Intestinal microbiota homeostasis analysis in riboflavin-treated alcoholic liver disease.

Alcoholic liver disease (ALD) is a disease with high incidence, limited therapies, and poor prognosis. The present study aims to investigate the effect of riboflavin on ALD and explore its potential therapeutic mechanisms. C57BL/6 mice were divided into the control, alcohol, and alcohol+ riboflavin groups. 16S rRNA-seq and RNA-seq analysis were utilized to analyze the polymorphism of intestinal microbiota and the transcriptome heterogeneity respectively. KEGG and GO enrichment analysis were performed. CIBERSORTx was applied to evaluate the immune cell infiltration level. Publicly available transcriptome data of ALD was enrolled and combined with the RNA-seq data to identify the immune subtypes of ALD. Pathological and histology analysis demonstrated that riboflavin reversed the progression of ALD. 16S rRNA-seq results showed that riboflavin could regulate alcohol-induced intestinal microbiota alteration. Intestinal microbiota polymorphism analysis indicated that VLIDP may contribute to the progression of ALD. Based on the VLIDP pathway, two subtypes were identified. Immune microenvironment analysis indicated that the upregulated inflammatory factors may be important regulators of ALD. In conclusion, intestinal microbiota homeostasis was associated with the protective effect of riboflavin against ALD, which was likely mediated by modulating inflammatory cell infiltration. Riboflavin emerges as a promising therapeutic candidate for the management of ALD.

Bacteroides acidifaciens drives a liver detox program.

Alcohol-associated liver disease is a leading cause of chronic liver conditions, yet there are limited effective therapies. In this issue of Cell Host & Microbe, Shen et al. demonstrate that soluble dietary fiber enhances intestinal Bacteroides acidifaciens, which ameliorates alcohol-associated liver injury in mice by activating hepatic ornithine aminotransferase.

A protective mechanism of heat inactivation to enhance Levilactobacillus brevis PDD-2 against alcohol-induced chronic liver disease based on proteomic analysis.

A proteomics-based analysis of the effect of heat inactivation on the alleviation of alcoholic liver disease (ALD) using Levilactobacillus brevis PDD-2 is presented, aimed at exploring the potential and mechanisms of postbiotic elements prepared through heat inactivation in the treatment of ALD. It was found that L. brevis PDD-2 and its postbiotic (heat-inactivated L. brevis PDD-2) alleviate chronic ALD via the gut-liver axis. In particular, heat-inactivated L. brevis PDD-2 significantly increased the relative abundance of Erysipelotrichaceae and better facilitated the oxidative stress balance in the liver. The tandem mass tag (TMT)-based quantitative proteomics technique analyses revealed that heat-inactivated L. brevis PDD-2 was associated with up-regulated expression levels of proteins related to the redox system, cellular metabolism, amino acid and oligopeptide transport, and surface proteins with immunomodulatory capacity. These findings provide a theoretical basis for developing novel therapeutic strategies and lay a solid foundation for further revealing its exhaustive mechanisms.

Dietary fiber alleviates alcoholic liver injury via Bacteroides acidifaciens and subsequent ammonia detoxification.

The gut microbiota and diet-induced changes in microbiome composition have been linked to various liver diseases, although the specific microbes and mechanisms remain understudied. Alcohol-related liver disease (ALD) is one such disease with limited therapeutic options due to its complex pathogenesis. We demonstrate that a diet rich in soluble dietary fiber increases the abundance of Bacteroides acidifaciens (B. acidifaciens) and alleviates alcohol-induced liver injury in mice. B. acidifaciens treatment alone ameliorates liver injury through a bile salt hydrolase that generates unconjugated bile acids to activate intestinal farnesoid X receptor (FXR) and its downstream target, fibroblast growth factor-15 (FGF15). FGF15 promotes hepatocyte expression of ornithine aminotransferase (OAT), which facilitates the metabolism of accumulated ornithine in the liver into glutamate, thereby providing sufficient glutamate for ammonia detoxification via the glutamine synthesis pathway. Collectively, these findings uncover a potential therapeutic strategy for ALD involving dietary fiber supplementation and B. acidifaciens.

Hepatoprotective potential of four fruit extracts rich in different structural flavonoids against alcohol-induced liver injury via gut microbiota-liver axis.

Alcoholic liver injury (ALI) accounts for a major share of the global burden of non-viral liver disease. In the absence of specialized medications, research on using fruit flavonoids as a treatment is gaining momentum. This study investigated the hepatoprotective effects of four fruits rich in structurally diverse flavonoids: ougan (Citrus reticulata cv. Suavissima, OG), mulberry (Morus alba L., MB), apple (Malus × domestica Borkh., AP), and turnjujube (Hovenia dulcis Thunnb., TJ). A total of one flavanone glycoside, three polymethoxyflavones, two anthocyanins, one flavonol glycoside, and one dihydroflavonol were identified through UPLC analysis. In an acute ethanol-induced ALI mouse model, C57BL/6J mice were supplemented with 200 mg/kg·BW/day of different fruit extracts for three weeks. Our results showed that the four extracts exhibited promising benefits in improving lipid metabolism disorders, iron overload, and oxidative stress. RT-PCR and Western blot tests suggested that the potential mechanism may partially be attributed to the activation of the NRF2-mediated antioxidant response and the inhibition of ferroptosis pathways. Furthermore, fruit extracts administration demonstrated a specific regulatory role in intestinal microecology, with increases in beneficial bacteria such as Dubosiella, Lactobacillus, and Bifidobacterium. Spearman correlation analysis revealed strong links between intestinal flora, lipid metabolism, and iron homeostasis, implying that the fruit extracts mitigated ALI via the gut microbiota-liver axis. In vitro experiments reaffirmed the activity against ethanol-induced oxidative damage and highlighted the positive effects of flavonoid components. These findings endorse the prospective application of OG, MB, AP, and TJ as dietary supplements or novel treatments for ALI.

Gut microbiota-based machine-learning signature for the diagnosis of alcohol-associated and metabolic dysfunction-associated steatotic liver disease.

Alcoholic-associated liver disease (ALD) and metabolic dysfunction-associated steatotic liver disease (MASLD) show a high prevalence rate worldwide. As gut microbiota represents current state of ALD and MASLD via gut-liver axis, typical characteristics of gut microbiota can be used as a potential diagnostic marker in ALD and MASLD. Machine learning (ML) algorithms improve diagnostic performance in various diseases. Using gut microbiota-based ML algorithms, we evaluated the diagnostic index for ALD and MASLD. Fecal 16S rRNA sequencing data of 263 ALD (control, elevated liver enzyme [ELE], cirrhosis, and hepatocellular carcinoma [HCC]) and 201 MASLD (control and ELE) subjects were collected. For external validation, 126 ALD and 84 MASLD subjects were recruited. Four supervised ML algorithms (support vector machine, random forest, multilevel perceptron, and convolutional neural network) were used for classification with 20, 40, 60, and 80 features, in which three nonsupervised ML algorithms (independent component analysis, principal component analysis, linear discriminant analysis, and random projection) were used for feature reduction. A total of 52 combinations of ML algorithms for each pair of subgroups were performed with 60 hyperparameter variations and Stratified ShuffleSplit tenfold cross validation. The ML models of the convolutional neural network combined with principal component analysis achieved areas under the receiver operating characteristic curve (AUCs) > 0.90. In ALD, the diagnostic AUC values of the ML strategy (vs. control) were 0.94, 0.97, and 0.96 for ELE, cirrhosis, and liver cancer, respectively. The AUC value (vs. control) for MASLD (ELE) was 0.93. In the external validation, the AUC values of ALD and MASLD (vs control) were > 0.90 and 0.88, respectively. The gut microbiota-based ML strategy can be used for the diagnosis of ALD and MASLD.ClinicalTrials.gov NCT04339725.

Apolipoprotein H deficiency exacerbates alcohol-induced liver injury via gut Dysbiosis and altered bile acid metabolism.

BACKGROUND: APOH plays an essential role in lipid metabolism and the transport of lipids in the circulation. Previous studies have shown that APOH deficiency causes fatty liver and gut microbiota dysbiosis in mouse models. However, the role and potential mechanisms of APOH deficiency in the pathogenesis of alcoholic liver disease remain unclear. METHODS: C57BL/6 WT and ApoH-/- mice were used to construct the binge-on-chronic alcohol feeding model. Mouse liver transcriptome, targeted bile acid metabolome, and 16S gut bacterial taxa were assayed and analyzed. Open-source human liver transcriptome dataset was analyzed. RESULTS: ApoH-/- mice fed with alcohol showed severe hepatic steatosis. Liver RNAseq and RT-qPCR data indicated that APOH deficiency predominantly impacts hepatic lipid metabolism by disrupting de novo lipogenesis, cholesterol processing, and bile acid metabolism. A targeted bile acid metabolomics assay indicated significant changes in bile acid composition, including increased percentages of TCA in the liver and DCA in the gut of alcohol-fed ApoH-/- mice. The concentrations of CA, NorCA, and HCA in the liver were higher in ApoH-/- mice on an ethanol diet compared to the control mice (p < 0.05). Additionally, APOH deficiency altered the composition of gut flora, which correlated with changes in the liver bile acid composition in the ethanol-feeding mouse model. Finally, open-source transcript-level data from human ALD livers highlighted a remarkable link between APOH downregulation and steatohepatitis, as well as bile acid metabolism. CONCLUSION: APOH deficiency aggravates alcohol induced hepatic steatosis through the disruption of gut microbiota homeostasis and bile acid metabolism in mice.

Differences in the Ability of Lactic Acid Bacteria To Prevent Acute Alcohol-Induced Liver Injury via the Gut Microbiota-Bile Acid-Liver Axis.

Probiotics can regulate gut microbiota and protect against acute alcohol-induced liver injury through the gut-liver axis. However, efficacy is strain-dependent, and their mechanism remains unclear. This study investigated the effect of lactic acid bacteria (LAB), including Lacticaseibacillus paracasei E10 (E10), Lactiplantibacillus plantarum M (M), Lacticaseibacillus rhamnosus LGG (LGG), Lacticaseibacillus paracasei JN-1 (JN-1), and Lacticaseibacillus paracasei JN-8 (JN-8), on the prevention of acute alcoholic liver injury in mice. We found that LAB pretreatment reduced serum alanine transaminase (ALT) and aspartate transaminase (AST) and reduced hepatic total cholesterol (TC) and triglyceride (TG). JN-8 pretreatment exhibited superior efficacy in improving hepatic antioxidation. LGG and JN-8 pretreatment significantly attenuated hepatic and colonic inflammation by decreasing the expression of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) and increasing the expression of interleukin 10 (IL-10). JN-1 and JN-8 pretreatments have better preventive effects than other LAB pretreatment on intestinal barrier dysfunction. In addition, the LAB pretreatment improved gut microbial dysbiosis and bile acid (BA) metabolic abnormality. All of the strains were confirmed to have bile salt deconjugation capacities in vitro, where M and JN-8 displayed higher activities. This study provides new insights into the prevention and mechanism of LAB strains in preventing acute alcoholic liver injury.

MUP1 mediates urolithin A alleviation of chronic alcohol-related liver disease via gut-microbiota-liver axis.

Alcohol-related liver disease (ALD) is recognized as a global health crisis, contributing to approximately 20% of liver cancer-associated fatalities. Dysbiosis of the gut microbiome is associated with the development of ALD, with the gut microbial metabolite urolithin A (UA) exhibiting a potential for alleviating liver symptoms. However, the protective efficacy of UA against ALD and its underlying mechanism mediated by microbiota remain elusive. In this study, we provide evidence demonstrating that UA effectively ameliorates alcohol-induced metabolic disorders and hepatic endoplasmic reticulum (ER) stress through a specific gut-microbiota-liver axis mediated by major urinary protein 1 (MUP1). Moreover, UA exhibited the potential to restore alcohol-induced dysbiosis of the intestinal microbiota by enriching the abundance of Bacteroides sartorii (B. sartorii), Parabacteroides distasonis (P. distasonis), and Akkermansia muciniphila (A. muciniphila), along with their derived metabolite propionic acid. Partial attenuation of the hepatoprotective effects exerted by UA was observed upon depletion of gut microbiota using antibiotics. Subsequently, a fecal microbiota transplantation (FMT) experiment was conducted to evaluate the microbiota-dependent effects of UA in ALD. FMT derived from mice treated with UA exhibited comparable efficacy to direct UA treatment, as it effectively attenuated ER stress through modulation of MUP1. It was noteworthy that strong associations were observed among the hepatic MUP1, gut microbiome, and metabolome profiles affected by UA. Intriguingly, oral administration of UA-enriched B. sartorii, P. distasonis, and A. muciniphila can enhance propionic acid production to effectively suppress ER stress via MUP1, mimicking UA treatment. Collectively, these findings elucidate the causal mechanism that UA alleviated ALD through the gut-microbiota-liver axis. This unique mechanism sheds light on developing novel microbiome-targeted therapeutic strategies against ALD.

Nutritional and microbiota-based therapeutic interventions for alcohol-associated liver disease: From pathogenesis to therapeutic insights.

Alcohol-associated liver disease (ALD) manifests as a consequence of prolonged and excessive alcohol consumption. This disease is closely associated with the interplay between gut health and liver function, which can lead to complex pathophysiological changes in the body. This review offers a comprehensive exploration of ALD's multifaceted nature, with a keen focus on its pathogenesis and the potential of nutritional and microbiota-based therapies. Insights derived from diverse case studies are utilized to shed light on how interventions can rebalance the gut microbiome and enhance liver function in ALD patients. Furthermore, the feasibility of liver transplantation and stem cell therapy as ultimate measures for ALD has been discussed, with acknowledgment of the inherent risks and challenges accompanying them. ALD's complexity underscores the necessity for a thorough understanding of its etiology and progression to devise effective treatments that mitigate its profound impact on an individual's health.

COMPARISON OF GUT MICROBIOTA IN ALCOHOLIC AND METABOLIC-DYSFUNCION ASSOCIATED STEATOTIC LIVER DISEASE IN ANIMAL MODELS.

BACKGROUND: Alcoholic liver disease (ALD) and metabolic-dysfunction associated steatotic liver disease (MASLD) are common, and gut microbiota (GM) is involved with both. Here we compared GM composition in animal models of MASLD and ALD to assess whether there are specific patterns for each disease. METHODS: MASLD model- adult male Sprague Dawley rats, randomized into two groups: MASLD-control (n=10) fed a standard diet; MASLD-group (n=10) fed a high-fat-choline-deficient diet for 16 weeks. ALD model- adult male Wistar rats randomized: ALD-control (n=8) fed a standard diet and water+0.05% saccharin, ALD groups fed with sunflower seed and 10% ethanol+0.05% saccharin for 4 or 8 weeks (ALC4, n=8; ALC8, n=8). ALC4/8 on the last day received alcoholic binge (5g/kg of ethanol). Afterwards, animals were euthanized, and feces were collected for GM analysis. RESULTS: Both experimental models induced typical histopathological features of the diseases. Alpha diversity was lower in MASLD compared with ALD (p<0.001), and structural pattern was different between them (P<0.001). Bacteroidetes (55.7%), Firmicutes (40.6%), and Proteobacteria (1.4%) were the most prevalent phyla in all samples, although differentially abundant among groups. ALC8 had a greater abundance of the phyla Cyanobacteria (5.3%) and Verrucomicrobiota (3.2%) in relation to the others. Differential abundance analysis identified Lactobacillaceae_unclassified, Lachnospiraceae_NK4A136_group, and Turicibacter associated with ALC4 and the Clostridia_UCG_014_ge and Gastranaerophilales_ge genera to ALC8. CONCLUSION: In this study, we demonstrated that the structural pattern of the GM differs significantly between MASLD and ALD models. Studies are needed to characterize the microbiota and metabolome in both clinical conditions to find new therapeutic strategies. BACKGROUND: •Changes in the composition of the intestinal microbiota are related to the development of alcoholic liver disease and metabolic-dysfunction associated steatotic liver disease. BACKGROUND: •The diversity of the intestinal microbiota was lower in animals with MASLD compared to ALD. BACKGROUND: •The structural pattern of the intestinal microbiota was significantly different among the experimental groups. BACKGROUND: •Studies are needed to characterize the composition of the intestinal microbiota and metabolome to find new therapeutic strategies.

Fibroblast Growth Factor 19 Alters Bile Acids to Induce Dysbiosis in Mice With Alcohol-Induced Liver Disease.

BACKGROUND & AIMS: Excessive alcohol consumption can lead to alcohol-associated liver disease, a spectrum of conditions ranging from steatosis to fibrosis and cirrhosis. Bile acids regulate metabolic pathways by binding to cellular and nuclear receptors, and they also interact with the gut microbiome to control microbial overgrowth. Fibroblast growth factor 19 (FGF-19) is an ileum-derived hormone induced and released in response to bile acid activation of the nuclear receptor farnesoid X receptor. FGF-19 signaling is dysregulated with ethanol consumption and is increased in patients with alcoholic hepatitis. Here, we examined the effects of FGF-19 in a mouse model of chronic + binge ethanol feeding. METHODS: After injection of adeno-associated virus-green fluorescent protein or AAV-FGF-19, female C57BL/6J mice were pair-fed a Lieber DeCarli liquid diet (5% v/v) or control diet for 10 days and were given a bolus gavage of 5% ethanol or maltose control to represent a binge drinking episode. Tissues were collected for analysis 9 hours after the binge. RESULTS: Chronic + binge ethanol feeding induced steatosis regardless of FGF-19 expression. Interestingly, FGF-19 and ethanol resulted in significantly increased liver inflammation, as measured by Il6, Tgfß, and Tnfα, compared with ethanol alone. Both ethanol and FGF-19 decreased bile acid synthesis, and FGF-19 significantly reduced secondary bile acids, leading to overgrowth of specific pathogenic bacteria including Enterococcus faecalis, Escherichia coli, and Clostridium perfringens. CONCLUSIONS: Dysregulation of FGF-19 and consequent changes in bile acid synthesis and composition during alcohol consumption may be a contributing factor to alcohol-induced liver disease and dysbiosis.

Bifidobacterium longum subsp. longum BL21 ameliorates alcoholic liver disease in mice through enhancement of the hepatic antioxidant capacity and modulation of the gut microbiota.

BACKGROUND: Alcoholic liver disease (ALD) is a chronic liver injury caused by excessive alcohol consumption, could be impacted by gut-liver axis dysfunction. The gut microbiota plays a crucial role in the development and progression of ALD. Given the role of gut-liver axis dysfunction in ALD, strategies targeting gut microbiota modulation have gained interest for therapeutic interventions. Bifidobacterium longum subsp. longum BL21 has shown promise in alleviating gut microbiota disturbances and metabolic regulation in high-fat diet-induced obesity and type 2 diabetes mellitus models. Thus, this study aimed to evaluate the therapeutic effect of BL21 on ALD mice and explore the potential mechanism by which the gut microbiota mediates the amelioration of ALD by BL21. METHODS: A total of 30 mice were randomly assigned to three groups (n = 10 mice/group): a healthy control (CTL) group, an ALD group, and a BL21 group. Each group was fed a Lieber-DeCarli liquid diet with (ALD and BL21) or without alcohol (CTL). The intervention period lasted 6 weeks, after which the effects of BL21 intervention (intragastric administration of 1 billion CFU of BL21 daily) on serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, hepatic oxidative stress, serum inflammatory cytokine levels, and gut microbiota composition in ALD mice were investigated. RESULTS: Dietary BL21 reduced the ethanol-induced abnormal elevation of serum AST and ALT levels in ALD mice (P < 0.001 for both). BL21 treatment significantly attenuated alcohol-induced hepatic oxidative stress by decreasing malondialdehyde concentration and increasing superoxide dismutase, catalase, and glutathione concentrations in the livers of ALD mice. In addition, the serum levels of tumor necrosis factor-alpha, interleukin-1 beta (IL-1ß), and IL-6 were significantly lower (P < 0.001 for both), while that of IL-10 was significantly higher (P < 0.05), in the BL21 group than in the ALD group. Intestinal microbiota analysis showed an increased relative abundance of Escherichia/Shigella, Enterococcus, and Alistipes in the ALD group compared with the CTL group. BL21 intervention increased the relative abundance of Bifidobacterium and Akkermansia compared with the ALD group. CONCLUSION: Dietary BL21 ameliorates ALD via enhancement of the hepatic antioxidant capacity and modulation of the gut microbiota and may therefore be a promising strategy to prevent or treat ALD.

Protective Effect of Ganoderma lucidum Spore Powder on Acute Liver Injury in Mice and its Regulation of Gut Microbiota.

BACKGROUND: Ganoderma lucidum spore powder (GLSP) has abundant pharmacological activities. However, the difference in the hepatoprotective function of sporoderm-broken and sporoderm-unbroken Ganoderma spore powder has not been studied. This study is the first to investigate the effects of both sporoderm-damaged and sporoderm-intact GLSP on the improvement of acute alcoholic liver injury in mice and gut microbiota of mice. METHODS: Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and interleukin 1ß (IL-1ß), interleukin 18 (IL-18), and tumor necrosis factor-α (TNF-α) levels in liver tissues from mice in each group were detected by enzyme-linked immunosorbent assay (ELISA) kits, and histological analysis of liver tissue sections was performed to evaluate the liver-protecting effects of both sporoderm-broken and sporoderm-unbroken GLSP. Additionally, 16S rDNA sequencing of feces from the bowels of mice was performed to compare the regulatory effects of both sporoderm-broken and sporoderm-unbroken GLSP on the gut microbiota of mice. RESULTS: Compared with those in the 50% ethanol model group (MG), sporoderm-broken GLSP significantly reduced serum AST and ALT levels (p < 0.0001) and the release of the inflammatory factors, including IL-1ß, IL-18, and TNF-α (p < 0.0001), and effectively improved the pathological state of liver cells; sporoderm-unbroken GLSP significantly reduced the ALT content (p = 0.0002) and the release of the inflammatory factors, including IL-1ß (p < 0.0001), IL-18 (p = 0.0018), and TNF-α (p = 0.0005), and reduced the serum AST content, but the reduction was not significant; compared with the gut microbiota of the MG, sporoderm-broken GLSP reduced the levels of Verrucomicrobia and Escherichia_Shigella, increased the relative abundance of beneficial bacteria such as Bacteroidetes, and decreased the abundance levels of harmful bacteria, such as Proteobacteria and Candidatus_Saccharibacteria; sporoderm-unbroken GLSP could reduce the abundance levels of harmful bacteria, such as Verrucomicrobia and Candidatus_Saccharibacteria; and GLSP treatment alleviates the downregulation of the levels of translation, ribosome structure and biogenesis, and lipid transport and metabolism in liver-injured mice; Conclusions: GLSP can alleviate the imbalance of gut microbiota and improve liver injury, and the effect of sporoderm-broken GLSP is better.

Microbiome Alterations in Alcohol Use Disorder and Alcoholic Liver Disease.

Microbiome alterations are emerging as one of the most important factors that influence the course of alcohol use disorder (AUD). Recent advances in bioinformatics enable more robust and accurate characterization of changes in the composition of the microbiome. In this study, our objective was to provide the most comprehensive and up-to-date evaluation of microbiome alterations associated with AUD and alcoholic liver disease (ALD). To achieve it, we have applied consistent, state of art bioinformatic workflow to raw reads from multiple 16S rRNA sequencing datasets. The study population consisted of 122 patients with AUD, 75 with ALD, 54 with non-alcoholic liver diseases, and 260 healthy controls. We have found several microbiome alterations that were consistent across multiple datasets. The most consistent changes included a significantly lower abundance of multiple butyrate-producing families, including Ruminococcaceae, Lachnospiraceae, and Oscillospiraceae in AUD compared to HC and further reduction of these families in ALD compared with AUD. Other important results include an increase in endotoxin-producing Proteobacteria in AUD, with the ALD group having the largest increase. All of these alterations can potentially contribute to increased intestinal permeability and inflammation associated with AUD and ALD.

Malassezia restricta promotes alcohol-induced liver injury.

Chronic alcohol consumption is associated with intestinal fungal dysbiosis, yet we understand little about how alterations of intestinal fungi (mycobiota) contribute to the pathogenesis of alcohol-associated liver disease. By reanalyzing internal transcribed spacer 2 amplicon sequencing of fecal samples from a cohort of 66 patients with alcohol use disorder for presence (as opposed to relative abundance) of fungal species, we observed that the presence of Malassezia restricta was associated with increased markers of liver injury. M. restricta exacerbates ethanol-induced liver injury both in acute binge and chronic ethanol-feeding models in mice. Using bone marrow chimeric mice, we found that the disease exacerbating effect by M. restricta was mediated by C-type lectin domain family 4, member N on bone marrow-derived cells. M. restricta induces inflammatory cytokines and chemokines in Kupffer cells through C-type lectin domain family 4, member N signaling. Targeting fungal pathobionts might be a therapeutic strategy for alcohol-associated liver disease.

Alcoholic liver disease and intestinal microbiota in an experimental model: Biochemical, inflammatory, and histologic parameters.

OBJECTIVES: Alcoholic liver disease (ALD) is the leading cause of alcohol-related deaths worldwide. Experimental ALD models are expensive and difficult to reproduce. A low-cost, reproducible ALD model was developed, and liver damage compared with the gut microbiota. The aims of this study were to develop an experimental model of ALD, through a high-fat diet, the chronic use of ethanol, and intragastric alcohol binge; and to evaluate the composition of the gut microbiota and its correlation with markers of inflammatory and liver disease progression in this model. METHODS: Adult male Wistar rats were randomized (N = 24) to one of three groups: control (standard diet and water + 0.05% saccharin), ALC4 and ALC8 (sunflower seed, 10% ethanol + 0.05% saccharin for 4 and 8 wk, respectively). On the last day, ALC4/8 received alcoholic binge (5 g/kg). Clinical, nutritional, biochemical, inflammatory, pathologic, and gut microbiota data were analyzed. RESULTS: ALC4/8 animals consumed more alcohol and lipids (P < 0.01) and less total energy, liquids, solids, carbohydrates, and proteins (P < 0.01), and gained less weight (P < 0.01) than controls. ALC8 had lower Lee index scores than controls and ALC4 (P < 0.01). Aminotransferases increased and albumin diminished in ALC4/8 but not in the control group (P < 0.03 for all). Glucose and aspartate transaminase/alanine aminotransaminase ratios were higher in the ALC8 rats than in the controls (P < 0.03). Cholesterol was higher in ALC4 and lower in ALC8 compared with controls (P < 0.03). Albumin and high-density lipoprotein cholesterol levels were lower in ALC8 (P < 0.03). Hepatic concentration of triacylglycerols was higher in ALC8 than in ALC4 and controls (P < 0.05). ALC4/8 presented microvesicular grade 2 and 3 steatosis, respectively, and macrovesicular grade 1. No change in the gene expression of inflammatory markers between groups was seen. ALC4/8 had lower fecal bacterial α-diversity and relative abundance of Firmicutes (P < 0.005) and greater Bacterioidetes (P < 0.0007) and Protobacteria (P < 0.001) than controls. Gut microbiota correlated with serum and liver lipids, steatosis, albumin, and aminotransferases (P < 0.01 for all). CONCLUSION: The model induced nutritional, biochemical, histologic, and gut microbiota changes, and appears to be useful in the study of therapeutic targets.

Emerging Role of Edible Exosomes-Like Nanoparticles (ELNs) as Hepatoprotective Agents.

Liver diseases are responsible for over 2 million deaths each year and the number is rapidly increasing. There is a strong link between edibles, gut microbiota, liver fat and the liver damage. There are very limited therapeutic options for treatment specifically for Alcoholic liver disease (ALD) and Non-Alcoholic liver disease (NAFLD). Recently, identified Edible Exosomes-like nanoparticles (ELNs) are plant derived membrane bound particles, released by microvesicular bodies for cellular communication and regulate immune responses against many pathogens. Many studies have identified their role as hepatoprotective agent as they carry bioactive material as cargoes which are transferred to recipient cells and affect various biological functions in liver. They are also known to carry specific miRNA, which increases the copy number of beneficial bacteria and the production of lactic acid metabolites in gut and hence restrains from liver injury through portal vein. Few in-vitro studies also have been reported about the anti-inflammatory, anti-oxidant and detoxification properties of ELNs which again protects the liver. The properties such as small size, biocompatibility, stability, low toxicity and non-immunogenicity make ELNs as a better therapeutic option. But, till now, studies on the effect of ELNs as therapeutics are still at its infancy yet promising. Here we discuss about the isolation, characterization, their role in maintaining the gut microbiome and liver homeostasis. Also, we give an outline about the latest advances in ELNs modifications, its biological effects, limitations and we propose the future prospective of ELNs as therapeutics.

NLRP6 Inflammasome Modulates Disease Progression in a Chronic-Plus-Binge Mouse Model of Alcoholic Liver Disease.

A considerable percentage of the population is affected by alcoholic liver disease (ALD). It is characterized by inflammatory signals from the liver and other organs, such as the intestine. The NLR family pyrin domain containing 6 (NLRP6) inflammasome complex is one of the most important inflammatory mediators. The aim of this study was to evaluate a novel mouse model for ALD characterized by 8-week chronic-plus-binge ethanol administration and to investigate the role of NLRP6 inflammasome for intestinal homeostasis and ALD progression using Nlrp6-/- mice. We showed that chronic-plus-binge ethanol administration triggers hepatic steatosis, injury, and neutrophil infiltration. Furthermore, we discovered significant changes of intestinal microbial communities, including increased relative abundances of bacteria within the phyla Bacteroidota and Campilobacterota, as well as reduced Firmicutes. In this ALD model, inhibiting NLRP6 signaling had no effect on liver steatosis or damage, but had a minor impact on intestinal homeostasis via affecting intestinal epithelium function and gut microbiota. Surprisingly, Nlrp6 loss resulted in significantly decreased hepatic immune cell infiltration. As a result, our novel mouse model encompasses several aspects of human ALD, such as intestinal dysbiosis. Interfering with NLRP6 inflammasome activity reduced hepatic immune cell recruitment, indicating a disease-aggravating role of NLRP6 during ALD.