Microbiota, NASH, HCC and the potential role of probiotics

Potential Target Metabolites From Gut Microbiota Against Hepatocellular Carcinoma: A Network Pharmacology and Molecular Docking Study

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide, posing significant challenges and economic burdens on healthcare systems. Gut microbiota metabolites have shown promise in cancer treatment, but the specific active metabolites and their key targets remain unclear. This study employed a network pharmacology-based approach to identify potent metabolites of gut microbiota and their key targets. Active metabolites produced by gut microbiota were retrieved using the database gutMGene, and targets associated with these metabolites were identified using the Swiss Target Prediction tool. HCC-related targets were obtained from the GeneCards database, and overlapping targets were selected through a Venn diagram tool. An integrated metabolites-target-pathway network was analyzed to identify active inhibitors against HCC, including p-cresol glucuronide, secoisolariciresinol, glycocholic acid, enterodiol, and citric acid. Molecular docking tests were performed to validate the findings and assess the binding affinity of the metabolites with their target proteins. The study identified AKT1, EGFR, ALB, and TNF genes as potential therapeutic targets against hepatic cancer. The metabolites, p-cresol glucuronide, secoisolariciresinol, glycocholic acid, enterodiol, and citric acid, exhibited significant binding affinity with their respective target proteins. The study also revealed multiple signaling pathways and biological processes associated with the metabolites, demonstrating their preventive effect against HCC. This research utilizes a network pharmacology-based approach to identify potent metabolites of gut microbiota and their key targets for the treatment of HCC. The findings were validated through molecular docking tests, providing a foundation for future studies on anti-HCC metabolites and their mechanisms of action. Furthermore, this study offers insights into the development of novel anti-HCC drugs utilizing gut microbiota metabolites.

Impact of gut microbiota on metabolic dysfunction-associated steatohepatitis and hepatocellular carcinoma: pathways, diagnostic opportunities and therapeutic advances

Metabolic dysfunction-associated steatohepatitis (MASH) and progression to hepatocellular carcinoma (HCC) exhibits distinct molecular and immune characteristics. These traits are influenced by multiple factors, including the gut microbiome, which interacts with the liver through the "gut-liver axis". This bidirectional relationship between the gut and its microbiota and the liver plays a key role in driving various liver diseases, with microbial metabolites and immune responses being central to these processes. Our review consolidates the latest research on how gut microbiota contributes to MASH development and its progression to HCC, emphasizing new diagnostic and therapeutic possibilities. We performed a comprehensive literature review across PubMed/MedLine, Scopus, and Web of Science from January 2000 to August 2024, focusing on both preclinical and clinical studies that investigate the gut microbiota's roles in MASH and HCC. This includes research on pathogenesis, as well as diagnostic and therapeutic advancements related to the gut microbiota. This evidence emphasizes the critical role of the gut microbiome in the pathogenesis of MASH and HCC, highlighting the need for further clinical studies and trials. This is to refine diagnostic techniques and develop targeted therapies that exploit the microbiome's capabilities, aiming to enhance patient care in liver diseases.

Drug regulation of microRNA

The scientific review provides the mechanisms of drug regulation of microRNA in the human body. To write the article, information was searched using Scopus, Web of Science, MEDLINE, PubMed, Google Scholar, Embase, Global Health, The Cochrane Library databases. To restore the reduced functional activity of microRNAs, replacement therapy is used, with modified synthetic analogs of endogenous microRNAs, and drugs that enhance the production of the body’s own microRNAs. The authors state that numerous studies have confirmed the effectiveness of miRNA replacement therapy. It is known that there are several groups of drugs among miRNA inhibitors: anti-miRNA oligonucleotides, miRNA traps, miRNA mimics that prevent miRNA binding; peptide nucleic acids, small-molecule inhibitors. The authors suggest that the expression of drug-metabolizing enzymes is controlled by nuclear receptors and transcription factors, epigenetic regulation such as DNA methylation and histone acetylation, and post-translational modification. It is emphasized that ursodeoxycholic acid modulates the expression of some miRNAs. It is known that probiotic bacteria can modulate the expression level of miRNA genes. The use of probiotics is accompanied by a change in the expression of nume­rous genes of the body involved in the regulation of the inflammatory response, allergic reactions, metabolism and other biological processes. Thus, modern science is intensively studying the potential of using drugs that restore miRNA content or inhibit miRNA acti­vity for the therapy of miRNA-dependent conditions. The results of scientific research confirmed the therapeutic effect of ursodeoxycholic acid and probiotic preparations due to the effect on the acti­vity of miRNA generation in hepatobiliary diseases. Therefore, the introduction into clinical practice of drugs than can modulate the content and expression of specific miRNAs will certainly open new perspectives in the treatment of patients with hepatobiliary diseases.

Nonalcoholic Fatty Liver Disease and the Intestinal Microbiome: An Inseparable Link

Nonalcoholic fatty liver disease (NAFLD) particularly affects patients with type 2 diabetes and obesity. The incidence of NAFLD has increased significantly over the last decades and is now pandemically across the globe. It is a complex systemic disease comprising hepatic lipid accumulation, inflammation, lipotoxicity, gut dysbiosis, and insulin resistance as main features and with the potential to progress to cirrhosis and hepatocellular carcinoma (HCC). In numerous animal and human studies the gut microbiota plays a key role in the pathogenesis of NAFLD, NAFLD-cirrhosis and NAFLD-associated HCC. Lipotoxicity is the driver of inflammation, insulin resistance, and liver injury. Likewise, western diet, obesity, and metabolic disorders may alter the gut microbiota, which activates innate and adaptive immune responses and fuels hereby hepatic and systemic inflammation. Indigestible carbohydrates are fermented by the gut microbiota to produce important metabolites, such as short-chain fatty acids and succinate. Numerous animal and human studies suggested a pivotal role of these metabolites in the progression of NAFLD and its comorbidities. Though, modification of the gut microbiota and/or the metabolites could even be beneficial in patients with NAFLD, NAFLD-cirrhosis, and NAFLD-associated HCC. In this review we collect the evidence that exogenous and endogenous hits drive liver injury in NAFLD and propel liver fibrosis and the progressing to advanced disease stages. NAFLD can be seen as the product of a complex interplay between gut microbiota, the immune response and metabolism. Thus, the challenge will be to understand its pathogenesis and to develop new therapeutic strategies.

Seminars in immunology special issue: Nutrition, microbiota and immunity The unexplored microbes in health and disease

Functional characterization of the microbiome's influence on host physiology has been dominated by a few characteristic example strains that have been studied in detail. However, the extensive development of methods for high-throughput bacterial isolation and culture over the past decade is enabling functional characterization of the broader microbiota that may impact human health. Characterizing the understudied majority of human microbes and expanding our functional understanding of the diversity of the gut microbiota could enable new insights into diseases with unknown etiology, provide disease-predictive microbiome signatures, and advance microbial therapeutics. We summarize high-throughput culture-dependent platforms for characterizing bacterial strain function and host-interactions. We elaborate on the importance of these technologies in facilitating mechanistic studies of previously unexplored microbes, highlight new opportunities for large-scale in vitro screens of host-relevant microbial functions, and discuss the potential translational applications for microbiome science.

Prospects for the use of drugs from the group of agonists of glucagon-like peptide-1 receptors in the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. To a large extent, the development of this disease is associated with metabolic syndrome. There is a pathogenetic association of NAFLD with obesity, type 2 diabetes mellitus (DM2), cardiovascular diseases and chronic kidney disease. Numerous studies demonstrate that an increase in the incidence of NAFLD occurs in parallel with an increase in the prevalence of obesity and DM 2. A number of scientific studies in the field of medicine have made it possible to identify the main pathogenetic mechanisms of the development of the disease, as well as the possibility of using various pharmacological drugs to correct these conditions. Currently, the possibility of using in the future a group of drugs that have a single mechanism for controlling the development of hepatic steatosis, and further progression with the formation of inflammation, cirrhosis and, in some cases, hepatocellular carcinoma, is being considered. Of particular interest is a class of drugs intended for the treatment of type 2 diabetes and obesity – glucagon-like peptide-1 receptor agonists (arGLP-1). A search was made of clinical studies, meta-analyses, literature reviews in databases and registries of medical publications over a period of 10 years. Changes in anthropometric indications, changes in non-invasive markers of liver steatosis, inflammation and fibrosis, as well as histological data on the background of the use of drugs of the arGLP-1 class were studied. It has been demonstrated that the study drug class may have a significant potential for impact on NAFLD. However, further studies with sufficient duration and histological evaluation are needed to fully evaluate the effectiveness of arGLP-1 in the treatment of NAFLD.

Relationships among microbiota, gastric cancer, and immunotherapy

Currently, conventional neoadjuvant therapy or postoperative adjuvant therapy, such as chemotherapy and radiation therapy, can only bring limited survival benefits to gastric cancer (GC). Median survival after palliative chemotherapy is also low, at about 8-10 months. Immunotargeting is a new option for the treatment of GC, but has not been widely replicated. The highly immunosuppressed tumor microenvironment (TME) discounts the efficacy of immunotherapy for GC. Therefore, new strategies are needed to enhance the immune response of the TME. This paper reviewed the relationship between microorganisms and GC, potential links between microorganisms and immunotherapy and research of microorganisms combined immunotherapy.

Relationship between Intestinal Microflora and Hepatocellular Cancer Based on Gut-Liver Axis Theory

The intestinal microflora is a bacterial group that lives in the human digestive tract and has a long-term interdependence with the host. Due to the close anatomical and functional relationship between the liver and the intestine, the intestinal flora affects liver metabolism via the intestinal-hepatic circulation, thereby playing an extremely important role in the pathological process of liver inflammation, chronic fibrosis, and liver cancer. In recent years, the rapid development of technologies in high-throughput sequencing and genomics has opened up possibilities for a broader and deeper understanding of the crosstalk between the intestinal flora and the occurrence and development of liver cancer. This review aims to summarize the mechanisms by which the gut microbiota changes the body's metabolism, through the gut-liver axis, thereby affecting the occurrence and development of primary liver cancer. In addition, the potential regulation of intestinal microflora in the treatment of liver cancer is discussed.

Effects of Probiotic Supplementation during Pregnancy on the Future Maternal Risk of Metabolic Syndrome

Probiotics are live microorganisms that induce health benefits in the host. Taking probiotics is generally safe and well tolerated by pregnant women and their children. Consumption of probiotics can result in both prophylactic and therapeutic effects. In healthy adult humans, the gut microbiome is stable at the level of the dominant taxa: Bacteroidetes, Firmicutes and Actinobacteria, and has a higher presence of Verrucomicrobia. During pregnancy, an increase in the number of Proteobacteria and Actinobacteria phyla and a decrease in the beneficial species Roseburia intestinalis and Faecalibacterium prausnitzii are observed. Pregnancy is a "window" to the mother's future health. The aim of this paper is to review studies assessing the potentially beneficial effects of probiotics in preventing the development of diseases that appear during pregnancy, which are currently considered as risk factors for the development of metabolic syndrome, and consequently, reducing the risk of developing maternal metabolic syndrome in the future. The use of probiotics in gestational diabetes mellitus, preeclampsia and excessive gestational weight gain is reviewed. Probiotics are a relatively new intervention that can prevent the development of these disorders during pregnancy, and thus, would reduce the risk of metabolic syndrome resulting from these disorders in the mother's future.

Hepatic Steatosis in Patients with Celiac Disease: The Role of Packaged Gluten-Free Foods

Background: An increased risk of nonalcoholic fatty liver disease (NAFLD) in patients with celiac disease (CD) adhering to a gluten-free diet (GFD) was recently reported. The nutritional composition of packaged gluten-free foods (PGFF) has been proposed as a possible cause. This hypothesis has not been investigated further, since a systematic structural nutritional interview for all patients would be problematic in clinical practice. Methods: We administered a simple questionnaire based on a Recency, Frequency, and Monetary value (RFM) analysis (a cornerstone of direct marketing segmentation) to consecutive CD patients on a GFD for >6 months and verified its association with NAFLD. Subgroup analyses were performed to understand whether specific patterns of PGFF consumption were significantly associated with NAFLD. Results: Amongst 147 patients (female 82%, median age 42 years), 45 (30.6%) had NAFLD. Total RFM score (adjusted odds ratio = 1.223, 95% CI: 1.059−1.413, p = 0.006), body mass index, and total cholesterol and triglycerides were independently related to NAFLD, and “Bread and bakery” (p = 0.002), “salty convenience” (p = 0.005), and “sweet convenience” (p = 0.049) products were significantly related with NAFLD. Also, questions about the number of purchased PGFF in the last month (monetary value) and different categories of PGFF consumed in the last week (recency) were particularly able to identify NAFLD patients. Conclusions: The specific GFD dietary habits of CD patients were correlated with the degree of risk of NAFLD. Information was obtained through a questionnaire which could be used in clinical practice to favor a patient-tailored approach and in future studies to verify the reproducibility of our results in different geographical areas.

Effects of Ganfule capsule on microbial and metabolic profiles in anti-hepatocellular carcinoma

AIMS

Based on the gut microbiota and plasma metabolites, the underlying mechanism was analysed for the anti-hepatocellular carcinoma (HCC) effects of Ganfule capsule (GFL) in the study.

METHODS AND RESULTS

The UPLC-Q-TOF/MS results showed that 13 key compounds were identified in GFL and the major active ingredients included amygdalin, saikosaponin A, astragaloside I, etc. The nude mice received HepG2 injection, and GFL showed lower volume and weight of the tumour. In addition, the apoptosis proteins (Bax and Bcl2) were altered in response to GFL treatment, and apoptosis cells were increased, indicating an anti-HCC effect. Interestingly, 16S rDNA results showed that GFL treatment improved gut microbiota diversity and compositions, especially for the beneficial bacteria, such as Bacilli, Lactobacillales, Lactobacillus, Lactobacillaceae, Firmicutes, Lactobacillus_reuteri and Lactobacillus_gasseri. Metabonomics further identified 426 metabolites and 343 metabolites variation in the positive and negative ion modes after GFL treatment, which might be associated with amino acid, lipid metabolism and carbohydrate metabolism pathways, indicating these metabolites might involve in the protective role of GFL in HCC. Correlation analysis showed a significant relationship between gut microbiota and plasma metabolites.

CONCLUSION

In conclusion, GFL exerted an anti-HCC effect in the nude murine model, which might be associated with microbial and metabolic improvements.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first to report the anti-HCC effect of GFL associated with gut microbiota and plasma metabolites. GFL may improve the gut microbiota structure, such as increasing probiotics - Lactobacillus. It also provides a new strategy for the scientific demonstration of the modernization of traditional Chinese medicine.

Fecal Microbiota Transplantation Controls Progression of Experimental Autoimmune Hepatitis in Mice by Modulating the TFR/TFH Immune Imbalance and Intestinal Microbiota Composition

Intestinal microbiota (IM) dysbiosis contributes to the development of autoimmune hepatitis (AIH). This study aimed to investigate the potential effect of fecal microbiota transplantation (FMT) in a murine model of experimental AIH (EAH), a condition more similar to that of AIH patients. Changes in the enteric microbiome were determined in AIH patients and EAH mice. Moreover, we established an experimental model of secondary EAH mice harboring dysbiosis (ABx) to analyze the effects of therapeutic FMT administration on follicular regulatory T (TFR) and helper T (TFH) cell imbalances and IM composition in vivo. Alterations of the IM composition and bacterial translocation occurred in AIH patients compared to nonalcoholic fatty liver disease patients and healthy controls (HCs). Therapeutic FMT significantly attenuated liver injury and bacterial translocation and improved the imbalance between splenic TFR cells and TFH cells in ABx EAH mice. Furthermore, therapeutic FMT also partially reversed the increasing trend in serum liver enzymes (ALT and AST) of CXCR5-/-EAH mice on the 28th day. Finally, therapeutic FMT could effectively restore antibiotic-induced IM dysbiosis in EAH mice. Taken together, our findings demonstrated that FMT was capable of controlling hepatitis progression in EAH mice, and the associated mechanism might be involved in the regulation of the TFR/TFH immune imbalance and the restoration of IM composition.

Role of microbiota-derived short-chain fatty acids in cancer development and prevention

Following cancer, cells in a particular tissue can no longer respond to the factors involved in controlling cell survival, differentiation, proliferation, and death. In recent years, it has been indicated that alterations in the gut microbiota components, intestinal epithelium, and host immune system are associated with cancer incidence. Also, it has been demonstrated that the short-chain fatty acids (SCFAs) generated by gut microbiota are vitally crucial in cell homeostasis as they contribute to the modulation of histone deacetylases (HDACs), resulting effected cell attachment, immune cell immigration, cytokine production, chemotaxis, and the programmed cell death. Therefore, the manipulation of SCFA levels in the intestinal tract by alterations in the microbiota structure can be potentially taken into consideration for cancer treatment/prevention. In the current study, we will explain the most recent findings on the detrimental or protective roles of SFCA (particularly butyrate, propionate, and acetate) in several cancers, including bladder, colon, breast, stomach, liver, lung, pancreas, and prostate cancers.

Gut Microbiota And Inflammatory Disorders

The gut has been colonized with bacteria, fungi, viruses, archaea, eukarya. The human and bacterial cells are found in a 1:1 ratio, while the variance in the diversity of gut microbiota may result in Dysbiosis. Gut dysbiosis may result in various pathological manifestations. Beneficial gut microbiota may synthesize short-chain fatty acids like acetate, butyrate, propionate, while -gram-negative organisms are the primary source of LPS, a potent pro-inflammatory mediator. Both gut microbiota and microbial products may be involved in immunomodulation as well as inflammation. Prebiotics and probiotics are being explored as therapeutic agents against various inflammatory and autoimmune disorders. Here we discuss the molecular mechanisms involved in gut bacteria-mediated modulation of various inflammatory and autoimmune disorders.

Diet-Regulating Microbiota and Host Immune System in Liver Disease

The gut microbiota has been known to modulate the immune responses in chronic liver diseases. Recent evidence suggests that effects of dietary foods on health care and human diseases are related to both the immune reaction and the microbiome. The gut-microbiome and intestinal immune system play a central role in the control of bacterial translocation-induced liver disease. Dysbiosis, small intestinal bacterial overgrowth, translocation, endotoxemia, and the direct effects of metabolites are the main events in the gut-liver axis, and immune responses act on every pathways of chronic liver disease. Microbiome-derived metabolites or bacteria themselves regulate immune cell functions such as recognition or activation of receptors, the control of gene expression by epigenetic change, activation of immune cells, and the integration of cellular metabolism. Here, we reviewed recent reports about the immunologic role of gut microbiotas in liver disease, highlighting the role of diet in chronic liver disease.

Mechanisms by Which Probiotic Bacteria Attenuate the Risk of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the second leading cause of cancer-related deaths worldwide. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV), alcoholic liver disease (ALD), and non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) are the major extrinsic risk factors of HCC development. Genetic background is pivotal in HCC pathogenesis, and both germline mutations and single nucleotide polymorphism (SNP) are intrinsic risk factors of HCC. These HCC risk factors predispose to hepatic injury and subsequent activation of fibrogenesis that progresses into cirrhosis and HCC. Probiotic bacteria can mitigate HCC risk by modulating host gut microbiota (GM) to promote growth of beneficial microbes and inhibit HCC-associated dysbiosis, thus preventing pathogen-associated molecular patterns (PAMPs)-mediated hepatic inflammation. Probiotics have antiviral activities against HBV and HCV infections, ameliorate obesity and risk of NAFLD/NASH, and their antioxidant, anti-proliferative, anti-angiogenic, and anti-metastatic effects can prevent the HCC pathogenesis. Probiotics also upregulate the expression of tumor suppressor genes and downregulate oncogene expression. Moreover, metabolites generated by probiotics through degradation of dietary phytochemicals may mitigate the risk of HCC development. These multiple anticancer mechanisms illustrate the potential of probiotics as an adjuvant strategy for HCC risk management and treatment.

Gastrointestinal cancers: the role of microbiota in carcinogenesis and the role of probiotics and microbiota in anti-cancer therapy efficacy

The gut epithelium is a habitat of a variety of microorganisms, including bacteria, fungi, viruses and Archaea. With the advent of sophisticated molecular techniques and bioinformatics tools, more information on the composition and thus function of gut microbiota was revealed. The gut microbiota as an integral part of the intestinal barrier has been shown to be involved in shaping the mucosal innate and adaptive immune response and to provide protection against pathogens. Consequently, a set of biochemical signals exchanged within microbes and communication between the microbiota and the host have opened a new way of thinking about cancer biology. Probiotics are living organisms which administered in adequate amounts may bring health benefits and have the potential to be an integral part of the prevention/treatment strategies in clinical approaches. Here we provide a comprehensive review of data linking gut microbiota to cancer pathogenesis and its clinical course. We focus on gastrointestinal cancers, such as gastric, colorectal, pancreatic and liver cancer.

Increased risk of acute liver failure by pain killer drugs in NAFLD: Focus on nuclear receptors and their coactivators

Non-alcoholic fatty liver disease (NAFLD) is a global condition characterized by an accumulation of lipids in the hepatocytes. NAFLD ranges from simple steatosis, a reversible and relatively benign condition, to fibrosis with non-alcoholic steatohepatitis (NASH), potentially leading to cirrhosis and hepatocarcinoma. NAFLD can increase the susceptibility to severe liver injury with eventual acute liver failure induced by specific hepatotoxic drugs, including acetaminophen (APAP), which is commonly used as analgesic and antipyretic. Although several animal models have been used to clarify the predisposing role of hepatic steatosis to APAP intoxication, the exact mechanism is still not clear. Here, we shed a light into the association between NAFLD and APAP toxicity by examining the peculiar role of nuclear receptor peroxisome proliferator-activated receptor α (PPARα) and coactivator peroxisome proliferator-activated receptor gamma coactivator 1-β (PGC-1β) in driving fatty acid metabolism, inflammation and mitochondria redox balance. The knowledge of the mechanism that exposes patients with NAFLD to higher risk of acute liver failure by pain killer drug is the first step to eventually claim for a reduction of the maximal diurnal dose of APAP for subjects with liver steatosis.

Research progress of intestinal microecology in the occurrence and development of precancerous lesions of liver

Intestinal microecology refers to the interaction between the host and the microorganisms in the human intestinal tract, which is composed mainly of intestinal flora. Intestinal microflora affects the physiological and pathological changes of the host through metabolic activity and host interaction. Precancerous lesion of liver is a potential benign liver disease, which may lead to malignant transformation of liver. It is the intermediate stage from benign lesion to malignant transformation. Recent studies have shown that intestinal microecology is closely related to the occurrence of precancerous lesions of the liver. This study expounds the interaction of the bridge between intestine and liver, the gutliver axis, the intestinal microecology and the precancerous lesions of liver, hoping to provide a new idea for clinical prevention and treatment of precancerous lesions of liver.

Post-hoc analysis of a randomized controlled trial on the impact of pre-transplant use of probiotics on outcomes after liver transplantation

Perioperative use of probiotics serves as efficient prophylaxis against postoperative infections after liver transplantation, yet data on long-term effects of pre-transplant probiotic intake is lacking. The aim of this study was to assess the effects of pre-transplant probiotic administration on long-term results of liver transplantation. This was secondary analysis of a randomized trial. Patients were randomized to receive either 4-strain probiotic or placebo before liver transplantation. Five year graft survival was set as the primary end-point. Secondary end-points comprised serum bilirubin and C-reactive protein (CRP) concentration, international normalized ratio (INR), serum transaminases and gamma-glutamyl transferase (GGT) activity. Study group comprised 44 patients, of whom 21 received probiotics and 23 received placebo with 5-year graft survival of 81.0% and 87.0%, respectively (p = 0.591). Patients in the probiotic arm exhibited lower INR (p = 0.001) and CRP (p = 0.030) over the first 6 post-transplant months. In the absence of hepatitis B or C virus infection, pre-transplant administration of probiotics also reduced aspartate transaminase activity (p = 0.032). In the intervention arm, patients receiving probiotics for under and over 30 days had 5-year graft survival rates of 100% and 66.7%, respectively (p = 0.061). Duration of probiotic intake > 30 days was additionally associated with increased INR (p = 0.031), GGT (p = 0.032) and a tendency towards increased bilirubin (p = 0.074) over first 6 post-transplant months. Pre-transplant administration of probiotics has mild positive influence on 6-month allograft function, yet should not exceed 30 days due to potential negative effects on long-term outcomes. (ClinicalTrials.gov Identifier: NCT01735591).

Non-Alcoholic Steatohepatitis as a Risk Factor for Intrahepatic Cholangiocarcinoma and Its Prognostic Role

Non-alcoholic fatty liver disease (NAFLD) and its most aggressive form, non-alcoholic steatohepatitis (NASH), are causing a rise in the prevalence of hepatocellular carcinoma. Data about NAFLD/NASH and intrahepatic cholangiocarcinoma (iCCA) are few and contradictory, coming from population registries that do not correctly distinguish between NAFLD and NASH. We evaluated the prevalence of NAFLD and NASH in peritumoral tissue of resected iCCA (n = 180) and in needle biopsies of matched liver donors. Data of iCCA patients were subsequently analysed to compare NASH-related iCCA (Group A), iCCA arisen in a healthy liver (Group B) or in patients with classical iCCA risk factors (Group C). NASH was found in 22.5% of 129 iCCA patients without known risk factors and in 6.2% of matched controls (risk ratio 3.625, 95% confidence interval 1.723-7.626, p < 0.001), while NAFLD was equally represented in both groups. The overall survival of NASH-related iCCA was inferior to that of patients with healthy liver (38.5 vs. 48.1 months, p = 0.003) and similar to that of patients with known risk factors (31.9 months, p = 0.948), regardless of liver fibrosis. The multivariable Cox regression confirmed NASH as a prognostic factor (hazard ratio 1.773, 95% confidence interval 1.156-2.718, p = 0.009). We concluded that NASH (but not NAFLD) is a risk factor for iCCA and might affect its prognosis. Dissecting NASH from NAFLD by histology is necessary to correctly assess the actual role of these conditions. Prevention protocols for NASH patients should also consider the risk for iCCA and not only HCC. Mechanistic studies aimed to find a direct pathogenic link between NASH and iCCA could add further relevant information.

Hepatocellular carcinoma in patients with non-alcoholic steatohepatitis - epidemiology, risk factors, clinical implications and treatment

In recent years, rapid growth of incidence of metabolic syndrome, obesity and diabetes has been noted worldwide. Concurrent non-alcoholic steatohepatitis (NASH) has become a dominant factor of hepatic cirrhosis and hepatocellular carcinoma (HCC). The most important risk factors of transition from NASH to HCC are the degree of liver fibrosis, diabetes, obesity, age and male gender. Body mass index (BMI) reduction and increase of physical activity limit the risk of occurrence of HCC. Also, treatment of diabetes with metformin and application of statins have potential anticancer effects. Patients with HCC due to NASH should be treated in line with BCLC staging. Distant results of HCC therapy in the course of non-alcoholic fatty liver disease (NAFLD) are similar to the results of cancer of different aetiologies. However, patients with the metabolic syndrome are at high perioperative risk, and thus require accurate preparation, especially cardiological, in order to avoid that risk.

Liver cirrhosis contributes to the disorder of gut microbiota in patients with hepatocellular carcinoma

Background

Gut microbiota (GM) of patients with liver cancer is disordered, and syet no study reported the GM distribution of liver cirrhosis‐induced HCC (LC‐HCC) and nonliver cirrhosis‐induced HCC (NLC‐HCC). In this study, we aimed to characterize gut dysbiosis of LC‐HCC and NLC‐HCC to elucidate the role of GM in the pathogenesis of HCC.

Methods

A consecutive series of fecal samples of patients with hepatitis (24 patients), liver cirrhosis (24 patients), HCC (75 patients: 35 infected by HBV, 25 infected by HCV, and 15 with alcoholic liver disease), and healthy controls (20 patients) were obtained and sequenced on the Illumina Hiseq platform. The HCC group contains 52 LC‐HCC and 23 NLC‐HCC. Bioinformatic analysis of the intestinal microbiota was performed with QIIME and MicrobiomeAnalyst.

Results

Alpha‐diversity analysis showed that fecal microbial diversity was significantly decreased in the LC group, and there were significant differences in 3 phyla and 27 genera in the LC group vs the other groups (the healthy, hepatitis, and HCC groups). Beta‐diversity analysis showed that there were large differences between LC and the others. Gut microbial diversity was significantly increased from LC to HCC. Characterizing the fecal microbiota of LC‐HCC and NLC‐HCC, we found that microbial diversity was increased from LC to LC‐HCC rather than NLC‐HCC. Thirteen genera were discovered to be associated with the tumor size of HCC. Three biomarkers (Enterococcus, Limnobacter, and Phyllobacterium) could be used for precision diagnosis. We also found that HBV infection, HCV infection, or ALD (alcoholic liver disease) was not associated with intestinal microbial dysbiosis in HCC.

Conclusion

Our results suggest that GM disorders are more common in patients with LC‐HCC. The butyrate‐producing genera were decreased, while genera producing‐lipopolysaccharide (LPS) were increased in LC‐HCC patients. Further studies of GM disorders may achieve early diagnosis and new therapeutic approaches for HCC patients.

Bile acid receptors FXR and TGR5 signaling in fatty liver diseases and therapy

Bile acid synthesis is the most significant pathway for catabolism of cholesterol and for maintenance of whole body cholesterol homeostasis. Bile acids are physiological detergents that absorb, distribute, metabolize, and excrete nutrients, drugs, and xenobiotics. Bile acids also are signal molecules and metabolic integrators that activate nuclear farnesoid X receptor (FXR) and membrane Takeda G protein-coupled receptor 5 (TGR5; i.e., G protein-coupled bile acid receptor 1) to regulate glucose, lipid, and energy metabolism. The gut-to-liver axis plays a critical role in the transformation of primary bile acids to secondary bile acids, in the regulation of bile acid synthesis to maintain composition within the bile acid pool, and in the regulation of metabolic homeostasis to prevent hyperglycemia, dyslipidemia, obesity, and diabetes. High-fat and high-calorie diets, dysbiosis, alcohol, drugs, and disruption of sleep and circadian rhythms cause metabolic diseases, including alcoholic and nonalcoholic fatty liver diseases, obesity, diabetes, and cardiovascular disease. Bile acid-based drugs that target bile acid receptors are being developed for the treatment of metabolic diseases of the liver.

Hepatocellular carcinoma in the context of non-alcoholic steatohepatitis (NASH): recent advances in the pathogenic mechanisms

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. HCC is particularly aggressive and is one of the leading causes of cancer mortality. In recent decades, the epidemiological landscape of HCC has undergone significant changes. While chronic viral hepatitis and excessive alcohol consumption have long been identified as the main risk factors for HCC, non-alcoholic steatohepatitis (NASH), paralleling the worldwide epidemic of obesity and type 2 diabetes, has become a growing cause of HCC in the US and Europe. Here, we review the recent advances in epidemiological, genetic, epigenetic and pathogenic mechanisms as well as experimental mouse models that have improved the understanding of NASH progression toward HCC. We also discuss the clinical management of patients with NASH-related HCC and possible therapeutic approaches.

Hepatocellular carcinoma in non-alcohol fatty liver disease - changing trends and specific challenges

Background and Aims: Hepatocellular carcinoma (HCC) is the most common primary liver cancer. The etiology of this disease is known in 90% of the patients, and it is viral in most of the cases. According to recent predictions, nearly half of the world population will be suffering from obesity by 2030. Consequently, non-alcoholic fatty liver disease (NAFLD) may play a growing role in HCC epidemiology. In this review, we sought to explore the relationship between liver steatosis and HCC.Methods: A narrative review was conducted using the PubMed MeSH search. The eligible papers were identified using a standard PubMed search with relevant key terms and various synonyms.Results: According to the results, patients with NAFLD-HCC tended to be older than those with hepatitis C virus (HCV)-HCC, and they were more often obese and had concomitant diseases, such as diabetes. On the other hand, the synthetic liver function was better preserved in NAFLD-HCC patients, who also obtained lower scores on the Model for End-stage Liver Disease (MELD) and Child-Turcotte-Pugh (CTP). However, it has to be noted that HCC in patients with non-alcoholic steatohepatitis (NASH) may develop without underlying cirrhosis. Although NASH-HCC is usually smaller and well-differentiated compared to HCV-HCC, the prognosis is similar in both groups. Efficient HCC screening in NASH cirrhosis poses a challenge because it is difficult to perform ultrasound examination in obese patients and alfa-fetoprotein level is no longer considered reliable.Conclusions: The constantly increasing prevalence of NAFLD in the general population can contribute to a growing role of NAFLD/NASH in HCC epidemiology. Moreover, some particular challenges specific for patients with liver steatosis may impede proper HCC diagnosis, treatment and follow-up.

Gut microbiota: A new piece in understanding hepatocarcinogenesis

The gut microbiota forms a symbiotic relationship with the host and benefits the body in many critical aspects of life. However, immune system defects, alterations in the gut microbiota and environmental changes can destroy this symbiotic relationship and may lead to diseases, including cancer. Due to the anatomic and functional connection of the gut and liver, increasing studies show the important role of the gut microbiota in the carcinogenesis of hepatocellular carcinoma (HCC). In this manuscript, we review the available evidence and analyze some potential mechanisms of the gut microbiota, including bacterial dysbiosis, lipopolysaccharide (LPS), and genotoxins, in the progression and promotion of HCC. Furthermore, we discuss the possible therapeutic applications of probiotics, chemotherapy modulation, immunotherapy, targeted drugs and fecal microbiota transplantation (FMT) in targeting the gut microbiota.

Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of disease, extending from simple steatosis to inflammation and fibrosis with a significant risk for the development of cirrhosis. It is highly prevalent and is associated with significant adverse outcomes both through liver-specific morbidity and mortality but, perhaps more important, through adverse cardiovascular and metabolic outcomes. It is closely associated with type 2 diabetes and obesity, and both of these conditions drive progressive disease toward the more advanced stages. The mechanisms that govern hepatic lipid accumulation and the predisposition to inflammation and fibrosis are still not fully understood but reflect a complex interplay between metabolic target tissues including adipose and skeletal muscle, and immune and inflammatory cells. The ability to make an accurate assessment of disease stage (that relates to clinical outcome) can also be challenging. While liver biopsy is still regarded as the gold-standard investigative tool, there is an extensive literature on the search for novel noninvasive biomarkers and imaging modalities that aim to accurately reflect the stage of underlying disease. Finally, although no therapies are currently licensed for the treatment of NAFLD, there are interventions that appear to have proven efficacy in randomized controlled trials as well as an extensive emerging therapeutic landscape of new agents that target many of the fundamental pathophysiological processes that drive NAFLD. It is highly likely that over the next few years, new treatments with a specific license for the treatment of NAFLD will become available.

Hepatocellular Carcinoma in Non Alcoholic Fatty Liver Disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a global epidemic involving 20-40% of the general population. NAFLD is rapidly becoming the leading cause of hepatocellular carcinoma (HCC) worldwide. Knowledge about NAFLD-HCC peculiar features is needed to understand this emerging disease better.

OBJECTIVE

To review the current literature about the epidemiological, pathogenic and clinical features characterising the NAFLD and distinguishing it from HCC of other etiologies.

METHODS

A systematic review of the literature (PubMed and Medline) using the following string ("Non-alcoholic Fatty Liver Disease"[Mesh] and "Carcinoma, Hepatocellular"[Mesh]). Particular relevance was given to papers published in the last five years as well as previously published manuscript very relevant to this topic according to the experience of the authors.

RESULTS

A total of 244 original papers in humans in English literature were analysed. Inherent difficulties in the identification of high-risk subjects and the possibility of occurrence in non-cirrhotic livers are peculiar characteristics of NAFLD-HCC hampering surveillance programs. The consequently delayed diagnosis limits access to surgical procedures and impacts on survival. After correction for tumour burden, however, the survival is not different from that of viral HCC, suggesting that NAFLD-HCC is not intrinsically a more aggressive malignancy.

CONCLUSION

A great deal of effort is needed to improve the clinical outcome of NAFLD-HCC, especially in terms of prevention, surveillance protocols, and identification of drug modifying the natural history of the underlying liver disease. The outcome of these efforts will significantly impact global HCC-related costs and mortality.

A Cholecystokinin Receptor Antagonist Halts Nonalcoholic Steatohepatitis and Prevents Hepatocellular Carcinoma

BACKGROUND AND AIMS

Nonalcoholic steatohepatitis (NASH) is a common inflammatory liver condition that may lead to cirrhosis and hepatocellular carcinoma (HCC). Risk factors for NASH include a saturated fat diet, altered lipid metabolism, and genetic and epigenetic factors, including microRNAs. Serum levels of cholecystokinin (CCK) are elevated in mice and humans that consume a high-saturated fat diet. CCK receptors (CCK-Rs) have been reported on fibroblasts which when activated can induce fibrosis; however, their role in hepatic fibrosis remains unknown. We hypothesized that elevated levels of CCK acting on the CCK-Rs play a role in the development of NASH and in NASH-associated HCC.

METHODS

We performed a NASH Prevention study and Reversal study in mice fed a saturated fat 75% choline-deficient-ethionine-supplemented (CDE) diet for 12 or 18 weeks. In each study, half of the mice received untreated drinking water, while the other half received water supplemented with the CCK-R antagonist proglumide. CCK-R expression was evaluated in mouse liver and murine HCC cells.

RESULTS

CCK receptor antagonist treatment not only prevented NASH but also reversed hepatic inflammation, fibrosis, and steatosis and normalized hepatic transaminases after NASH was established. Thirty-five percent of the mice on the CDE diet developed HCC compared with none in the proglumide-treated group. We found that CCK-BR expression was markedly upregulated in mouse CDE liver and HCC cells compared with normal hepatic parenchymal cells, and this expression was epigenetically regulated by microRNA-148a.

CONCLUSION

These results support the novel role of CCK receptors in the pathogenesis of NASH and HCC.

Regulation of Shaoyao Ruangan Mixture on Intestinal Flora in Mice With Primary Liver Cancer

Background: Shaoyao Ruangan mixture (SRM) has been applied clinically for more than 20 years in Zhejiang Cancer Hospital to treat patients with primary liver cancer (PLC). Intestinal microecology plays an important role in the emergence of liver diseases. This study aimed to reveal connections among SRM, intestinal microbiota and PLC, and the potential targets of SRM for liver cancer. Methods: We established a control group, a PLC model group, and a treatment group of mice to analyze the inhibitory effect of SRM on PLC and its intestinal flora target. We also evaluated drug efficacy of SRM and analyzed specific changes in intestinal flora by 16S rDNA sequencing of stools. As the serum interleukin (IL)-10 level could be an independent prognostic factor for unresectable liver cancer, we detected IL-10 levels and analyzed their association with the abundance of specific bacteria. Results: Liver tumors in the treatment group were smaller and fewer than those in the model group (P = .046). The abundance of Bacteroides was significantly higher in the model group than that in the control group, while SRM significantly reduced the increasing abundance of Bacteroides in mice with PLC. We found that the IL-10 level was positively correlated with the abundance of Bacteroides. Conclusion: SRM can effectively inhibit the progression of PLC and increase Bacteroides abundance. In view of the association between Bacteroides and liver cancer and the significant positive correlation between Bacteroides and IL-10 levels, Bacteroides may be the target intestinal flora of SRM to inhibit PLC.

Molecular links between non-alcoholic fatty liver disease and hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD) and its advanced complication, non-alcoholic steatohepatitis (NASH), have become leading causes of hepatocellular carcinoma (HCC) worldwide. In this review, we discuss the role of metabolic, gut microbial, immune and endocrine mediators which promote the progression of NAFLD to HCC. In particular, this progression involves multiple hits resulting from lipotoxicity, oxidative stress, inhibition of hepatic autophagy and inflammation. Furthermore, dysbiosis in the gut associated with obesity also promotes HCC via induction of proinflammatory cytokines and Toll like receptor signalling as well as altered bile metabolism. Additionally, compromised T-cell function and impaired hepatic hormonal action promote the development of NASH-associated HCC. Lastly, we discuss the current challenges involved in the diagnosis and treatment of NAFLD/NASH-associated HCC.

1-Deoxynojirimycin improves high fat diet-induced nonalcoholic steatohepatitis by restoring gut dysbiosis

Non-alcoholic steatohepatitis (NASH) is associated with chronic inflammation and gut bacterial dysbiosis. Studies show that 1-deoxynojirimycin (DNJ) may improve NASH, yet the role of gut microbiota in protective effect of DNJ on NASH remains to be known. In present study, we aimed to examine how DNJ ameliorated high-fat diet (HFD)-induced mouse NASH through the regulation of gut microbiota dysbiosis. C57BL/6 J mice fed with HFD were treated with DNJ (0.1 mg/mL, in drinking water) for 4 months. The results by using histochemical staining and qPCR confirmed that DNJ remarkably modulated glucose intolerance and hyperlipidemia, attenuated hepatic steatosis and systemic chronic inflammation in HFD-induced mice. Moreover, DNJ greatly reshaped the structure of disbalanced intestinal flora, as indicated by the enhanced bacterial richness and diversity, the decreased Firmicutes-to-Bacteroidetess ratio and the increased Akkermansia level. The prediction algorithm suggests that DNJ may extensively dampen the bacterial motility and bacterial energy metabolism. Consistently, the altered gut microbiota was closely correlated with metabolic biomarkers of mice with NASH. Based on our studies, DNJ could alleviate the progress of HFD-induced NASH by rebuilding the gut microbial community structure, suggesting that DNJ may serve as a functional food to prevent or treat NASH clinically.

Microbiota: Overview and Implication in Immunotherapy-Based Cancer Treatments

During the last few years, the gut microbiota has gained increasing attention as a consequence of its emerging role as a modulator of the immune system. With the advent of the era of checkpoint inhibitors immunotherapy and adoptive cell transfer (ACT) in oncology, these findings became of primary relevance in light of experimental data that suggested the microbiota involvement as a plausible predictor of a good or poor response. These remarks justify the efforts to pinpoint the specific actions of the microbiota and to identify new strategies to favorably edit its composition.

Dietary and Pharmacological Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the developed world. Simple hepatic steatosis is mild, but the coexistence of steatohepatitis (NASH) and fibrosis increases the risk of hepatocellular carcinoma. Proper dietary and pharmacological treatment is essential for preventing NAFLD progression. The first-line treatment should include dietary intervention and increased physical activity. The diet should be based on the food pyramid, with a choice of products with low glycemic index, complex carbohydrates in the form of low-processed cereal products, vegetables, and protein-rich products. Usage of insulin-sensitizing substances, pro- and prebiotics, and vitamins should also be considered. Such a therapeutic process is intended to support both liver disease and obesity-related pathologies, including insulin resistance, diabetes, dyslipidemia, and blood hypertension. In the pharmacological treatment of NAFLD, apart from pioglitazone, there are new classes of antidiabetic drugs that are of value, such as glucagon-like peptide 1 analogs and sodium/glucose cotransporter 2 antagonists, while several other compounds that target different pathogenic pathways are currently being tested in clinical trials. Liver biopsies should only be considered when there is a lack of decline in liver enzymes after 6 months of the abovementioned treatment. Dietary intervention is recommended in all patients with NAFLD, while pharmacological treatment is recommended especially for those with NASH and showing significant fibrosis in a biopsy.

Exploring the microbiota to better understand gastrointestinal cancers physiology

Gastrointestinal cancers account for around 40% of cancer-related deaths worldwide, representing a global health burden. There is a growing body of evidence highlighting the link between microbiota and gastrointestinal tumorigenesis and/or resistance to therapy. In the present manuscript, we reviewed the published studies on the relationship between the microbiota and the different gastrointestinal tumors, namely, gastric, colorectal and esophageal, including also the cancer of accessory organs such as liver and pancreas. There is an emergent interest in the manipulation of gastrointestinal microflora in order to understand the gastrointestinal tumorigenesis' processes and the establishment of chemoresistance mechanisms.

Role of Gut Microbiota in Hepatocarcinogenesis

Hepatocellular carcinoma (HCC), one of the leading causes of death worldwide, has a causal nexus with liver injury, inflammation, and regeneration that accumulates over decades. Observations from recent studies have accounted for the involvement of the gut–liver axis in the pathophysiological mechanism responsible for HCC. The human intestine nurtures a diversified colony of microorganisms residing in the host ecosystem. The intestinal barrier is critical for conserving the normal physiology of the gut microbiome. Therefore, a rupture of this barrier or dysbiosis can cause the intestinal microbiome to serve as the main source of portal-vein endotoxins, such as lipopolysaccharide, in the progression of hepatic diseases. Indeed, increased bacterial translocation is a key sign of HCC. Considering the limited number of clinical studies on HCC with respect to the microbiome, we focus on clinical as well as animal studies involving the gut microbiota, with the current understandings of the mechanism by which the intestinal dysbiosis promotes hepatocarcinogenesis. Future research might offer mechanistic insights into the specific phyla targeting the leaky gut, as well as microbial dysbiosis, and their metabolites, which represent key pathways that drive HCC-promoting microbiome-mediated liver inflammation and fibrosis, thereby restoring the gut barrier function.

Gut microbiota in liver disease: too much is harmful, nothing at all is not helpful either

The intestinal microbiome plays a major role in the pathogenesis of liver disease, with a hallmark event being dysbiosis, or an imbalance of pathobionts and beneficial bacteria with the associated deleterious effects on their host. Reducing the number of intestinal bacteria with antibiotic treatment is generally advantageous in experimental liver diseases. Complete absence of intestinal microbiota as in germ-free rodents can be protective in autoimmune hepatitis and hepatic tumors induced by chemicals, or it can exacerbate disease as in acute toxic liver injury and liver fibrosis/cirrhosis. In alcoholic liver disease, nonalcoholic fatty liver disease, and autoimmune cholangiopathies, germ-free status can be associated with worsened or improved hepatic phenotype depending on the experimental model and type of rodent. Some of the unexpected outcomes can be explained by the limitations of rodents raised in a germ-free environment including a deficient immune system and an altered metabolism of lipids, cholesterol, xenobiotics/toxins, and bile acids. Given these limitations and to advance understanding of the interactions between host and intestinal microbiota, simplified model systems such as humanized gnotobiotic mice, or gnotobiotic mice monoassociated with a single bacterial strain or colonized with a defined set of microbes, are unique and useful models for investigation of liver disease in a complex ecosystem.

Integration of microbiology, molecular pathology, and epidemiology: a new paradigm to explore the pathogenesis of microbiome-driven neoplasms

Molecular pathological epidemiology (MPE) is an integrative transdisciplinary field that addresses heterogeneous effects of exogenous and endogenous factors (collectively termed 'exposures'), including microorganisms, on disease occurrence and consequences, utilising molecular pathological signatures of the disease. In parallel with the paradigm of precision medicine, findings from MPE research can provide aetiological insights into tailored strategies of disease prevention and treatment. Due to the availability of molecular pathological tests on tumours, the MPE approach has been utilised predominantly in research on cancers including breast, lung, prostate, and colorectal carcinomas. Mounting evidence indicates that the microbiome (inclusive of viruses, bacteria, fungi, and parasites) plays an important role in a variety of human diseases including neoplasms. An alteration of the microbiome may be not only a cause of neoplasia but also an informative biomarker that indicates or mediates the association of an epidemiological exposure with health conditions and outcomes. To adequately educate and train investigators in this emerging area, we herein propose the integration of microbiology into the MPE model (termed 'microbiology-MPE'), which could improve our understanding of the complex interactions of environment, tumour cells, the immune system, and microbes in the tumour microenvironment during the carcinogenic process. Using this approach, we can examine how lifestyle factors, dietary patterns, medications, environmental exposures, and germline genetics influence cancer development and progression through impacting the microbial communities in the human body. Further integration of other disciplines (e.g. pharmacology, immunology, nutrition) into microbiology-MPE would expand this developing research frontier. With the advent of high-throughput next-generation sequencing technologies, researchers now have increasing access to large-scale metagenomics as well as other omics data (e.g. genomics, epigenomics, proteomics, and metabolomics) in population-based research. The integrative field of microbiology-MPE will open new opportunities for personalised medicine and public health. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The role of gut microbiota in liver disease development and treatment

Liver cancer is the sixth most common cancer worldwide, and the third most common cause of cancer-related death. Hepatocellular carcinoma (HCC), which accounts for more than 90% of primary liver cancers, is an important public health problem. In addition to cirrhosis caused by hepatitis B viral (HBV) or hepatitis C viral (HCV) infection, non-alcoholic fatty liver disease (NAFLD) is becoming a major risk factor for liver cancer because of the prevalence of obesity. Non-alcoholic steatohepatitis (NASH) will likely become the leading indication for liver transplantation in the future. It is well recognized that gut microbiota is a key environmental factor in the pathogenesis of liver disease and cancer. The interplay between gut microbiota and liver disease has been investigated in animal and clinical studies. In this article, we summarize the roles of gut microbiota in the development of liver disease as well as gut microbiota-targeted therapies.

The Therapeutic Implications of the Gut Microbiome and Probiotics in Patients with NAFLD

Recent breakthrough in our understanding pertaining to the pathogenesis of nonalcoholic fatty liver disease (NAFLD) has pointed to dysregulation or derangement of the gut microbiome, also known as dysbiosis. This has led to growing interest in probiotic supplementation as a potential treatment method for NAFLD due to its ability to retard and/or reverse dysbiosis and restore normal gut flora. A thorough review of medical literature was completed from inception through July 10, 2018 on the PubMed database by searching for key terms such as NAFLD, probiotics, dysbiosis, synbiotics, and nonalcoholic steatohepatitis (NASH). All studies reviewed indicate that probiotics had a beneficial effect in patients with NAFLD and its subset NASH. Results varied between studies, but there was evidence demonstrating improvement in liver enzymes, hepatic inflammation, hepatic steatosis, and hepatic fibrosis. No major adverse effects were noted. Currently, there are no guidelines addressing the use of probiotics in the setting of NAFLD. In conclusion, probiotics appear to be a promising option in the treatment of NAFLD. Future research is necessary to assess the efficacy of probiotics in patients with NAFLD.

The Interplay between Immunity and Microbiota at Intestinal Immunological Niche: The Case of Cancer

The gut microbiota is central to the pathogenesis of several inflammatory and autoimmune diseases. While multiple mechanisms are involved, the immune system clearly plays a special role. Indeed, the breakdown of the physiological balance in gut microbial composition leads to dysbiosis, which is then able to enhance inflammation and to influence gene expression. At the same time, there is an intense cross-talk between the microbiota and the immunological niche in the intestinal mucosa. These interactions may pave the way to the development, growth and spreading of cancer, especially in the gastro-intestinal system. Here, we review the changes in microbiota composition, how they relate to the immunological imbalance, influencing the onset of different types of cancer and the impact of these mechanisms on the efficacy of traditional and upcoming cancer treatments.

Intestinally derived bacterial products stimulate development of nonalcoholic steatohepatitis

Fatty livers are susceptible to factors that cause inflammation and fibrosis, but fat deposition and the inflammatory response can be dissociated. While nonalcoholic fatty liver disease (NAFLD), caused by pathologic fat accumulation inside the liver, can remain stable for several years, in other cases NAFLD progresses to nonalcoholic steatohepatitis (NASH), which is characterized by fat accumulation and inflammation and is not a benign condition. In this review, we discuss the NASH host cells and microbial mechanisms that stimulate inflammation and predispose the liver to hepatocyte injury and fibrotic stages via increased lipid deposition. We highlight the interactions between intestine-derived bacterial products, such as lipopolysaccharide, and nutritional models of NAFLD and/or obese individuals. The results of modulating enteric microbiota suggest that gut-derived endotoxins may be essential determinants of fibrotic progression and regression in NASH.