in severe acute pancreatitis-induced intestinal barrier injury

AIM: To investigate the effect of Qingyi decoction on the expression of secreted phospholipase A₂ (sPLA₂) in intestinal barrier injury.

METHODS: Fifty healthy Sprague-Dawley rats were randomly divided into control, severe acute pancreatitis (SAP), Qingyi decoction-treated (QYT), dexamethasone-treated (DEX), and verapamil-treated (VER) groups. The SAP model was induced by retrograde infusion of 1.5% sodium deoxycholate into the biliopancreatic duct of the rats. All rats were sacrificed 24 h post-SAP induction. Arterial blood, intestine, and pancreas from each rat were harvested for investigations. The levels of serum amylase (AMY) and diamine oxidase (DAO) were determined using biochemical methods, and serum tumor necrosis factor (TNF)-α level was measured by an enzyme linked immunosorbent assay. Pathologic changes in the harvested tissues were investigated by microscopic examination of hematoxylin and eosin-stained tissue sections. The expressions of sPLA₂ at mRNA and protein levels were detected by reverse transcriptase PCR and Western blot, respectively. A terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay was used to investigate apoptosis of epithelial cells in the intestinal tissues.

RESULTS: Compared to the control group, the expression of sPLA₂ at both the mRNA and protein levels increased significantly in the SAP group (0.36 ± 0.13 vs 0.90 ± 0.38, and 0.16 ± 0.05 vs 0.64 ± 0.05, respectively; Ps < 0.01). The levels of AMY, TNF-α and DAO in serum were also significantly increased (917 ± 62 U/L vs 6870 ± 810 U/L, 59.7 ± 14.3 ng/L vs 180.5 ± 20.1 ng/L, and 10.37 ± 2.44 U/L vs 37.89 ± 5.86 U/L, respectively; Ps < 0.01). The apoptosis index of intestinal epithelial cells also differed significantly between the SAP and control rats (0.05 ± 0.02 vs 0.26 ± 0.06; P < 0.01). The serum levels of DAO and TNF-α, and the intestinal apoptosis index significantly correlated with sPLA₂ expression in the intestine (r = 0.895, 0.893 and 0.926, respectively; Ps < 0.05). The levels of sPLA₂, AMY, TNF-α, and DAO in the QYT, VER, and DEX groups were all decreased compared with the SAP group, but not the control group. Qingyi decoction intervention, however, gave the most therapeutic effect against intestinal barrier damage, although the onset of its therapeutic effect was slower.

CONCLUSION: Qingyi decoction ameliorates acute pancreatitis-induced intestinal barrier injury by inhibiting the overexpression of intestinal sPLA_2. This mechanism may be similar to that of verapamil.

Bacterial translocation and endotoxemia after pringle maneuver in cirrhotic rats

BACKGROUND

Pringle maneuver (Pm) is advocated for the reduction of blood loss during liver surgery, while postoperative infections continue to be a frequent complication after hepatic resection and liver transplantation.

AIM

To investigate the effect of the Pringle maneuver on systemic bacterial translocation and endotoxemia in cirrhotic rats and cirrhotic rats with selective intestinal decontamination.

METHODS

A total of 100 male Sprague-Dawley cirrhotic rats were randomly divided into five equal groups: sham operation, Pm of 10 min, Pm of 20 min, Pm of 30 min, and pretreatment. Tissue samples from mesenteric lymph nodes, liver, lungs, portal, and vena cava vein blood were obtained for culture after 30 min and 24 h of the operation. Endotoxin levels were measured in portal vein and vena cava blood.

RESULTS

Portal vein and vena cava blood endotoxin concentrations increased significantly after 30 min, especially 24 h of operation in the Pm of 20 min and Pm of 30 min groups. A significant increase in contaminated mesenteric lymph nodes, liver, portal, and vena cava blood was noted 24 h later. The incidence of gut bacterial translocation increased with the duration extension of Pm. Escherichia coli was the most common bacteria isolated from the tissues. There was a significant decrease of portal vein and vena cava blood endotoxin concentrations and the incidence of bacterial translocation by selective intestinal decontamination.

CONCLUSIONS

There is endotoxemia immediately after Pringle maneuver and gut bacteria translocation 24 h later. The incidence of gut bacterial translocation increases with the duration extension of Pm. Selective intestinal decontamination can decrease bacteria translocation and endotoxemia.

Absent in melanoma 2 triggers a heightened inflammasome response in ascitic fluid macrophages of patients with cirrhosis

BACKGROUND & AIMS

Inflammation is a common event in the pathogenesis of liver cirrhosis. The inflammasome pathway has acquired significant relevance in the pathogenesis of inflammation, but its role in the inflammatory response in patients with decompensated cirrhosis remains unexplored.

METHODS

We performed a prospective study in which 44 patients with decompensated cirrhosis and 12 healthy volunteers were included. We isolated macrophages from blood and ascitic fluid and assessed the expression and activation of the inflammasome, its response to priming by bacterial products, and its association with the degree of liver disease.

RESULTS

Macrophages from sterile ascitic fluids showed constitutive activation of caspase-1 and a marked increase in the expression of IL-1β, IL-18, and absent in melanoma 2 (AIM2) when compared to blood macrophages. Pre-stimulation of blood-derived macrophages from cirrhotic patients with bacterial DNA increased the expression of AIM2 and induced a higher AIM2-mediated inflammasome response than priming with other bacterial products such as lipopolysaccharide. By contrast, activation of the AIM2 inflammasome did not require a priming signal in ascitic fluid-derived macrophages, demonstrating the preactivated state of the inflammasome in these cells. Last, higher IL-1β and IL-18 production by ascitic fluid macrophages correlated with a more advanced Child-Pugh score.

CONCLUSIONS

The inflammasome is highly activated in the ascitic fluid of cirrhotic patients, which may explain the exacerbated inflammatory response observed in these patients under non-infected conditions. Clinically, activation of the inflammasome is associated with a higher degree of liver disease.

Compositional dynamics of the human intestinal microbiota with aging: implications for health

The human gut contains trillions of microbes which form an essential part of the complex ecosystem of the host. This microbiota is relatively stable throughout adult life, but may fluctuate over time with aging and disease. The gut microbiota serves a number of functions including roles in energy provision, nutrition and also in the maintenance of host health such as protection against pathogens. This review summarizes the age-related changes in the microbiota of the gastrointestinal tract (GIT) and the link between the gut microbiota in health and disease. Understanding the composition and function of the gut microbiota along with the changes it undergoes overtime should aid the design of novel therapeutic strategies to counteract such alterations. These strategies include probiotic and prebiotic preparations as well as targeted nutrients, designed to enrich the gut microbiota of the aging population.

Compositional dynamics of the human intestinal microbiota with aging: implications for health

The human gut contains trillions of microbes which form an essential part of the complex ecosystem of the host. This microbiota is relatively stable throughout adult life, but may fluctuate over time with aging and disease. The gut microbiota serves a number of functions including roles in energy provision, nutrition and also in the maintenance of host health such as protection against pathogens. This review summarizes the age-related changes in the microbiota of the gastrointestinal tract (GIT) and the link between the gut microbiota in health and disease. Understanding the composition and function of the gut microbiota along with the changes it undergoes overtime should aid the design of novel therapeutic strategies to counteract such alterations. These strategies include probiotic and prebiotic preparations as well as targeted nutrients, designed to enrich the gut microbiota of the aging population.

The role of the gut microbiome in the development and progression of liver cirrhosis and hepatocellular carcinoma

Liver cirrhosis and hepatocellular carcinoma (HCC) represent the endstage of most chronic liver diseases and are a major global health burden. It has been consistently shown that both liver cirrhosis and HCC are triggered by inflammatory processes, but the molecular mechanisms linking chronic hepatitis with cirrhosis and HCC are only poorly understood. Recent studies suggested that the intestinal microflora as a main source of portal-vein LPS might play a critical role in this process. Here we summarize the available literature on the role of the gut microbiome in hepatofibrogenesis and -carcinogenesis. Such knowledge might help to develop novel, innovative strategies for the prevention and therapy of liver disease.

Risk factors of cellulitis in cirrhosis and antibiotic prophylaxis in preventing recurrence

BACKGROUND

Cellulitis is a commonly encountered bacterial infection among cirrhotic patients apart from spontaneous bacterial peritonitis, urinary tract and respiratory infections. This study aimed to determine the risk factors of cellulitis in cirrhosis and whether antibiotic prophylaxis helps prevent recurrence of cellulitis.

METHODS

The study was conducted in two phases. In phase 1, all cirrhotic patients admitted with cellulitis from August 2011 to August 2013 were taken as cases (n=70) and cirrhotic patients without cellulitis were included as controls (n=73). Baseline demographic data, comorbidities and investigations were noted and compared. In phase 2, the cases of phase 1 were divided into two groups, based on initiation of antibiotic prophylaxis at the time of discharge and were followed up for six months for recurrence of cellulitis.

RESULTS

The main etiology of cirrhosis was alcohol and 68% of cases were Child C. Factors which showed significance in univariate analysis were presence of diabetes mellitus, hepatic encephalopathy, platelet count, albumin level and model for end-stage liver disease (MELD) score. Using logistic regression, hepatic encephalopathy (OR 2.95, CI 1.01-8.45), albumin level <2.5 g/dL (OR 2.80, CI 1.32-5.92) and MELD >15 (OR 2.95, CI 1.39-6.27) emerged as significant factors associated with cellulitis. Cellulitis recurred in 20% and recurrence was significantly low among antibiotic prophylaxis group (15% vs. 50% P=0.048).

CONCLUSIONS

Hypoalbuminemia, and high MELD score are the risk factors for cellulitis in cirrhosis. Antibiotic prophylaxis can reduce the recurrence of cellulitis as in the case of spontaneous bacterial peritonitis.

The gut microbiota and the liver: implications for clinical practice

While a central role for the microbiota in the precipitation of infectious and non-infectious complications of liver disease has been long established, evidence for a more fundamental role in the etiology of several liver diseases continues to accumulate. However, though progress is rapidly occurring in this area, the definitive delineation of the precise relevance of changes in the microbiota to various forms and stages of liver disease is still far from complete. While high quality clinical evidence supports the use of antibiotic therapy, in the management of hepatic encephalopathy, spontaneous bacterial peritonitis and other infectious complications, how these interventions impact on the microbiota and microbiota-host interactions has not been clearly defined. Although probiotics and even, perhaps, fecal transplantation hold promise in the management of liver disease, and the potential impact of probiotics is supported by a considerable amount of laboratory data, high-quality clinical evidence is scanty.

Symbiotic formulation in experimentally induced liver fibrosis in rats: intestinal microbiota as a key point to treat liver damage?

AIM

Evidence indicates that intestinal microbiota may participate in both the induction and the progression of liver damage. The aim of our research was the detection and evaluation of the effects of chronic treatment with a symbiotic formulation on CCl4 -induced rat liver fibrosis.

RESULTS

CCl4 significantly increased gastric permeability in respect to basal values, and the treatment with symbiotic significantly decreased it. CCl4 per se induced a decrease in intestinal permeability. This effect was also seen in fibrotic rats treated with symbiotic and was still evident when normal rats were treated with symbiotic alone (P < 0.001 in all cases). Circulating levels of pro-inflammatory cytokine TNF-α were significantly increased in rats with liver fibrosis as compared with normal rats, while symbiotic treatment normalized the plasma levels of TNF-α and significantly enhanced anti-inflammatory cytokine IL 10. TNF-α, TGF-β, TLR4, TLR2, iNOS and α-SMA mRNA expression in the liver were up-regulated in rats with CCl4 -induced liver fibrosis and down-regulated by symbiotic treatment. Moreover, IL-10 and eNOS mRNA levels were increased in the CCL4 (+) symbiotic group. Symbiotic treatment of fibrotic rats normalized serum ALT, AST and improved histology and liver collagen deposition. DGGE analysis of faecal samples revealed that CCl4 administration and symbiotic treatment either alone or in combination produced modifications in faecal profiles vs controls.

CONCLUSIONS

Our results provide evidence that in CCl4 -induced liver fibrosis, significant changes in gastro-intestinal permeability and in faecal flora occur. Treatment with a specific symbiotic formulation significantly affects these changes, leading to improvement in both liver inflammation and fibrosis.

The great escape: microbiotal LPS takes a toll on the liver

The interaction between the intestinal microbiota and host is much more complex than previously appreciated, and we are now learning that it can have an impact on extraintestinal human diseases. In this issue of the journal (beginning on page 1090), Lin and colleagues present important data linking the microbiota, lipopolysaccharide (LPS), and toll-like receptor (TLR)4 with hepatitis in a mouse model. These provocative results and those from other recent studies highlight the microbiota as a potential target for therapeutic intervention in several liver diseases.

Immune therapy for nonalcoholic steatohepatitis: are we there yet?

Metabolic syndrome, obesity, and nonalcoholic steatohepatitis are associated with a state of chronic inflammation. The immune system and the inflammatory cascade can be involved in the development of any of the above common conditions. This association raises the question of whether immune therapy can be used for the treatment of nonalcoholic steatohepatitis. Although immune therapy is not yet feasible for clinical use, here, we review some of the recent data on the potential role of the various arms of the immune system in the development of nonalcoholic steatohepatitis and several potential therapeutic targets.