Gut microbiota mediates diurnal variation of acetaminophen induced acute liver injury in mice

Longitudinal Pharmacometabonomics for Predicting Malignant Tumor Patient Responses to Anlotinib Therapy: Phenotype, Efficacy, and Toxicity

Anlotinib is an oral small molecule inhibitor of multiple receptor tyrosine kinases (RTKs), which was approved by the National Medical Products Administration (NMPA) of China in 2018 for the third-line treatment of non-small cell lung cancer (NSCLC). Here, for the first time, the longitudinal pharmacometabonomics was explored for predicting malignant tumor patient responses to anlotinib, including the metabolic phenotype variation, drug efficacy, and toxicity. A total of 393 plasma samples from 16 subjects collected from a phase I additional study of anlotinib (NCT02752516) were submitted to targeted metabolomics analysis. The orthogonal partial least-squares discriminant analysis (OPLS-DA) models were constructed for the predication of anlotinib efficacy and toxicity based on the longitudinal pharmacometabonomics data. Statistical results showed that 38 metabolites, mainly involved in aminoacyl-tRNA biosynthesis, alanine, aspartate, and glutamate metabolism, and steroid hormone biosynthesis, were all significantly upregulated attributing to anlotinib treatment. The anti-tumor efficacy and occurrence of proteinuria after anlotinib administration can be predicted with 100% accuracy using the established OPLS-DA models. Glycodeoxycholic acid and glycocholic acid possessed the most excellent sensitivity and specificity in predicting the efficacy of anlotinib, with area under the receiver operating characteristic curve (AUC of ROC curve) 0.847 and 0.828, respectively. NG, NG-dimethylarginine was the most promising biomarker for the prediction of proteinuria occurrence after anlotinib administration, with AUC of ROC curve 0.814. In conclusion, this work developed efficient and convenient discriminant models that can accurately predict the efficacy and toxicity of anlotinib based on longitudinal pharmacometabonomics study.

Isatidis Folium alleviates acetaminophen-induced liver injury in mice by enhancing the endogenous antioxidant system

Isatidis Folium (IF) has been clinically combined with acetaminophen (APAP), but the rationality of combinational therapy is still ambiguous. In the present study, the protective effect and related mechanism of IF on APAP-induced hepatotoxicity were evaluated. Hepatic histopathology and blood biochemistry investigations clearly demonstrated that IF could restore APAP-induced hepatotoxicity. Liver distribution study indicated that the hepatoprotective effect of IF on APAP is attributed to the reduction of N-acetyl-p-benzoquinone imine (NAPQI) in liver, which is a known hepatotoxic metabolite of APAP. Further study suggested the reduction is not via decreasing the generation of NAPQI through inhibiting the enzyme activities of CYP 1A2, 2E1, and 3A4 but via accelerating the transformation of NAPQI to NAPQI-GSH by promoting GSH and decreasing GSSG contents in liver. Furthermore, IF significantly enhanced the hepatic activities of GSH-associated enzymes in APAP-treated mice. In summary, IF could alleviate APAP-induced hepatotoxicity by reducing the content of NAPQI via enhancing the level of GSH and the followed generation of NAPQI-GSH which might be ascribed to the upregulation of GSH-associated enzymes.

Alterations of the Gut Microbiome Composition and Lipid Metabolic Profile in Radiation Enteritis

Radiation enteritis (RE) is a common complication in cancer patients receiving radiotherapy. Although studies have shown the changes of this disease at clinical, pathological and other levels, the dynamic characteristics of local microbiome and metabolomics are hitherto unknown. We aimed to examine the multi-omics features of the gut microecosystem, determining the functional correlation between microbiome and lipid metabolites during RE activity. By delivering single high-dose irradiation, a RE mouse model was established. High-throughput 16S rDNA sequencing and global lipidomics analysis were performed to examine microbial and lipidomic profile changes in the gut microecosystem. Spearman correlation analysis was used to determine the functional correlation between bacteria and metabolites. Clinical samples were collected to validate the above observations. During RE activity, the intestinal inflammation of the mice was confirmed by typical signs, symptoms, imaging findings and pathological evidences. 16S datasets revealed that localized irradiation dramatically altered the gut microbial composition, resulting in a decrease ratio of Bacteroidetes to Firmicutes. Lipidomics analysis indicated the remarkable lipidomic profile changes in enteric epithelial barrier, determining that glycerophospholipids metabolism was correlated to RE progression with the highest relevance. Spearman correlation analysis identified that five bacteria-metabolite pairs showed the most significant functional correlation in RE, including Alistipes-PC(36:0e), Bacteroides-DG(18:0/20:4), Dubosiella-PC(35:2), Eggerthellaceae-PC(35:6), and Escherichia-Shigella-TG(18:2/18:2/20:4). These observations were partly confirmed in human specimens. Our study provided a comprehensive description of microbiota dysbiosis and lipid metabolic disorders in RE, suggesting strategies to change local microecosystem to relieve radiation injury and maintain homeostasis.

The role of gut microbiome in chemical-induced metabolic and toxicological murine disease models

The role of gut microbiome in human health and disease is well established. While evidence-based pharmacological studies utilize a variety of chemical-induced metabolic and toxicological disease models that in part recapitulate the natural mode of disease pathogenesis, the mode of actions of these disease models are likely underexplored. Conventionally, the mechanistic principles of these disease models are established as direct tissue toxicity through redox imbalance and pro-inflammatory injury. However, emerging evidences suggest that the mode of action of these chemicals could be largely associated with changes in gut microbial populations, diversity and metabolic functions, affecting pathological changes along the gut-liver and gut-pancreas axis. Especially in these disease models, reversal of disease severity or less sensitivity to induced disease pathogenesis has been observed when germ-free or antibiotic-supplemented microbiota-depleted rodents were treated with disease causing chemicals. Thus, by summarizing evidences from in vivo pharmacological interventions, this review revisits the mode of action of carbon tetrachloride-induced cirrhosis, diethylnitrosamine-induced hepatocellular carcinoma, acetaminophen-induced hepatotoxicity and alloxan- and streptozotocin-induced diabetes through the light of gut microbiota. How changes in gut microbiome affects tissue-level toxicity likely through intestinal-level mechanisms like gastrointestinal inflammation and gut barrier dysfunction has also been discussed. Additionally, this review discusses potential pitfalls of inconsistent experimental models that precludes defining the gut microbial effects in evidence-based pharmacology. Collectively, this review emphasizes the underexplored role of microbial intervention in experimental pharmacology and aims to provide direction towards redefining and establishing microbiome-centric alternative mode of action of chemical-induced metabolic and toxicological disease models in pharmacological research.

Anti-inflammatory and antioxidant effects of Apium graveolens L. extracts mitigate against fatal acetaminophen-induced acute liver toxicity

In the present work, antioxidant activity, total phenolics (TP), and total flavonoids (TF) contents of aqueous and methanol extracts of celery were determined, in addition to untargeted metabolites profiling its methanol celery root extract (MCRE) via UPLC-MS. Although MCRE exhibited the lowest TPC and TFC levels, it presented the most potential hydroxyl radical quenching effect using electron paramagnetic resonance spin trapping technique. Treatment of Acetaminophen-induced hepatotoxicity (AAH) rats with MCRE lowered serum levels of AST, ALT, ALP, TNF-α, and IL-1β significantly. Additionally, MCRE significantly increased total antioxidant capacity (TAC) and glutathione (GSH) levels relative to AAH rats. Strikingly, Kaplan-Meier survival analysis of all groups revealed a 100% prevention of acetaminophen-induced mortality of rats by MCRE pretreatment (100 mg/kg/day). MCRE prevented AAH-associated severe weight loss and elicited normal behavior in the rescued rats. Our results suggest that pretreatment with MCRE can mitigate against overdosed acetaminophen-induced acute liver failure and warrant further investigations on the potential of postinjury intervention. PRACTICAL APPLICATIONS: Acetaminophen-induced hepatotoxicity (AAH) accounts for alerting numbers of overdose-related acute liver failure and liver transplant cases with increased morbidity and mortality rates. Currently proposed mechanisms implicate mitochondria-mediated oxidative stress and inflammation in the pathogenesis of AAH, which underline current interventions employing antioxidants to combat liver damage by over-dosed acetaminophen. The present work uncovers potent protective effects of some celery extracts (and their fractions) against acetaminophen-induced oxidative stress and inflammation. Treatment of rats with fatal liver injury with methanol extract of celery root significantly reduced secretion of liver enzymes and markedly decreased inflammatory as well as oxidative stress markers in these animals. This, in turn, rescued challenged rats exposed to fatal doses of acetaminophen completely, which establishes methanol extracts of celery roots as effective therapeutic intervention against AAH. The antioxidant capacity of the extracts was determined using EPR technique, and the secondary metabolites related to antioxidant activity were characterized via UPLC-MS.

Targeting gut microbiota for precision medicine: Focusing on the efficacy and toxicity of drugs

Intra- and interindividual variation in drug responses is one major reason for the failure of drug therapy, drug toxicity, and even the death of patients. Precision medicine, or personalized medicine, is a field of medicine that customizes an individual's medical diagnosis and treatment based on his/her genes, microbiomes, environments, etc. Over the past decade, a large number of studies have demonstrated that gut microbiota can modify the efficacy and toxicity of drugs, and the extent of the modification varies greatly from person to person because of the variability of the gut microbiota. Personalized manipulation of gut microbiota is an important approach to rectify the abnormal drug response. In this review, we aim to improve drug efficacy and reduce drug toxicity by combining precision medicine and gut microbiota. After describing the interactions between gut microbiota and xenobiotics, we discuss (1) the effects of gut microbiota on drug efficacy and toxicity and the corresponding mechanisms, (2) the variability of gut microbiota, which leads to variation in drug responses, (3) the biomarkers used for the patient stratification and treatment decisions before the use of drugs, and (4) the methods used for the personalized manipulation of gut microbiota to improve drug outcomes. Overall, we hope to improve the drug response by incorporating the knowledge of gut microbiota into clinical practice.

Aryl Hydrocarbon Receptor Activity in Hepatocytes Sensitizes to Hyperacute Acetaminophen-Induced Hepatotoxicity in Mice

BACKGROUND & AIMS

Acetaminophen (APAP)-induced liver injury is one of the most common causes of acute liver failure, however, a clear definition of sensitizing risk factors is lacking. Here, we investigated the role of the ligand-activated transcription factor aryl hydrocarbon receptor (Ahr) in APAP-induced liver injury. We hypothesized that Ahr, which integrates environmental, dietary, microbial and metabolic signals into complex cellular transcriptional programs, might act as a rheostat for APAP-toxicity.

METHODS

Wildtype or conditional Ahr knockout mice lacking Ahr in hepatocytes (Alb^Δ/ΔAhr) or myeloid cells (LysM^Δ/ΔAhr) were treated with the specific Ahr ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) together with APAP.

RESULTS

Ahr activation by ITE, which by itself was non-toxic, exacerbated APAP-induced hepatotoxicity compared to vehicle-treated controls, causing 80% vs. 0% mortality after administration of a normally sublethal APAP overdose. Of note, Ahr activation induced hepatocyte death even at APAP doses within the therapeutic range. Aggravated liver injury was associated with significant neutrophil infiltration; however, lack of Ahr in myeloid cells did not protect LysM^Δ/ΔAhr mice from exacerbated APAP hepatotoxicity. In contrast, Alb^Δ/ΔAhr mice were largely protected from ITE-induced aggravated liver damage, indicating that Ahr activation in hepatocytes, but not in myeloid cells, was instrumental for disease exacerbation. Mechanistically, Ahr activation fueled hepatic accumulation of toxic APAP metabolites by up-regulating expression of the APAP-metabolizing enzyme Cyp1a2, a direct Ahr downstream target.

CONCLUSIONS

Ahr activation in hepatocytes potentiates APAP-induced hepatotoxicity. Thus, individual exposition to environmental Ahr ligands might explain individual sensitivity to hyperacute liver failure.

Contribution of the Intestinal Microbiome and Gut Barrier to Hepatic Disorders

Intestinal barrier dysfunction and dysbiosis contribute to development of diseases in liver and other organs. Physical, immunologic, and microbiologic (bacterial, fungal, archaeal, viral, and protozoal) features of the intestine separate its nearly 100 trillion microbes from the rest of the human body. Failure of any aspect of this barrier can result in translocation of microbes into the blood and sustained inflammatory response that promote liver injury, fibrosis, cirrhosis, and oncogenic transformation. Alterations in intestinal microbial populations or their functions can also affect health. We review the mechanisms that regulate intestinal permeability and how changes in the intestinal microbiome contribute to development of acute and chronic liver diseases. We discuss individual components of the intestinal barrier and how these are disrupted during development of different liver diseases. Learning more about these processes will increase our understanding of the interactions among the liver, intestine, and its flora.

Indian National Association for the Study of Liver Consensus Statement on Acute Liver Failure (Part-2): Management of Acute Liver Failure

Acute liver failure (ALF) is not an uncommon complication of a common disease such as acute hepatitis. Viral hepatitis followed by antituberculosis drug-induced hepatotoxicity are the commonest causes of ALF in India. Clinically, such patients present with appearance of jaundice, encephalopathy, and coagulopathy. Hepatic encephalopathy (HE) and cerebral edema are central and most important clinical event in the course of ALF, followed by superadded infections, and determine the outcome in these patients. The pathogenesis of encephalopathy and cerebral edema in ALF is unique and multifactorial. Ammonia plays a crucial role in the pathogenesis, and several therapies aim to correct this abnormality. The role of newer ammonia-lowering agents is still evolving. These patients are best managed at a tertiary care hospital with facility for liver transplantation (LT). Aggressive intensive medical management has been documented to salvage a substantial proportion of patients. In those with poor prognostic factors, LT is the only effective therapy that has been shown to improve survival. However, recognizing suitable patients with poor prognosis has remained a challenge. Close monitoring, early identification and treatment of complications, and couseling for transplant form the first-line approach to manage such patients. Recent research shows that use of dynamic prognostic models is better for selecting patients undergoing liver transplantation and timely transplant can save life of patients with ALF with poor prognostic factors.

The gut microbiota regulates autism-like behavior by mediating vitamin B6 homeostasis in EphB6-deficient mice

BACKGROUND

Autism spectrum disorder (ASD) is a developmental disorder, and the effective pharmacological treatments for the core autistic symptoms are currently limited. Increasing evidence, particularly that from clinical studies on ASD patients, suggests a functional link between the gut microbiota and the development of ASD. However, the mechanisms linking the gut microbiota with brain dysfunctions (gut-brain axis) in ASD have not yet been full elucidated. Due to its genetic mutations and downregulated expression in patients with ASD, EPHB6, which also plays important roles in gut homeostasis, is generally considered a candidate gene for ASD. Nonetheless, the role and mechanism of EPHB6 in regulating the gut microbiota and the development of ASD are unclear.

RESULTS

Here, we found that the deletion of EphB6 induced autism-like behavior and disturbed the gut microbiota in mice. More importantly, transplantation of the fecal microbiota from EphB6-deficient mice resulted in autism-like behavior in antibiotic-treated C57BL/6J mice, and transplantation of the fecal microbiota from wild-type mice ameliorated the autism-like behavior in EphB6-deficient mice. At the metabolic level, the disturbed gut microbiota in EphB6-deficient mice led to vitamin B₆ and dopamine defects. At the cellular level, the excitation/inhibition (E/I) balance in the medial prefrontal cortex was regulated by gut microbiota-mediated vitamin B₆ in EphB6-deficient mice.

CONCLUSIONS

Our study uncovers a key role for the gut microbiota in the regulation of autism-like social behavior by vitamin B₆, dopamine, and the E/I balance in EphB6-deficient mice, and these findings suggest new strategies for understanding and treating ASD. Video abstract.

The effect of sorghum resistance resistant starch-mediated equol on the histological morphology of the uterus and ovaries of postmenopausal rats

Equol is a metabolite of daidzein and has a higher biological activity than daidzein. Equol, combined with estrogen receptors, can reduce the incidence of diseases such as cardiovascular disease, osteoporosis, and breast cancer; more effectively alleviate the symptoms of perimenopausal syndrome; and improve age-related decline of the uterus and ovaries. Research has shown that food composition can greatly affect the formation of equol in the intestinal tract. In the intestines, the content of nonstarch polysaccharides that can stimulate fermentation is high, thereby allowing intestinal bacteria to quickly and completely transform the daidzein into equol. This study used Sprague Dawley (SD) rats as a model, where menopause was established through direct intragastric administration of formistan. In the 6-week-long experiment, intragastric administration of RS while feeding bean pulp reduced the body weight of postmenopausal rats, reduced the efficiency of feed utilization of rats, and increased the weight of organs such as the uterus and ovaries. Routine blood indexes showed that no adverse reactions were produced by intragastric administration of RS. 16s rDNA sequencing further verified Lactobacillus and Clostridium XIVa, as the bacteria that converted daidzein into equol.

Gut Microbiota and Liver Injury (I)-Acute Liver Injury

Over the last few decades, intestinal microbial communities have been considered to play a vital role in host liver health. Acute liver injury (ALI) is the manifestation of sudden hepatic injury and arises from a variety of causes. The studies of dysbiosis in gut microbiota provide new insight into the pathogenesis of ALI. However, the relationship of gut microbiota and ALI is not well understood, and the contribution of gut microbiota to ALI has not been well characterized. In this chapter, we integrate several major pathogenic factors in ALI with the role of gut microbiota to stress the significance of gut microbiota in prevention and treatment of ALI.

Indian National Association for the Study of the Liver Consensus Statement on Acute Liver Failure (Part 1): Epidemiology, Pathogenesis, Presentation and Prognosis

Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.

The resistant starch from sorghum regulates lipid metabolism in menopausal rats via equol

Equol is a metabolite of daidzein and has a higher biological activity than daidzein. High levels of non-starch polysaccharides can stimulate fermentation in the intestine leading to rapid conversion of daidzein into equol that has great potential to reduce obesity in postmenopausal women. In the present study, female Sprague-Dawley rats were used to establish a menopausal model by oral administration of formestane and to compare the protective effect of resistant starch on lipid metabolism, with or without soybean feed. The resistant starch was found to effectively control body weight and adipose tissue quality, while increasing the high-density lipoprotein cholesterol (HDL-C) concentration and lowering the glycerol, triacylglycerols (TG), total cholesterol (TC), and low density lipoprotein cholesterol (LDL-C) concentrations with soybean feed. Equol inhibited the expression of SREBPC1 gene by inhibiting SHP in the liver via transcription factor FXR, thereby inhibiting the synthesis of triglyceride and fatty acid in the liver. PRACTICAL APPLICATIONS: Intake of a certain amount of resistant starch while eating the soy product can better regulate lipid metabolism in menopausal obese rats compared to consumption of resistant starch alone. Studies have shown that resistant starch converts daidzein to Equol by regulating the structure of the intestinal flora and acts as an estrogen in menopausal rats. This research will further expand the health applications of resistant starch and provide useful information for the food industry.

The Gut-liver Axis in Immune Remodeling: New insight into Liver Diseases

The gut microbiota consists of a dynamic multispecies community of bacteria, fungi, archaea, and protozoans, playing a fundamental role in the induction, training, and function of the host immune system. The liver is anatomically and physiologically linked to the gut microbiota via enterohepatic circulation, specifically receiving intestine-derived blood through the portal vein. The gut microbiota is crucial for maintaining immune homeostasis of the gut-liver axis. A shift in gut microbiota composition can result in activation of the mucosal immune response causing homeostasis imbalance. This imbalance results in translocation of bacteria and migration of immune cells to the liver, which is related to inflammation-mediated liver injury and tumor progression. In this review, we outline the role of the gut microbiota in modulating host immunity and summarize novel findings and recent advances in immune-based therapeutics associated with the gut-liver axis. Moving forward, a deep understanding of the microbiome-immune-liver axis will provide insight into the basic mechanisms of gut microbiota dysbiosis affecting liver diseases.

Sinomenine Attenuates Acetaminophen-Induced Acute Liver Injury by Decreasing Oxidative Stress and Inflammatory Response via Regulating TGF-β/Smad Pathway in vitro and in vivo

Introduction

Liver disease is common and often life-threatening. Sinomenine (SIN) is an active ingredient extracted from  Sinomenium acutum. This study investigated the protective effect and mechanism of sinomenine (SIN) on acetaminophen (APAP)-induced liver injury from in vitro and in vivo.

Methods

In vivo experiments, mice were randomly divided into six groups (n=10): control group, model group, SIN (25 mg/kg) group, SIN (50 mg/kg) group, SIN (100 mg/kg) group and SIN (100 mg/kg) + SRI-011381 group. Alanine transaminases (ALT), aspartate transaminases (AST) and alkaline phosphatase (ALP) were detected. The pathological lesion was measured by HE staining. Apoptosis was measured by TUNEL staining. In vitro experiments, BRL-3A cells were treated with APAP (7.5 mM) and then subjected to various doses of SIN (10, 50 and 100 μg/mL) at 37°C for 24 h. Inflammatory factors and oxidative stress index were measured by ELISA. The expression of proteins was detected by Western blot.

Results

The results showed that compared with the control group, the levels of ALT, AST and ALP in the serum of APAP-induced mice were significantly increased, followed by liver histological damage and hepatocyte apoptosis. Besides, APAP reduced the activity of SOD and GSH-Px, while increasing the content of MDA and LDH. Notably, APAP also promoted the expression of NLRP3, ASC, caspase-1 and IL-1β. Interestingly, SIN treatment dose-dependently reduced APAP-induced liver injury and oxidative stress, inhibited the activation of NLRP3 inflammasomes, and reduced the levels of inflammatory cytokines. In vitro studies have shown that SIN treatment significantly reduced the viability of BRL-3A cells and oxidative stress and inflammation. In addition, the Western blotting analysis showed that SIN inhibited the activation of TGF-β/Smad pathway in a dose-dependent manner in vitro and in vivo. These effects were significantly reversed by TGF-β/Smad activator SRI-011381 or TGF-β overexpression.

Discussion

The study indicates that SIN attenuates APAP-induced acute liver injury by decreasing oxidative stress and inflammatory response via TGF-β/Smad pathway in vitro and in vivo.

Intestinal Flora as a Potential Strategy to Fight SARS-CoV-2 Infection

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread rapidly worldwide, seriously endangering human health. In addition to the typical symptoms of pulmonary infection, patients with COVID-19 have been reported to have gastrointestinal symptoms and/or intestinal flora dysbiosis. It is known that a healthy intestinal flora is closely related to the maintenance of pulmonary and systemic health by regulating the host immune homeostasis. Role of the "gut-lung axis" has also been well-articulated. This review provides a novel suggestion that intestinal flora may be one of the mediators of the gastrointestinal responses and abnormal immune responses in hosts caused by SARS-CoV-2; improving the composition of intestinal flora and the proportion of its metabolites through probiotics, and personalized diet could be a potential strategy to prevent and treat COVID-19. More clinical and evidence-based medical trials may be initiated to determine the strategy.

Colonization Potential to Reconstitute a Microbe Community in Pseudo Germ-Free Mice After Fecal Microbe Transplant From Equol Producer

Human intestinal microbiota plays a crucial role in the conversion of isoflavones into equol. Usually, human microbiota-associated (HMA) animal models are used, since it is difficult to establish the mechanism and causal relationship between equol and microbiota in human studies. Currently, several groups have successfully established HMA animal models that produce equol through germ-free mice or rats; however, the HMA model of producing equol through pseudo germ-free mice has not been established. The objective of this study is to establish an HMA mice model for equol production through pseudo germ-free mice, mimicking the gut microbiota of an adult human equol producer. First, a higher female equol producer was screened as a donor from 15 volunteers. Then, mice were exposed to vancomycin, neomycin sulfate, metronidazole, and ampicillin for 3 weeks to obtain pseudo germ-free mice. Finally, pseudo germ-free mice were inoculated with fecal microbiota of the equol producer for 3 weeks to establish HMA mice of producing equol. The results showed that (i) the ability to produce equol was partially transferred from the donor to the HMA mice. (ii) Most of the original intestinal microbiota of mice were eliminated after broad-spectrum antibiotic administration. (iii) The taxonomy data from HMA mice revealed similar taxa to the donor sample, and the species richness returned to the level close to the donor. (iv) The family Coriobacteriaceae and genera Collinsella were successfully transferred from the donor to HMA mice. In conclusion, the HMA mice model for equol production, based on pseudo germ-free mice, can replace the model established by germ-free mice. The model also provides a basis for studying microbiota during the conversion from isoflavones into equol.

Vital members in the gut microbiotas altered by two probiotic Bifidobacterium strains against liver damage in rats

Background

Probiotics are effective to rectify the imbalanced gut microbiota in the diseased cohorts. Two Bifidobacterium strains (LI09 and LI10) were found to alleviate D-galactosamine-induced liver damage (LD) in rats in our previous work. A series of bioinformatic and statistical analyses were performed to determine the vital bacteria in the gut microbiotas altered by the LI09 or LI10 in rats.

Results

Two groups of representative phylotypes could distinguish the gut microbiotas of LI09 or LI10 groups from the other groups. Among them, OTU170_Porphyromonadaceae acted as a gatekeeper in LI09 group, while OTU12_Bacteroides was determined with multiple correlations in the gut network of LI10 group. Multiple reduced OTUs associated with LC and increased OTUs associated with health were determined in LI09 or LI10 groups, among which, increased OTU51_Barnesiella and reduced OTU99_Barnesiella could be associated with the protective effects of both the two probiotics. The gut microbiotas in LI09, LI10 and positive control groups were clustered into three clusters, i.e., Cluster_1_Microbiota, Cluster_2_Microbiota and Cluster_3_Microbiota, by Partition Around Medoids clustering analysis. Cluster_2_Microbiota was determined at least dysbiotic status due to its greatest LD dysbiosis ratio, lowest levels of liver function variables and plasma cytokines compared with the two other clustered microbiotas, suggesting the treated rats in Cluster_2 were at better health status.

Conclusion

Our findings suggest that OTU170_Porphyromonadaceae and OTU12_Bacteroides are vital in the gut microbiotas altered by LI09 and LI10. Characteristics of the LD cohorts treated by LI09 or LI10 at different gut microbial colonization states could help monitor the cohorts’ health status.

The Microbiome as a Circadian Coordinator of Metabolism

The microbiome is critically involved in the regulation of systemic metabolism. An important but poorly understood facet of this regulation is the diurnal activity of the microbiome. Herein, we summarize recent developments in our understanding of the diurnal properties of the microbiome and their integration into the circadian regulation of organismal metabolism. The microbiome may be involved in the detrimental consequences of circadian disruption for host metabolism and the development of metabolic disease. At the same time, the mechanisms by which microbiome diurnal activity is integrated into host physiology reveal several translational opportunities by which the time of day can be harnessed to optimize microbiome-based therapies. The study of circadian microbiome properties may thus provide a new avenue for treating disorders associated with circadian disruption from the gut.

[Gut microbiota-an important contributor to liver diseases]

Gut microbiota constitute a complicated but manifold ecosystem, in which specific symbiotic relationships are formed among various bacteria. To maintain a steady state, the gastrointestinal tract and the liver form a close anatomical and functional two-way, interconnected network through the portal circulation. "Gut-liver axis" plays a key role in the pathogenesis of liver diseases. Accumulating evidence indicates that gut microbiota can influence the liver pathophysiology directly or indirectly via a variety of signal pathways. In a pathological state where an ecological imbalance occurs at the compositional and functional levels, gut microbes would interact with the host immune system and other type of cells to cause liver steatosis, inflammation and fibrosis, which in turn give rise to the development of such liver diseases as alcoholic liver disease, nonalcoholic fatty liver disease, primary sclerosing cholangitis, and acute liver failure, to name a few. Studies have shown that microorganisms, such as prebiotics and probiotics, can improve the prognosis of certain diseases, which open a new era of treating liver diseases with bacteria. There are many unknowns and hidden values in the gut microbiome. To explore the pathophysiological mechanism of various complex diseases and develop scientific and effective clinical treatment strategies, efforts should be made to obtain insights into how certain intestinal microbiota participates in the occurrence and progression of liver diseases. As the connection between gut microbiota and liver diseases at both the acute and chronic phases was not elaborated in previously published review articles, herein we discuss the association between gut microbiota and both acute and chronic liver injury. The anatomical structure of the liver enables it to form a close network with the gut microbiota, which is an important mediator in the regulation of the hepatic physiological and pathological functions.

Nanodrug with ROS and pH Dual-Sensitivity Ameliorates Liver Fibrosis via Multicellular Regulation

Liver fibrosis currently represents a global health problem without effective pharmacotherapeutic strategies. The clinical translation of polydatin, a promising natural anti-fibrotic drug candidate with broad anti-inflammatory and antioxidant capabilities, remains a major challenge due to its limited water solubility and tissue absorption. Herein, a polydatin-loaded micelle (PD-MC) based on reactive oxygen species (ROS) and pH dual-sensitive block polymer PEG-P(PBEM-co-DPA) is developed. The micelle exerts great potential in improving the biocompatibility of polydatin and shows highly efficient liver-targeted drug release in response to the fibrotic microenvironment. Both in vitro and in vivo studies demonstrate that PD-MC can significantly suppress inflammatory response and oxidative stress, reduce hepatocyte apoptosis, and avert activation of macrophages and hepatic stellate cells. More excitingly, the blank micelle itself promotes the hepatic ROS consumption at the pathologic site to provide anti-inflammatory benefits. These favorable therapeutic virtues of targeting multiple cell types endow PD-MC with remarkable efficacy with minimal side effects in liver fibrosis treatment. Thus, PD-MC holds great potential to push forward the clinical application of polydatin in pharmacotherapeutic approaches against liver fibrosis.

Modulating the Intestinal Microbiota: Therapeutic Opportunities in Liver Disease

Gut microbiota has been demonstrated to have a significant impact on the initiation, progression and development of complications associated with multiple liver diseases. Notably, nonalcoholic fatty liver diseases, including nonalcoholic steatohepatitis and cirrhosis, severe alcoholic hepatitis, primary sclerosing cholangitis and hepatic encephalopathy, have strong links to dysbiosis - or a pathobiological change in the microbiota. In this review, we provide clear and concise discussions on the human gut microbiota, methods of identifying gut microbiota and its functionality, liver diseases that are affected by the gut microbiota, including novel associations under research, and provide current evidence on the modulation of gut microbiota and its effects on specific liver disease conditions.

Herbal Therapy for the Treatment of Acetaminophen-Associated Liver Injury: Recent Advances and Future Perspectives

Acetaminophen (APAP) overdose is the leading cause of drug-induced liver injury worldwide, and mitochondrial oxidative stress is considered the major event responsible for APAP-associated liver injury (ALI). Despite the identification of N-acetyl cysteine, a reactive oxygen species scavenger that is regarded as an effective clinical treatment, therapeutic effectiveness remains limited due to rapid disease progression and diagnosis at a late phase, which leads to the need to explore various therapeutic approaches. Since the early 1990s, a number of natural products and herbs have been found to have hepatoprotective effects against APAP-induced hepatotoxicity in terms of acute liver failure prevention and therapeutic amelioration of ALI. In this review, we summarize the hepatoprotective effects and mechanisms of medicinal plants, including herbs and fruit extracts, along with future perspectives that may provide guidance to improve the current status of herbal therapy against ALI.

Microbes in the Era of Circadian Medicine

The organisms of most domains of life have adapted to circadian changes of the environment and regulate their behavior and physiology accordingly. A particular case of such paradigm is represented by some types of host-pathogen interaction during infection. Indeed, not only some hosts and pathogens are each endowed with their own circadian clock, but they are also influenced by the circadian changes of the other with profound consequences on the outcome of the infection. It comes that daily fluctuations in the availability of resources and the nature of the immune response, coupled with circadian changes of the pathogen, may influence microbial virulence, level of colonization and damage to the host, and alter the equilibrium between commensal and invading microorganisms. In the present review, we discuss the potential relevance of circadian rhythms in human bacterial and fungal pathogens, and the consequences of circadian changes of the host immune system and microbiome on the onset and development of infection. By looking from the perspective of the interplay between host and microbes circadian rhythms, these concepts are expected to change the way we approach human infections, not only by predicting the outcome of the host-pathogen interaction, but also by indicating the best time for intervention to potentiate the anti-microbial activities of the immune system and to weaken the pathogen when its susceptibility is higher.

Intestinal Epithelial Chemokine (C-C Motif) Ligand 7 Overexpression Enhances Acetaminophen-Induced Hepatotoxicity in Mice

Acetaminophen (APAP) overdose-induced hepatotoxicity is the leading cause of drug-induced liver injury worldwide. The related injury pathogenesis is mainly focused on the liver. Here, the authors report that gut barrier disruption may also be involved in APAP hepatotoxicity. APAP administration led to gut leakiness and colonic epithelial chemokine (C-C motif) ligand 7 (CCL7) up-regulation. Intestinal epithelial cell (IEC)-specific CCL7 transgenic mice (CCL7tgIEC mice) showed markedly increased myosin light chain kinase phosphorylation, and elevated gut permeability and bacterial translocation into the liver compared to wild-type mice. Global transcriptome analysis revealed that the expression of hepatic proinflammatory genes was enhanced in CCL7tgIEC mice compared with wild-type animals. Moreover, CCL7 overexpression in intestinal epithelial cells significantly augmented APAP-induced acute liver injury. These data provide new evidence that dysfunction of CCL7-mediated gut barrier integrity may be an important contributor to APAP-induced hepatotoxicity.

Application of LpxC enzyme inhibitor to inhibit some fast-growing bacteria in human gut bacterial culturomics

BACKGROUND

Culturomics can ascertain traces of microorganisms to be cultivated using different strategies and identified by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry or 16S rDNA sequencing. However, to cater to all requirements of microorganisms and isolate as many species as possible, multiple culture conditions must be used, imposing a heavy workload. In addition, the fast-growing bacteria (e.g., Escherichia) surpass the slow-growing bacteria in culture by occupying space and using up nutrients. Besides, some bacteria (e.g., Pseudomonas) suppress others by secreting antibacterial metabolites, making it difficult to isolate bacteria with lower competence. Applying inhibitors to restrain fast-growing bacteria is one method to cultivate more bacterial species from human feces.

RESULTS

We applied CHIR-090, an LpxC enzyme inhibitor that has antibacterial activity against most Gram-negative bacteria, to culturomics of human fresh feces. The antibacterial activity of CHIR-090 was first assessed on five Gram-negative species of bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, and Bacteroides vulgatus), all of which are commonly isolated from the human gut. Then, we assessed suitable concentrations of the inhibitor. Finally, CHIR-090 was applied in blood culture bottles for bacterial cultivation. In total, 102 species from five samples were identified. Of these, we found one new species, two species not reported previously in the human gut, and 11 species not previously isolated from humans.

CONCLUSIONS

CHIR-090 can suppress E. coli, P. aeruginosa, K. pneumoniae, Pro. vulgaris, but not B. vulgatus. Compared with the non-inhibitor group, CHIR-090 increased bacteria isolation by 23.50%, including four species not reported in humans and one new species. Application of LpxC enzyme inhibitor in culturomics increased the number of species isolated from the human gut.

Mechanisms of gastrointestinal microflora on drug metabolism in clinical practice

Considered as an essential "metabolic organ", intestinal microbiota plays a key role in human health and the predisposition to diseases. It is an aggregate genome of trillions of microorganisms residing in the human gastrointestinal tract. Since the 20th century, researches have showed that intestinal microbiome possesses a variety of metabolic activities that are able to modulate the fate of more than 30 approved drugs and immune checkpoint inhibitors. These drugs are transformed to bioactive, inactive, or toxic metabolites by microbial direct action or host-microbial co-metabolism. These metabolites are responsible for therapeutic effects exerted by these drugs or side effects induced by these drugs, even for death. In view of the significant effect on the drugs metabolism by the gut microbiota, it is pivotal for personalized medicine to explore additional drugs affected by gut microbiota and their involved strains for further making mechanism clear through suitable animal models. This review mainly focus on specific mechanisms involved, with reference to the current literature about drugs metabolism by related bacteria or its enzymes available.

Vancomycin pretreatment attenuates acetaminophen-induced liver injury through 2-hydroxybutyric acid

Liver injury caused by acetaminophen (AP) overdose is a leading public health problem. Although AP-induced liver injury is well recognized as the formation of N-acetyl-p-benzoquinone (NAPQI), a toxic metabolite of AP, resulting in cell damage, emerging evidence indicates that AP-induced liver injury is also associated with gut microbiota. However, the gut microbiota-involved mechanism remains largely unknown. In our study, we found that vancomycin (Vac) pretreatment (100 mg/kg, twice a day for 4 days) attenuated AP-induced liver injury, altered the composition of gut microbiota, and changed serum metabolic profile. Moreover, we identified Vac pretreatment elevated cecum and serum 2-hydroxybutyric acid (2-HB), which ameliorated AP-induced cell damage and liver injury in mice by reducing AP bioavailability and elevating GSH levels. Our current results revealed the novel role of 2-HB in protecting AP-induced liver injury and add new evidence for gut microbiota in affecting AP toxicity.

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Vac pretreatment attenuated AP-induced liver injury in rats.

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Vac pretreatment elevated metabolite 2-HB both in cecum and serum.

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2-HB attenuated the AP-induced hepatotoxicity both in vitro and in vivo.

Gut Abnormalities: New Insights Into the Pathogenesis of Acetaminophen-Induced Liver Injury?

This editorial comment is for the study entitled "Acetaminophen intoxication rapidly induces apoptosis of intestinal crypt stem cells and enhances intestinal permeability" which will be published on Hepatology Communications.

Intestinal Microbiota-Associated Metabolites: Crucial Factors in the Effectiveness of Herbal Medicines and Diet Therapies

Although the efficacy of herbal medicines (HMs) and traditional Chinese medicines (TCMs) in human diseases has long been recognized, their development has been hindered in part by a lack of a comprehensive understanding of their mechanisms of action. Indeed, most of the compounds extracted from HMs can be metabolized into specific molecules by host microbiota and affect pharmacokinetics and toxicity. Moreover, HMs modulate the constitution of host intestinal microbiota to maintain a healthy gut ecology. Dietary interventions also show great efficacy in treating some refractory diseases, and the commensal microbiota potentially has significant implications for the high inter-individual differences observed in such responses. Herein, we mainly discuss the contribution of the intestinal microbiota to high inter-individual differences in response to HMs and TCMs, and especially the already known metabolites of the HMs produced by the intestinal microbiota. The contribution of commensal microbiota to the inter-individual differences in response to dietary therapy is also briefly discussed. This review highlights the significance of intestinal microbiota-associated metabolites to the efficiency of HMs and dietary interventions. Our review may help further identify the mechanisms leading to the inter-individual differences in the effectiveness of HM and dietary intervention from the perspective of their interactions with the intestinal microbiota.

Demystifying the manipulation of host immunity, metabolism, and extraintestinal tumors by the gut microbiome

The trillions of microorganisms in the gut microbiome have attracted much attention recently owing to their sophisticated and widespread impacts on numerous aspects of host pathophysiology. Remarkable progress in large-scale sequencing and mass spectrometry has increased our understanding of the influence of the microbiome and/or its metabolites on the onset and progression of extraintestinal cancers and the efficacy of cancer immunotherapy. Given the plasticity in microbial composition and function, microbial-based therapeutic interventions, including dietary modulation, prebiotics, and probiotics, as well as fecal microbial transplantation, potentially permit the development of novel strategies for cancer therapy to improve clinical outcomes. Herein, we summarize the latest evidence on the involvement of the gut microbiome in host immunity and metabolism, the effects of the microbiome on extraintestinal cancers and the immune response, and strategies to modulate the gut microbiome, and we discuss ongoing studies and future areas of research that deserve focused research efforts.

Enteric dysbiosis is associated with sepsis in patients

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to microbial infection. For decades, the potential role of gut microbiota in sepsis pathogenesis has been revealed. However, the systemic and functional link between gut microbiota and sepsis has remained unexplored. To address this gap in knowledge, we carried out systematic analyses on clinical stool samples from patients with sepsis, including 16S rDNA sequencing, metabolomics, and metaproteomics analyses. In addition, we performed fecal microbiota transplantation from human to mice to validate the roles of gut microbiota on sepsis progression. We found that the composition of gut microbiota was significantly disrupted in patients with sepsis compared with healthy individuals. Besides, the microbial functions were significantly altered in septic feces as identified by metabolomics and metaproteomics analyses. Interestingly, mice that received septic feces exhibited more severe hepatic inflammation and injury than mice that received healthy feces after cecal ligation and puncture. Finally, several strains of intestinal microbiota and microbial metabolites were corelated with serum total bilirubin levels in patients with sepsis. Taken together, our data indicated that sepsis development is associated with the disruption of gut microbiota at both compositional and functional levels, and such enteric dysbiosis could promote organ inflammation and injury during sepsis.-Liu, Z., Li, N., Fang, H., Chen, X., Guo, Y., Gong, S., Niu, M., Zhou, H., Jiang, Y., Chang, P., Chen, P. Enteric dysbiosis is associated with sepsis in patients.

Drug-induced liver injury

Drug-induced liver injury (DILI) is an adverse reaction to drugs or other xenobiotics that occurs either as a predictable event when an individual is exposed to toxic doses of some compounds or as an unpredictable event with many drugs in common use. Drugs can be harmful to the liver in susceptible individuals owing to genetic and environmental risk factors. These risk factors modify hepatic metabolism and excretion of the DILI-causative agent leading to cellular stress, cell death, activation of an adaptive immune response and a failure to adapt, with progression to overt liver injury. Idiosyncratic DILI is a relative rare hepatic disorder but can be severe and, in some cases, fatal, presenting with a variety of phenotypes, which mimic other hepatic diseases. The diagnosis of DILI relies on the exclusion of other aetiologies of liver disease as specific biomarkers are still lacking. Clinical scales such as CIOMS/RUCAM can support the diagnostic process but need refinement. A number of clinical variables, validated in prospective cohorts, can be used to predict a more severe DILI outcome. Although no pharmacological therapy has been adequately tested in randomized clinical trials, corticosteroids can be useful, particularly in the emergent form of DILI related to immune-checkpoint inhibitors in patients with cancer.

Acetaminophen Intoxication Rapidly Induces Apoptosis of Intestinal Crypt Stem Cells and Enhances Intestinal Permeability

Acetaminophen (APAP)‐induced liver injury is the most common cause of acute liver failure (ALF) in the Western world. APAP toxicity progresses to multiorgan dysfunction and thus has broader whole‐body implications. Importantly, greater 30‐day mortality has been observed in liver transplant recipients following ALF due to APAP‐related versus non‐APAP‐related causes. Reasons for this discrepancy have yet to be determined. Extrahepatic toxicities of APAP overdose may represent underappreciated and unaddressed comorbidities within this patient population. In the present study, rapid induction of apoptosis following APAP overdose was observed in the intestine, an organ that greatly influences the physiology of the liver. Strikingly, apoptotic cells appeared to be strictly restricted to the intestinal crypts. The use of leucine‐rich repeat‐containing G protein–coupled receptor 5 (LGR5) reporter mice confirmed that the LGR5‐positive (+) crypt base stem cells were disproportionately affected by APAP‐induced cell death. Although the apoptotic cells were cleared within 24 hours after APAP treatment, potentially long‐lived consequences on the intestine due to APAP exposure were indicated by prolonged deficits in gut barrier function. Moreover, small intestinal cell death was found to be independent of tumor necrosis factor receptor signaling and may represent a direct toxic insult to the intestine by exposure to high concentrations of APAP. Conclusion: APAP induces intestinal injury through a regulated process of apoptotic cell death that disproportionately affects LGR5⁺ stem cells. This work advances our understanding of the consequences of APAP toxicity in a novel organ that was not previously considered as a significant site of injury and thus presents potential new considerations for patient management.

Human microbial ecology and the rising new medicine

The first life forms on earth were Prokaryotic, and the evolution of all Eukaryotic life occurred with the help of bacteria. Animal-associated microbiota also includes members of the archaea, fungi, protists, and viruses. The genomes of this host-associated microbial life are called the microbiome. Across the mammalian tree, microbiomes guarantee the development of immunity, physiology, and resistance to pathogens. In humans, all surfaces and cavities are colonized by a microbiome, maintained by a careful balance between the host response and its colonizers-thus humans are considered now supraorganisms. These microbiomes supply essential ecosystem services that benefit health through homeostasis, and the loss of the indigenous microbiota leads to dysbiosis, which can have significant consequences to disease. This educational review aims to describe the importance of human microbial ecology, explain the ecological terms applied to the study of the human microbiome, developments within the cutting-edge microbiome field, and implications to diagnostic and treatment.

Hepatocyte growth control by SOCS1 and SOCS3

The extraordinary capacity of the liver to regenerate following injury is dependent on coordinated and regulated actions of cytokines and growth factors. Whereas hepatocyte growth factor (HGF) and epidermal growth factor (EGF) are direct mitogens to hepatocytes, inflammatory cytokines such as TNFα and IL-6 also play essential roles in the liver regeneration process. These cytokines and growth factors activate different signaling pathways in a sequential manner to elicit hepatocyte proliferation. The kinetics and magnitude of these hepatocyte-activating stimuli are tightly regulated to ensure restoration of a functional liver mass without causing uncontrolled cell proliferation. Hepatocyte proliferation can become deregulated under conditions of chronic inflammation, leading to accumulation of genetic aberrations and eventual neoplastic transformation. Among the control mechanisms that regulate hepatocyte proliferation, negative feedback inhibition by the 'suppressor of cytokine signaling (SOCS)' family proteins SOCS1 and SOCS3 play crucial roles in attenuating cytokine and growth factor signaling. Loss of SOCS1 or SOCS3 in the mouse liver increases the rate of liver regeneration and renders hepatocytes susceptible to neoplastic transformation. The frequent epigenetic repression of the SOCS1 and SOCS3 genes in hepatocellular carcinoma has stimulated research in understanding the growth regulatory mechanisms of SOCS1 and SOCS3 in hepatocytes. Whereas SOCS3 is implicated in regulating JAK-STAT signaling induced by IL-6 and attenuating EGFR signaling, SOCS1 is crucial for the regulation of HGF signaling. These two proteins also module the functions of certain key proteins that control the cell cycle. In this review, we discuss the current understanding of the functions of SOCS1 and SOCS3 in controlling hepatocyte proliferation, and its implications to liver health and disease.

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.

A toll-like receptor 9 agonist sensitizes mice to mitochondrial dysfunction-induced hepatic apoptosis via the Fas/FasL pathway

Early hepatocyte death occurs in most liver injury cases and triggers liver inflammation, which in combination with other risk factors leads to the development of liver disease. However, the pathogenesis of early phase hepatocyte death remains poorly understood. Here, C57BL/6J mice were treated with the hepatotoxic drug flucloxacillin (FLUX) and the toll-like receptor 9 agonist CpG oligodeoxynucleotide (ODN) to reproduce the early phase of drug-induced hepatotoxicity and investigate its pathogenesis. C57BL/6J mice were treated with FLUX (100 mg/kg, gavage) alone or in combination with ODN (40 μg/mouse, intraperitoneally). Plasma alanine aminotransferase (ALT) level was measured as a marker of hepatotoxicity. FLUX or ODN alone was insufficient to induce ALT elevation, whereas combination treatment with FLUX and ODN increased ALT levels 24 h after FLUX treatment and upregulated Fas ligand in natural killer T (NKT) cells and Fas in hepatocytes. FLUX induced mitochondrial permeability transition (MPT), and pretreatment with ODN sensitized mitochondria to FLUX-induced MPT. The increase in ALT levels induced by ODN and FLUX co-treatment was suppressed in Fas ligand (gld/gld)-deficient mice and in mice deficient in a component of MPT pore opening (cyclophilin D-knockout mice). These results suggested that ODN activated the Fas/Fas ligand-mediated pathway in NKT cells and hepatocytes, which may predispose to FLUX-induced mitochondrial dysfunction and lead to early phase hepatocyte apoptosis. Taken together, these findings elucidate a potentially novel mechanism underlying drug-induced early phase hepatocyte death related to the Fas/Fas ligand death receptor pathway and mitochondrial dysfunction.

Intestinal Microbiota Mediates the Susceptibility to Polymicrobial Sepsis-Induced Liver Injury by Granisetron Generation in Mice

Sepsis-induced liver injury is recognized as a key problem in intensive care units. The gut microbiota has been touted as an important mediator of liver disease development; however, the precise roles of gut microbiota in regulating sepsis-induced liver injury are unknown. Here, we aimed to investigate the role of the gut microbiota in sepsis-induced liver injury and the underlying mechanism. Cecal ligation and puncture (CLP) was used to induce polymicrobial sepsis and related liver injury. Fecal microbiota transplantation (FMT) was used to validate the roles of gut microbiota in these pathologies. Metabolomics analysis was performed to characterize the metabolic profile differences between sepsis-resistant (Res; survived to 7 days after CLP) and sepsis-sensitive (Sen; moribund before or approximately 24 hours after CLP) mice. Mice gavaged with feces from Sen mice displayed more-severe liver damage than did mice gavaged with feces from Res mice. The gut microbial metabolic profile between Sen and Res mice was different. In particular, the microbiota from Res mice generated more granisetron, a 5-hydroxytryptamine 3 (5-HT₃ ) receptor antagonist, than the microbiota from Sen mice. Granisetron protected mice against CLP-induced death and liver injury. Moreover, proinflammatory cytokine expression by macrophages after lipopolysaccharide (LPS) challenge was markedly reduced in the presence of granisetron. Both treatment with granisetron and genetic knockdown of the 5-HT_3A receptor in cells suppressed nuclear factor kappa B (NF-кB) transactivation and phosphorylated p38 (p-p38) accumulation in macrophages. Gut microbial granisetron levels showed a significantly negative correlation with plasma alanine aminotransferase (ALT)/aspartate aminotransferase (AST) levels in septic patients. Conclusion: Our study indicated that gut microbiota plays a key role in the sensitization of sepsis-induced liver injury and associates granisetron as a hepatoprotective compound during sepsis development.

Second exposure to acetaminophen overdose is associated with liver fibrosis in mice

Repeated administration of hepatotoxicants is usually accompanied by liver fibrosis. However, the difference in response as a result of repeated exposures of acetaminophen (APAP) compared to a single dose is not well-studied. Therefore, in the current study, the liver response after a second dose of APAP was investigated. Adult fasted Balb/C mice were exposed to two toxic doses of 300 mg/kg APAP, which were administered 72 h apart from each other. Subsequently, blood and liver from the treated mice were collected 24 h and 72 h after both APAP administrations. Liver transaminase, i.e. alanine amino transferase (ALT) and aspartate amino transferase (AST) levels revealed that the fulminant liver damage was reduced after the second APAP administration compared to that observed at the same time point after the first treatment. These results correlated with the necrotic areas as indicated by histological analyses. Surprisingly, Picro Sirius Red (PSR) staining showed that the accumulation of extracellular matrix after the second dose coincides with the upregulation of some fibrogenic signatures, e.g., alpha smooth muscle actin. Non-targeted liver tissue metabolic profiling indicates that most alterations occur 24 h after the first dose of APAP. However, the levels of most metabolites recover to basal values over time. This organ adaptation process is also confirmed by the upregulation of antioxidative systems like e.g. superoxide dismutase and catalase. From the results, it can be concluded that there is a different response of the liver to APAP toxic doses, if the liver has already been exposed to APAP. A necroinflammatory process followed by a liver regeneration was observed after the first APAP exposure. However, fibrogenesis through the accumulation of extracellular matrix is observed after a second challenge. Therefore, further studies are required to mechanistically understand the so called "liver memory".

Acute Liver Failure: From Textbook to Emergency Room and Intensive Care Unit With Concomitant Established and Modern Novel Therapies

Acute liver failure is a rare hepatic emergent situation that affects primarily young people and has often a catastrophic or even fatal outcome. Definition of acute liver failure has not reached a universal consensus and the interval between the appearance of jaundice and hepatic encephalopathy for the establishment of the acute failure is a matter of debate. Among the wide variety of causes, acetaminophen intoxication in western societies and viral hepatitis in the developing countries rank at the top of the etiology list. Identification of the clinical appearance and initial management for the stabilization of the patient are of vital significance. Further advanced therapies, that require intensive care unit, should be offered. The hallmark of treatment for selected patients can be orthotopic liver transplantation. Apart from well-established treatments, novel therapies like hepatocyte or stem cell transplantation, additional new therapeutic strategies targeting acetaminophen intoxication and/or hepatic encephalopathy are mainly experimental, and some of them do not belong, yet, to clinical practice. For clinicians, it is substantial to have the alertness to timely identify the patient and transfer them to a specialized center, where more treatment opportunities are available.

Fucoidan Alleviates Acetaminophen-Induced Hepatotoxicity via Oxidative Stress Inhibition and Nrf2 Translocation

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug that leads to severe hepatotoxicity at excessive doses. Fucoidan, a sulfated polysaccharide derived from brown seaweeds, possesses a wide range of pharmacological properties. However, the impacts of fucoidan on APAP-induced liver injury have not been sufficiently addressed. In the present study, male Institute of Cancer Research (ICR) mice aged 6 weeks were subjected to a single APAP (500 mg/kg) intraperitoneal injection after 7 days of fucoidan (100 or 200 mg/kg/day) or bicyclol intragastric administration. The mice continued to be administered fucoidan or bicyclol once per day, and were sacrificed at an indicated time. The indexes evaluated included liver pathological changes, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT) in the liver, and related proteins levels (CYP2E1, pJNK and Bax). Furthermore, human hepatocyte HL-7702 cell line was used to elucidate the potential molecular mechanism of fucoidan. The mitochondrial membrane potential (MMP) and nuclear factor-erythroid 2-related factor (Nrf2) translocation in HL-7702 cells were determined. The results showed that fucoidan pretreatment reduced the levels of ALT, AST, ROS, and MDA, while it enhanced the levels of GSH, SOD, and CAT activities. Additionally, oxidative stress-induced phosphorylated c-Jun N-terminal protein kinase (JNK) and decreased MMP were attenuated by fucoidan. Although the nuclear Nrf2 was induced after APAP incubation, fucoidan further enhanced Nrf2 in cell nuclei and total expression of Nrf2. These results indicated that fucoidan ameliorated APAP hepatotoxicity, and the mechanism might be related to Nrf2-mediated oxidative stress.

L-Fucose ameliorates high-fat diet-induced obesity and hepatic steatosis in mice

Background

l-Fucose (Fuc), a six-deoxy hexose monosaccharide, is present endogenously in humans and animals and has a wide range of biological functions. In the present study, we aimed to examine the effect of Fuc on obesity and hepatic steatosis in mice fed a high-fat diet (HFD).

Methods

C57BL/6 mice were fed a normal chow (NC) or HFD for 18 weeks to induce obesity and fatty liver. Fuc was administered intragastrically from the 8th week to the end of the experiment (18 weeks).

Results

Metagenomic analysis showed that HFD altered the genomic profile of gut microbiota in the mice; specifically, expression of alpha-l-fucosidase, the gene responsible for Fuc generation, was markedly reduced in the HFD group compared with that in the NC group. Fuc treatment decreased body weight gain, fat accumulation, and hepatic triglyceride elevation in HFD-fed mice. In addition, Fuc decreased the levels of endotoxin-producing bacteria of the Desulfovibrionaceae family and restored HFD-induced enteric dysbiosis at both compositional and functional levels.

Conclusion

Our findings suggest that Fuc might be a novel strategy to treat HFD-induced obesity and fatty liver.

Drug pharmacomicrobiomics and toxicomicrobiomics: from scattered reports to systematic studies of drug-microbiome interactions

INTRODUCTION

Pharmacomicrobiomics and toxicomicrobiomics study how variations within the human microbiome (the combination of human-associated microbial communities and their genomes) affect drug disposition, action, and toxicity. These emerging fields, interconnecting microbiology, bioinformatics, systems pharmacology, and toxicology, complement pharmacogenomics and toxicogenomics, expanding the scope of precision medicine. Areas covered: This article reviews some of the most recently reported pharmacomicrobiomic and toxicomicrobiomic interactions. Examples include the impact of the human gut microbiota on cardiovascular drugs, natural products, and chemotherapeutic agents, including immune checkpoint inhibitors. Although the gut microbiota has been the most extensively studied, some key drug-microbiome interactions involve vaginal, intratumoral, and environmental bacteria, and are briefly discussed here. Additionally, computational resources, moving the field from cataloging to predicting interactions, are introduced. Expert opinion: The rapid pace of discovery triggered by the Human Microbiome Project is moving pharmacomicrobiomic research from scattered observations to systematic studies focusing on screening microbiome variants against different drug classes. Better representation of all human populations will improve such studies by avoiding sampling bias, and the integration of multiomic studies with designed experiments will allow establishing causation. In the near future, pharmacomicrobiomic testing is expected to be a key step in screening novel drugs and designing precision therapeutics.