The gut microbiota-bile acid axis in cholestatic liver disease.

Cholestatic liver diseases (CLD) are characterized by impaired normal bile flow, culminating in excessive accumulation of toxic bile acids. The majority of patients with CLD ultimately progress to liver cirrhosis and hepatic failure, necessitating liver transplantation due to the lack of effective treatment. Recent investigations have underscored the pivotal role of the gut microbiota-bile acid axis in the progression of hepatic fibrosis via various pathways. The obstruction of bile drainage can induce gut microbiota dysbiosis and disrupt the intestinal mucosal barrier, leading to bacteria translocation. The microbial translocation activates the immune response and promotes liver fibrosis progression. The identification of therapeutic targets for modulating the gut microbiota-bile acid axis represents a promising strategy to ameliorate or perhaps reverse liver fibrosis in CLD. This review focuses on the mechanisms in the gut microbiota-bile acids axis in CLD and highlights potential therapeutic targets, aiming to lay a foundation for innovative treatment approaches.

Microbiota and Gut-Liver Axis: An Unbreakable Bond?

The gut microbiota, amounting to approximately 100 trillion (1014) microbes represents a genetic repertoire that is bigger than the human genome itself. Evidence on bidirectional interplay between human and microbial genes is mounting. Microbiota probably play vital roles in diverse aspects of normal human metabolism, such as digestion, immune modulation, and gut endocrine function, as well as in the genesis and progression of many human diseases. Indeed, the gut microbiota has been most closely linked to various chronic ailments affecting the liver, although concrete scientific data are sparse. In this narrative review, we initially discuss the basic epidemiology of gut microbiota and the factors influencing their initial formation in the gut. Subsequently, we delve into the gut-liver axis and the evidence regarding the link between gut microbiota and the genesis or progression of various liver diseases. Finally, we summarise the recent research on plausible ways to modulate the gut microbiota to alter the natural history of liver disease.

A microbial-derived succinylated bile acid to safeguard liver health.

In this issue of Cell, Nie and co-authors report that the microbe-derived bile acid (BA) 3-succinylated cholic acid protects against the progression of metabolic dysfunction-associated liver disease. Intriguingly, its protective mechanism does not involve traditional BA signaling pathways but is instead linked to the proliferation of the commensal microbe Akkermansia muciniphila.

Polygonatum kingianum Polysaccharides Enhance the Preventive Efficacy of Heat-Inactivated Limosilactobacillus reuteri WX-94 against High-Fat-High-Sucrose-Induced Liver Injury and Gut Dysbacteriosis.

Limosilactobacillus reuteri (L. reuteri) is an efficacious probiotic that could reduce inflammation and prevent metabolic disorders. Here, we innovatively found that Polygonatum kingianum polysaccharides (PKP) promoted proliferation and increased stability of L. reuteri WX-94 (a probiotic strain showing anti-inflammation potentials) in simulated digestive fluids in vitro. PKP was composed of galactose, glucose, mannose, and arabinose. The cell-free supernatant extracted from L. reuteri cultured with PKP increased ABTS•+, DPPH•, and FRAP scavenging capacities compared with the supernatant of the medium without PKP and increased metabolites with health-promoting activities, e.g., 3-phenyllactic acid, indole-3-lactic acid, indole-3-carbinol, and propionic acid. Moreover, PKP enhanced alleviating effects of heat-inactivated L. reuteri on high-fat-high-sucrose-induced liver injury in rats via reducing inflammation and regulating expressions of protein and genes involved in fatty acid metabolism (such as HIF1-α, FAßO, CPT1, and AMPK) and fatty acid profiles in liver. Such benefits correlated with its prominent effects on enriching Lactobacillus and short-chain fatty acids while reducing Dubosiella, Fusicatenilacter, Helicobacter, and Oscillospira. Our work provides novel insights into the probiotic property of PKP and emphasizes the great potential of the inactivated L. reuteri cultured with PKP in contracting unhealthy diet-induced liver dysfunctions and gut dysbacteriosis.

A rare case report of liver masses caused by Actinomyces species.

Actinomycosis is a rare infection caused by Actinomyces spp. Of all actinomycosis infections, only 5% of Hepatic Actinomycosis (HA) infection has been reported. This disease is often misdiagnosed as a malignancy. This case report presents a 45-year-old woman with diabetes, initially suspected of intrahepatic cholangiocarcinoma, but after careful tissue staining, we found the results supported HA infection.

Respiratory tract viral infections associated sepsis in patients with underlying liver disease: Viral sepsis an entity to look forward!

BACKGROUND: Sepsis remains a global health burden associated with significant morbidity and mortality. Bacteria are known to be the predominant pathogens in sepsis; however, viral etiologies in sepsis are still under diagnosed. Respiratory viral pathogens have been previously linked to sepsis, but the knowledge of incidence, disease burden and mortality of viral-induced sepsis remains limited. This study aimed at understanding the role of respiratory viral infections in the causation of sepsis in liver disease patients. METHODS: In this retrospective study, the clinical records of liver disease patients with influenza-like illness, whose requests for respiratory viral testing were received from January 2019 to December 2022, were reviewed. Respiratory viruses were identified using FilmArray 2.0 respiratory panel (BioFire Diagnostics, Utah, USA). RESULTS: Of 1391 patients tested, a respiratory viral etiology was detected in 23%. The occurrence of sepsis was seen in 35%. Among these, isolated viral etiology with no other bacterial/fungal coinfection was found in 55% of patients. Rhinovirus/Enterovirus was found as the most common underlying viral etiology (23.4%). The sepsis prevalence was higher among patients with associated comorbidities (45%) and decompensated cirrhosis (84%). On multi-variable analysis, no factor was found independently associated with sepsis-related mortality. CONCLUSION: This study underlines the importance of isolated viral etiology in causation of sepsis among liver disease patients. Patients with comorbidities, older age and decompensated cirrhosis are at an increased risk of developing sepsis and are associated with poorer outcomes. Accurate and timely identification of the viral etiology in sepsis would prevent the misuse of antibiotics and improve overall patient care.

Alterations in the fecal microbiota in patients with advanced cystic fibrosis liver disease after 6 months of elexacaftor/tezacaftor/ivacaftor.

BACKGROUND: Cystic fibrosis associated liver disease (CFLD) carries a significant disease burden with no effective preventive therapies. According to the gut-liver axis hypothesis for CFLD pathogenesis, dysbiosis and increased intestinal inflammation and permeability permit pathogenic bacterial translocation into the portal circulation, leading to hepatic inflammation and fibrosis. Evaluating the effect of CFTR (cystic fibrosis transmembrane conductance regulator) modulation with elexacaftor/tezacaftor/ivacaftor (ETI) may help determine the role of CFTR in CFLD and increase understanding of CFLD pathogenesis, which is critical for developing therapies. We aimed to characterize the fecal microbiota in participants with CF with and without advanced CFLD (aCFLD) before and after ETI. METHODS: This is an ancillary analysis of stool samples from participants ages ≥12 y/o enrolled in PROMISE (NCT04038047). Included participants had aCFLD (cirrhosis with or without portal hypertension, or non-cirrhotic portal hypertension) or CF without liver disease (CFnoLD). Fecal microbiota were defined by shotgun metagenomic sequencing at baseline and 1 and 6 months post-ETI. RESULTS: We analyzed 93 samples from 34 participants (11 aCFLD and 23 CFnoLD). Compared to CFnoLD, aCFLD had significantly higher baseline relative abundances of potential pathogens Streptococcus salivarius and Veillonella parvula. Four of 11 aCFLD participants had an initially abnormal fecal calprotectin that normalized 6 months post-ETI, correlating with a significant decrease in S. salivarius and a trend towards decreasing V. parvula. CONCLUSIONS: These results support an association between dysbiosis and intestinal inflammation in CFLD with improvements in both post-ETI, lending further support to the gut-liver axis in aCFLD.

Longitudinal gut fungal alterations and potential fungal biomarkers for the progression of primary liver disease.

Liver disease, a major health concern worldwide, is a serious and progressive disorder. Herein, we not only established a mouse model of DEN+CCl4-induced primary liver disease but also collected clinical human samples to investigate longitudinal alterations in the gut mycobiome. As liver disease advanced, gut integrity was disrupted, and the mycobiota was disturbed in the mouse models. The metabolites associated with hepatocellular carcinoma (HCC) differed from those associated with the cirrhotic phase as follows: levels of stercobilin and aflatoxin B1 dialcohol were reduced, while levels of triterpenoids, bafilomycin A1, and DHEA were increased in the HCC group. The abundance of the phylum Chytridiomycota increased as the chronic liver disease progressed and was then replaced by the phylum Ascomycota in HCC. Based on the results from clinical human samples, the genus Candida (Ascomycota) (in humans) and the genus Kazachstania (Ascomycota) (in mice) occupied a dominant position in the HCC group, while other fungi were depleted. The increased abundance of C. albicans and depletion of S. cerevisiae may be hallmarks of the progression of liver cirrhosis to early HCC. Moreover, the administration of C. albicans and S. cerevisiae in the LC-HCC progression could accelerate or retard the progression of HCC. Therefore, gut fungi have the potential to serve as a noninvasive clinical biomarker and even a treatment method.

First Report of Campylobacter hepaticus Isolation in Laying Hens and Broiler Breeders with Spotty Liver Disease in Costa Rica.

Poultry producers in Costa Rica have informally reported a spotty liver disease-like syndrome for more than 20 yr. However, despite many attempts, the infectious agent responsible for this syndrome had not been identified. Therefore, following current knowledge of spotty liver disease diagnosis, we invited veterinarians and poultry producers to submit samples to the diagnostic laboratories of the Veterinary Medicine School, Universidad Nacional, to identify the infectious agent of this syndrome. Veterinarians and poultry producers were instructed to collect gallbladders and livers aseptically and send them for pathology examinations and bacterial cultures in less than 24 hr after collection. Samples were processed for standard histopathologic studies and cultured under aerophilic, anaerobic, and microaerophilic conditions. Campylobacter-like colonies were isolated and identified by biochemical and PCR tests. Here we report for the first time the isolation, biochemical characterization, and molecular confirmation of Campylobacter hepaticus in laying hens and broiler breeders with spotty liver disease in Costa Rica.

Nota de investigación- Primer reporte de aislamiento de Campylobacter hepaticus en gallinas de postura y reproductoras pesadas con necrosis hepática focal en Costa Rica. Los productores avícolas en Costa Rica han reportado extraoficialmente un síndrome similar a la necrosis hepática focal durante más de 20 años. Sin embargo, a pesar de muchos intentos, el agente infeccioso responsable de este síndrome no había sido identificado. Por ello, siguiendo los conocimientos actuales relacionados con la necrosis hepática focal, se invitó a los veterinarios y a los productores avícolas a enviar muestras a los laboratorios de diagnóstico de la Facultad de Medicina Veterinaria de la Universidad Nacional, para identificar el agente infeccioso de este síndrome. Se instruyó a los veterinarios y productores avícolas para recolectar vesículas biliares e hígados asépticamente y enviarlos para exámenes patológicos y para cultivos bacterianos en menos de 24 horas después de la recolección. Las muestras se procesaron para estudios histopatológicos estándar y se cultivaron en condiciones aerófilas, anaeróbicas y microaerófilas. Las colonias sugestivas de Campylobacter se aislaron e identificaron mediante pruebas bioquímicas y por PCR. Aquí se reporta por primera vez el aislamiento, caracterización bioquímica y confirmación molecular de Campylobacter hepaticus en gallinas de postura y reproductoras pesadas con la necrosis hepática focal en Costa Rica.

Campylobacter hepaticus in the Production Environment and Stagnant Water as a Potential Source of C. hepaticus Causing Spotty Liver Disease in Free-Range Laying Hens in Georgia, United States.

Spotty liver disease (SLD) has emerged as an important cause of disease in egg-producing flocks in countries such as the United Kingdom and Australia and has emerged in the United States. The organisms implicated in SLD include Campylobacter hepaticus and, more recently, Campylobacter bilis. These organisms have been found to cause focal lesions on the livers of infected birds. Campylobacter hepaticus infection results in reduced egg production, decreased feed consumption resulting in reduced egg size, and increased mortality of highly valuable hens. In the fall of 2021, birds from two flocks (A and B) of organic pasture-raised laying hens were submitted to the Poultry Diagnostic Research Center at the University of Georgia with a history suspicious of SLD. Postmortem examination of Flock A found 5/6 hens had small multifocal lesions on the liver and were PCR positive for C. hepaticus from pooled swab analysis of samples of the liver and gall bladder. Necropsy of Flock B found 6/7 submitted birds had spotty liver lesions. In pooled bile swabs, 2/7 hens from Flock B were also PCR positive for C. hepaticus. A follow-up visit to Flock A was scheduled 5 days later, as well as a visit to a flock where SLD has not been reported (Flock C), which was used as a comparative control. Samples of the liver, spleen, cecal tonsil, ceca, blood, and gall bladder were collected from six hens per house. Additionally, feed, water nipples, and environmental water (stagnant water outside the house) were collected from the affected farm and the control farm. To detect the organism, all samples collected were subjected to direct plating on blood agar and enrichment in Preston broth with incubation under microaerophilic conditions. After multiple phases of bacterial culture purification from all samples, single bacterial cultures displaying characteristics of C. hepaticus were tested by PCR to confirm identity. From Flock A, liver, ceca, cecal tonsils, gall bladder, and environmental water were PCR positive for C. hepaticus. No positive samples were detected in Flock C. After another follow-up visit, 10 wk later, Flock A was PCR positive for C. hepaticus from gall bladder bile and feces and one environmental water sample displayed a weak positive reaction for C. hepaticus. Flock C was PCR negative for C. hepaticus. To gain more knowledge about C. hepaticus prevalence, a survey of 6 layer hens from 12 different layer hen flocks between the ages of 7 to 80 wk, raised in different housing systems, were tested for C. hepaticus. The 12 layer hen flocks were culture and PCR negative for C. hepaticus. Currently, there are no approved treatments for C. hepaticus and no vaccine is available. The results of this study suggest that C. hepaticus may be endemic in some areas of the United States, and free-range laying hens may be exposed from the environment/stagnant water in areas where they range.

Campylobacter hepaticus en el ambiente de producción avícola y en el agua estancada como fuente potencial de C. hepaticus que causante de la necrosis hepática focal en gallinas ponedoras de corral en Georgia, Estados Unidos. La necrosis hepática focal (SLD, por sus siglas en inglés) se ha convertido en una causa importante de enfermedad en las parvadas productoras de huevo en países como el Reino Unido y Australia y también ha surgido en los Estados Unidos. Los organismos implicados en necrosis hepática focal incluyen Campylobacter hepaticus y, más recientemente, Campylobacter bilis. Se ha encontrado que estos organismos causan lesiones focales en el hígado de las aves infectadas. La infección por C. hepaticus da como resultado una reducción en la producción de huevos, una disminución en el consumo de alimento, lo que resulta en una reducción del tamaño de los huevos y una mayor mortalidad de gallinas de alto valor económico. En el otoño del 2021, aves de dos lotes (A y B) de gallinas de postura criadas en pastos orgánicos se enviaron al Centro de Diagnóstico e Investigación Avícolas de la Universidad de Georgia con antecedentes sospechosos de necrosis hepática focal. En el examen post mortem de la parvada A se encontró que cinco de un total de seis gallinas tenían pequeñas lesiones multifocales en el hígado y fueron positivas mediante PCR para C. hepaticus a partir de un análisis de hisopos combinados de muestras del hígado y de la vesícula biliar. La necropsia de la parvada B encontró que seis de un total de siete aves enviadas tenían lesiones hepáticas irregulares. En muestras agrupadas de bilis, dos de un total de siete gallinas de la parvada B también fueron positivas a C. hepaticus por PCR. Se programó una visita de seguimiento a la Parvada A cinco días después, así como una visita a una parvada en la que no se había reportado la presencia de necrosis hepática focal (Parvada C), que se utilizó como control para propósitos de comparación. Se recolectaron muestras de hígado, bazo, tonsilas cecales, sacos ciegos, sangre y vesícula biliar de seis gallinas por gallinero. Además, se recolectó alimento, muestras de agua de bebederos de niple y agua ambiental (agua estancada fuera de la casa) de la granja afectada y la granja de control. Para detectar el organismo, todas las muestras recolectadas se sometieron a siembra directa en agar sangre y enriquecimiento en caldo Preston con incubación en condiciones microaerófilas. Después de varias fases de purificación del cultivo bacteriano de todas las muestras, se analizaron mediante PCR los cultivos bacterianos individuales que mostraban características de C. hepaticus para confirmar la identidad. De la parvada A, el hígado, el ciego, las tonsilas cecales, la vesícula biliar y el agua ambiental dieron positivo por PCR para C. hepaticus. No se detectaron muestras positivas en la parvada C. Después una segunda visita de seguimiento, 10 semanas después, la parvada A mostró resultado positivo por PCR para C. hepaticus en la bilis de la vesícula biliar y en las heces, y una muestra de agua ambiental mostró una reacción positiva débil para C. hepaticus . La parvada C resultó negativa mediante PCR para C. hepaticus. Para obtener más conocimiento sobre la prevalencia de C. hepaticus, se realizó un muestreo incluyendo seis gallinas de postura de 12 lotes diferentes de gallinas ponedoras entre las edades de 7 a 80 semanas, criadas en diferentes sistemas de alojamiento, para detectar C. hepaticus. Las doce parvadas de gallinas de postura fueron negativas por cultivo y mediante PCR para C. hepaticus. Actualmente, no hay tratamientos aprobados para C. hepaticus y no hay vacuna disponible. Los resultados de este estudio sugieren que C. hepaticus puede ser endémico en algunas áreas de los Estados Unidos, y las gallinas de postura bajo pastoreo pueden estar expuestas al medio ambiente o al agua estancada en las áreas donde están alojadas.

Characterisation of N-linked protein glycosylation in the bacterial pathogen Campylobacter hepaticus.

Campylobacter hepaticus is an important pathogen which causes Spotty Liver Disease (SLD) in layer chickens. SLD results in an increase in mortality and a significant decrease in egg production and therefore is an important economic concern of the global poultry industry. The human pathogen Campylobacter jejuni encodes an N-linked glycosylation system that plays fundamental roles in host colonization and pathogenicity. While N-linked glycosylation has been extensively studied in C. jejuni and is now known to occur in a range of Campylobacter species, little is known about C. hepaticus glycosylation. In this study glycoproteomic analysis was used to confirm the functionality of the C. hepaticus N-glycosylation system. It was shown that C. hepaticus HV10T modifies > 35 proteins with an N-linked heptasaccharide glycan. C. hepaticus shares highly conserved glycoproteins with C. jejuni that are involved in host colonisation and also possesses unique glycoproteins which may contribute to its ability to survive in challenging host environments. C. hepaticus N-glycosylation may function as an important virulence factor, providing an opportunity to investigate and develop a better understanding the system's role in poultry infection.

Campylobacter bilis, the second novel Campylobacter species isolated from chickens with Spotty Liver Disease, can cause the disease.

Spotty Liver Disease (SLD) is a significant disease of commercial layer hens. It can cause up to 10 % flock mortalities and reduce egg production by 25 %. Campylobacter hepaticus has been identified as the main cause of the disease, although it also appears that predisposing factors, such as some form of stress, may increase the likelihood of clinical disease occurring. Recently, a newly identified species, Campylobacter bilis, was isolated from bile samples of clinical SLD affected chickens. To investigate the pathogenic potential of C. bilis two independent isolates were used in infection trials of layer hens. Within 6 days of oral challenge birds developed typical SLD liver lesions, demonstrating that both strains induced SLD. C. bilis could be recovered from all the challenged birds that developed SLD. Thus, each of the steps in Koch's postulates have been fulfilled, confirming that C. bilis is an additional cause of SLD. A PCR method was developed which can specifically detect C. bilis from samples with complex microbiota. The identification of this newly discovered Campylobacter species as a second cause of SLD and the provision of a rapid method to detect the SLD causing bacterium will help with SLD vaccine development and epidemiology, thus assisting in the control of this important disease of poultry.

Hepatic Cyst Infection Following Recurrent Biliary Obstruction in Polycystic Liver Disease.

An 89-year-old man with polycystic liver disease (PCLD) received uncovered self-expandable metallic stent (SEMS) placement above the papilla for malignant biliary obstruction caused by cholangiocarcinoma. He developed cholangitis ten months later due to SEMS occlusion caused by tumor ingrowth, and 2 plastic biliary stents were placed inside the SEMS across the papilla. Fever and right costal pain appeared two weeks after reintervention. Suspecting hepatic cyst infection based on imaging studies, percutaneous transhepatic cyst drainage was performed. Increased inflammatory cells and the presence of pathogens in the cyst fluid led to a definitive diagnosis of hepatic cyst infection. Following drainage, the hepatic cyst shrank with resolution of the symptoms. SEMS occlusive-related cholangitis or retrograde infection due to duodenal-biliary reflux after reintervention was considered as the cause of the hepatic cyst infection. Careful clinical and imaging evaluation should be performed in patients with PCLD undergone biliary stenting, because cyst infection may occur following stent occlusion or subsequent biliary reintervention.

Phytogen Improves Performance during Spotty Liver Disease by Impeding Bacterial Metabolism and Pathogenicity.

A range of antibiotic alternative products is increasingly studied and manufactured in the current animal agriculture, particularly in the poultry industry. Phytogenic feed additives are known for their remarkable ability to suppress pathogens such as Clostridium spp., Escherichia coli, and Salmonella. Other than enhancing biosecurity, improvements in productivity and performance were also observed. However, clear mechanisms for these improvements were not established. In this study, 20,000 Lohman-Brown layers were provided with phytogenic supplement from 16 to 40 weeks of age, and performance parameters were assessed against the same number of unsupplemented control birds. The performance results showed that the birds with phytogenic supplementation presented consistently reduced mortality, increased rate of lay, and increased average egg weight. Functional analysis through shotgun sequencing of cecal metagenomes confirmed a substantial functional shift in the microbial community, showing that phytogen significantly reduced the range of microbial functions, including the production of essential vitamins, cofactors, energy, and amino acids. Functional data showed that phytogen supplementation induced a phenotypic shift in intestinal bacteria LPS phenotype toward the less pathogenic form. The study corroborates the use of phytogenic products in antibiotic-free poultry production systems. The productivity improvements in the number and weight of eggs produced during Spotty Liver Disease justify further optimizing phytogenic alternatives for use in high-risk open and free-range poultry systems. IMPORTANCE The present study establishes the beneficial effects of the continuous phytogenic supplementation reflected in reduced diarrhea and mortality and higher egg productivity under normal conditions and during a natural outbreak of Spotty Liver Disease. Our data points to the importance of phytogen-driven alteration of microbial pathogenicity and fitness-related functional capabilities revealed on the commercial layer farm. Phytogenic product showed an ability to improve the bird's welfare and sustainability in free-range poultry production systems.

Epigallocatechin-3-gallate ameliorates liver injury secondary to Pseudomonas aeruginosa pneumonia.

Pseudomonas aeruginosa is a dangerous pathogen causing nosocomial pneumonia. P. aeruginosa infection-induced liver damage is another fatal threat, and antibiotic treatment is not effective in relieving P. aeruginosa virulence-triggered damage. We here evaluated the protective effect of epigallocatechin gallate (EGCG), a substance that inhibits virulence of P. aeruginosa through quorum quenching, on liver damage secondary to P. aeruginosa infection. Mice were pretreated with EGCG (20, 40, and 80 mg/kg) for 3 days, and then infected with P. aeruginosa through intratracheal instillation to model acute pneumonia. The mice were sacrificed after 24 h of infection, and samples were harvested for subsequent analysis. EGCG significantly decreased the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histopathological changes of liver were significantly ameliorated by EGCG. It also significantly reduced oxidative stress that induced liver damage in P. aeruginosa infection, which relied not on the activation of the Nrf2-HO-1 pathway but on the upregulation of the activity of antioxidative enzymes. Then, the inflammatory response in the liver was tested. EGCG inhibited the release of pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6) by blocking the inflammation regulating signaling of the TLR4-myD88-NF-κB pathway. EGCG upregulated the activation of nuclear receptors to stronger the liver protective activity against P. aeruginosa infection. Conclusively, EGCG exhibited a significant hepatoprotective effective against P. aeruginosa infection.

Modulation of Gut Microbiota by Magnesium Isoglycyrrhizinate Mediates Enhancement of Intestinal Barrier Function and Amelioration of Methotrexate-Induced Liver Injury.

Background: The gut-liver axis plays a crucial role in various liver diseases. Therefore, targeting this crosstalk may provide a new treatment strategy for liver diseases. However, the exact mechanism underlying this crosstalk and its impact on drug-induced liver injury (DILI) requires clarification. Aim: This study aimed to investigate the potential mechanism and therapeutic effect of MgIG on MTX-induced liver injury, which is associated with the gut-liver axis and gut microbiota. Methods: An MTX-induced liver injury model was generated after 20-mg/kg/3d MTX application for 30 days. Meanwhile, the treatment group was treated with 40-mg/kg MgIG daily. Histological examination, aminotransferase, and aspartate aminotransferase enzyme levels were estimated to evaluate liver function. Immune cells infiltration and inflammatory cytokines were detected to indicate inflammation levels. Colon histological score, intestinal barrier leakage, and expression of tight junctions were employed to assess the intestinal injury. Bacterial translocation was observed using fluorescent in situ hybridisation, colony-forming unit counting, and lipopolysaccharide detection. Alterations in gut microbial composition were analysed using 16s rDNA sequencing and relative quantitative polymerase chain reaction. Short-chain-fatty-acids and lactic acid concentrations were then utilized to validate changes in metabolites of specific bacteria. Lactobacillus sp. supplement and fecal microbiota transplantation were used to evaluate gut microbiota contribution. Results: MTX-induced intestinal and liver injuries were significantly alleviated using MgIG treatment. Bacterial translocation resulting from the intestinal barrier disruption was considered a crucial cause of MTX-induced liver injury and the therapeutic target of MgIG. Moreover, MgIG was speculated to have changed the gut microbial composition by up-regulating probiotic Lactobacillus and down-regulating Muribaculaceae, thereby remodelling the intestinal barrier and inhibiting bacterial translocation. Conclusion: The MTX-induced intestinal barrier was protected owing to MgIG administration, which reshaped the gut microbial composition and inhibited bacterial translocation into the liver, thus attenuating MTX-related DILI.

Gut Microbiota Targeted Approach in the Management of Chronic Liver Diseases.

The liver is directly connected to the intestines through the portal vein, which enables the gut microbiota and gut-derived products to influence liver health. There is accumulating evidence of decreased gut flora diversity and alcohol sensitivity in patients with various chronic liver diseases, including non-alcoholic/alcoholic liver disease, chronic hepatitis virus infection, primary sclerosing cholangitis and liver cirrhosis. Increased intestinal mucosal permeability and decline in barrier function were also found in these patients. Followed by bacteria translocation and endotoxin uptake, these will lead to systemic inflammation. Specific microbiota and microbiota-derived metabolites are altered in various chronic liver diseases studies, but the complex interaction between the gut microbiota and liver is missing. This review article discussed the bidirectional relationship between the gut and the liver, and explained the mechanisms of how the gut microbiota ecosystem alteration affects the pathogenesis of chronic liver diseases. We presented gut-microbiota targeted interventions that could be the new promising method to manage chronic liver diseases.

Systemic Bacterial Infection in a Captive Agouti (Dasyprocta leporina Linnaeus, 1758).

The agouti (Dasyprocta leporina) is a neotropical rodent which has the potential to be domesticated. As such, some research studies have been done on the biology of this animal. Recently, these animals are being kept in captivity as a source of animal protein. Animals which are kept in captivity may present diseases that would not have been reported in the wild due to lack of observation or the lack of occurrence. The aim of this short communication is to report a case of systemic bacterial infection that affected the lungs and liver of a captive agouti. Bacterial analysis revealed that the infection was caused by Escherichia coli. Bacterial infections have been reported in the mammary tissue as well as the skin of the agouti, but to the authors' knowledge, this is the first report of systemic infection in the agouti affecting several organs. This case was seen in a nine-month-old male agouti that was being housed at the University of the West Indies Field Station (UWI, UFS). The animal showed no apparent sign of disease except for lethargy and subsequently died before any treatment was administered. These findings showed that the agouti may have been under some stress (nutritional or environmental) which predisposed this animal to this infection. Future work has to address the nutritional requirements for the growing agouti as well as some treatment options for managements of similar cases in the future.