Association of Gut Microbiota and Metabolites With Disease Progression in Children With Biliary Atresia

Indole 3-acetate and response to therapy in borderline resectable or locally advanced pancreatic cancer

Background/Aims

It was recently reported that a higher concentration of the bacterially produced metabolite indole 3-acetate (3-IAA) in blood was linked to a better response to chemotherapy in patients with metastatic pancreatic ductal adenocarcinoma (PDAC). Here, we aimed to extend these observations to patients diagnosed with non-metastatic PDAC.

Method

We measured circulating 3-IAA in samples from a prospective population-based cohort of 124 patients with borderline resectable or locally advanced PDAC, collected before initiating neoadjuvant chemotherapy. The majority (61%) of the patients were treated with FOLFIRINOX. We used univariable and multivariable Cox proportional hazards regression to estimate the association between pre-treatment 3-IAA and overall survival.

Results

The median serum 3-IAA concentration before chemotherapy was 290 (interquartile range 203-417) ng/mL. The unadjusted hazard ratio (HR) for pre-treatment log2(3-IAA) was 0.93, 95% confidence interval (CI) [0.74-1.16], p=0.52. When adjusting for age, ECOG, CA19-9 and tumor classification, the HR for log2(3-IAA) was 0.87, 95% CI [0.68-1.12], p=0.28.

Conclusion

Our findings suggest that the potentiating effect of 3-IAA observed in metastatic PDAC undergoing chemotherapy may not translate to borderline resectable or locally advanced PDAC. We recommend additional clinical validation of 3-IAA's predictive value in different categories of PDAC before implementation attempts in human studies are initiated.

Association of gut microbiota and gut metabolites and adverse outcomes in biliary atresia: A longitudinal prospective study

BACKGROUND

The Kasai portoenterostomy (KPE) aims to re-establish bile flow in biliary atresia (BA); however, BA remains the commonest indication for liver transplantation in pediatrics. Gut microbiota-host interplay is increasingly associated with outcomes in chronic liver disease. This study characterized fecal microbiota and fatty acid metabolites in BA.

METHODS

Fecal samples were prospectively collected in newly diagnosed BA infants (n = 55) before and after KPE. Age-matched healthy control (n = 19) and cholestatic control (n = 21) fecal samples were collected. Fecal 16S rRNA gene amplicon sequencing for gut microbiota and gas chromatography for fecal fatty acids was performed.

RESULTS

Increased abundance of Enterococcus in pre-KPE BA and cholestatic control infants, compared to healthy infants, was demonstrated. At the early post-KPE time points, increased alpha diversity was revealed in BA versus healthy cohorts. A lower relative abundance of Bifidobacterium and increased Enterococcus, Clostridium, Fusobacterium, and Pseudomonas was seen in infants with BA. Fecal acetate was reduced, and fecal butyrate and propionate were elevated in early post-KPE BA infants. Higher post-KPE alpha diversity was associated with nonfavorable clinical outcomes (6-month jaundice and liver transplantation). A higher relative abundance of post-KPE Streptococcus and Fusobacterium and a lower relative abundance of Dorea, Blautia, and Oscillospira were associated with nonfavorable clinical outcomes. Blautia inversely correlated to liver disease severity, and Bifidobacterium inversely correlated to fibrosis biomarkers. Bifidobacterium abundance was significantly lower in infants experiencing cholangitis within 6 months after KPE.

CONCLUSIONS

Increased diversity, enrichment of pathogenic, and depletion of beneficial microbiota early post-KPE are all factors associated with nonfavorable BA outcomes. Manipulation of gut microbiota in the early postsurgical period could provide therapeutic potential.

Gut microbiota: a crucial player in the combat against tuberculosis

The mammalian gastrointestinal tract quickly becomes densely populated with foreign microorganisms shortly after birth, thereby establishing a lifelong presence of a microbial community. These commensal gut microbiota serve various functions, such as providing nutrients, processing ingested compounds, maintaining gut homeostasis, and shaping the intestinal structure in the host. Dysbiosis, which is characterized by an imbalance in the microbial community, is closely linked to numerous human ailments and has recently emerged as a key factor in health prognosis. Tuberculosis (TB), a highly contagious and potentially fatal disease, presents a pressing need for improved methods of prevention, diagnosis, and treatment strategies. Thus, we aim to explore the latest developments on how the host's immune defenses, inflammatory responses, metabolic pathways, and nutritional status collectively impact the host's susceptibility to or resilience against Mycobacterium tuberculosis infection. The review addresses how the fluctuations in the gut microbiota not only affect the equilibrium of these physiological processes but also indirectly influence the host's capacity to resist M. tuberculosis. This work highlights the central role of the gut microbiota in the host-microbe interactions and provides novel insights for the advancement of preventative and therapeutic approaches against tuberculosis.

Biliary fibrosis is an important but neglected pathological feature in hepatobiliary disorders: from molecular mechanisms to clinical implications

Fibrosis resulting from pathological repair secondary to recurrent or persistent tissue damage often leads to organ failure and mortality. Biliary fibrosis is a crucial but easily neglected pathological feature in hepatobiliary disorders, which may promote the development and progression of benign and malignant biliary diseases through pathological healing mechanisms secondary to biliary tract injuries. Elucidating the etiology and pathogenesis of biliary fibrosis is beneficial to the prevention and treatment of biliary diseases. In this review, we emphasized the importance of biliary fibrosis in cholangiopathies and summarized the clinical manifestations, epidemiology, and aberrant cellular composition involving the biliary ductules, cholangiocytes, immune system, fibroblasts, and the microbiome. We also focused on pivotal signaling pathways and offered insights into ongoing clinical trials and proposing a strategic approach for managing biliary fibrosis-related cholangiopathies. This review will offer a comprehensive perspective on biliary fibrosis and provide an important reference for future mechanism research and innovative therapy to prevent or reverse fibrosis.

Biliary atresia: the role of gut microbiome, and microbial metabolites

Biliary atresia (BA) is a progressive fibroinflammatory disease affecting both the extrahepatic and intrahepatic bile ducts, potentially leading to chronic cholestasis and biliary cirrhosis. Despite its prevalence, the exact mechanisms behind BA development remain incompletely understood. Recent research suggests that the gut microbiota and its metabolites may play significant roles in BA development. This paper offers a comprehensive review of the changing characteristics of gut microbiota and their metabolites at different stages of BA in children. It discusses their influence on the host's inflammatory response, immune system, and bile acid metabolism. The review also explores the potential of gut microbiota and metabolites as a therapeutic target for BA, with interventions like butyrate and gut microbiota preparations showing promise in alleviating BA symptoms. While progress has been made, further research is necessary to untangle the complex interactions between gut microbiota and BA, paving the way for more effective prevention and treatment strategies for this challenging condition.

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.

Gut Bifidobacterium longum is associated with better native liver survival in patients with biliary atresia

Background & Aims

The gut microbiome plays an important role in liver diseases, but its specific impact on biliary atresia (BA) remains to be explored. We aimed to investigate the microbial signature in the early life of patients with BA and to analyze its influence on long-term outcomes.

Methods

Fecal samples (n = 42) were collected from infants with BA before and after Kasai portoenterostomy (KPE). The stool microbiota was analyzed using 16S rRNA next-generation sequencing and compared with that of age-matched healthy controls (HCs). Shotgun metagenomic sequencing analysis was employed to confirm the bacterial composition in 10 fecal samples before KPE. The correlation of the microbiome signature with liver function and long-term outcomes was assessed.

Results

In the 16S rRNA next-generation sequencing analysis of fecal microbiota, the alpha and beta diversity analyses revealed significant differences between HCs and patients with BA before and after KPE. The difference in microbial composition analyzed by linear discriminant analysis and random forest classification revealed that the abundance of Bifidobacterium longum (B. longum) was significantly lower in patients before and after KPE than in HCs. The abundance of B. longum was negatively correlated with the gamma-glutamyltransferase level after KPE (p <0.05). Patients with early detectable B. longum had significantly lower total and direct bilirubin 3 months after KPE (p <0.005) and had a significantly lower liver transplantation rate (hazard ratio: 0.16, 95% CI 0.03-0.83, p = 0.029). Shotgun metagenomic sequencing also revealed that patients with BA and detectable B. longum had reduced total and direct bilirubin after KPE.

Conclusion

The gut microbiome of patients with BA differed from that of HCs, with a notable abundance of B. longum in early infancy correlating with better long-term outcomes.

Impact and implications

Bifidobacterium longum (B. longum) is a beneficial bacterium commonly found in the human gut. It has been studied for its potential impacts on various health conditions. In patients with biliary atresia, we found that a greater abundance of B. longum in the fecal microbiome is associated with improved clinical outcomes. This suggests that early colonization and increasing B. longum levels in the gut could be a therapeutic strategy to improve the prognosis of patients with biliary atresia.

Analysis of gut microecological characteristics and differences between children with biliary atresia and non-biliary atresia in infantile cholestasis

Introduction

In infants with cholestasis, variations in the enterohepatic circulation of bile acids and the gut microbiota (GM) characteristics differ between those with biliary atresia (BA) and non-BA, prompting a differential analysis of their respective GM profiles.

Methods

Using 16S rDNA gene sequencing to analyse the variance in GM composition among three groups: infants with BA (BA group, n=26), non-BA cholestasis (IC group, n=37), and healthy infants (control group, n=50). Additionally, correlation analysis was conducted between GM and liver function-related indicators.

Results

Principal component analysis using Bray-Curtis distance measurement revealed a significant distinction between microbial samples in the IC group compared to the two other groups. IC-accumulated co-abundance groups exhibited positive correlations with aspartate aminotransferase, alanine aminotransferase, total bilirubin, direct bilirubin, and total bile acid serum levels. These correlations were notably reinforced upon the exclusion of microbial samples from children with BA.

Conclusion

The varying "enterohepatic circulation" status of bile acids in children with BA and non-BA cholestasis contributes to distinct GM structures and functions. This divergence underscores the potential for targeted GM interventions tailored to the specific aetiologies of cholestasis.

Diagnostic and prognostic value of the gut microbiota and its metabolite butyrate in children with biliary atresia

PURPOSE

To determine the prevalent microbiological profile of biliary atresia (BA) patients at the time of its occurrence by studying their intestinal flora.

METHODS

A total of 118 gut microbiota samples from three groups of 43 BA patients, 33 disease controls (DC) with other cholestatic diseases and 42 healthy controls (HC), were analyzed by deep mining of public data. Subsequently, a total of 23 fecal samples from three groups of clinically collected patients (11 BA, 6 DC and 6 HC) were sequenced for 16S rRNA gene amplification and analyzed for serum butyrate (BU) level by liquid chromatography.

RESULTS

Taxonomic analysis revealed significant differences in the composition of the intestinal microbiota between BA patients and controls, with a reduction in diversity and a higher abundance of Proteobacteria, Streptococcus and Lactobacillus in the BA group. Database and clinical data analyses concluded that Streptococcus/Bacteroides (AUC = 0.9035, 95% CI 0.8347-0.9722, P < 0.0001) or Streptococcus/Eggerthella (AUC = 0.8333, 95% CI 0.6340-1.000, P = 0.027) was the best microbiota to differentiate between BA and DC. Serum butyrate levels were low in the BA and DC groups and differed from the HC group (P = 0.01, P = 0.04). Butyrate levels in BA were negatively correlated with jaundice clearance and cholangitis, but not statistically significant.

CONCLUSIONS

Our study reveals changes in the composition of the gut microbiota in BA, especially the butyrate-producing microbiota, and suggests the potential for using gut microbiota as a noninvasive diagnostic benefit for BA. Low levels of serum butyrate in BA may indicate a poor prognosis.

Alterations in gut microbiota and metabolite profiles in patients with infantile cholestasis

BACKGROUND

Infantile cholestasis (IC) is the most common hepatobiliary disease in infants, resulting in elevated direct bilirubin levels. Indeed, hepatointestinal circulation impacts bile acid and bilirubin metabolism. This study evaluates changes in the gut microbiota composition in children with IC and identifies abnormal metabolite profiles associated with microbial alterations.

RESULTS

The gut microbiota in the IC group exhibits the higher abundance of Veillonella, Streptococcus and Clostridium spp. (P < 0.05), compared to healthy infants (CON) group. Moreover, the abundance of Ruminococcus, Vibrio butyricum, Eubacterium coprostanogenes group, Intestinibacter, and Faecalibacterium were lower (P < 0.05). In terms of microbiota-derived metabolites, the levels of fatty acids (palmitoleic, α-linolenic, arachidonic, and linoleic) (P < 0.05) increased and the levels of amino acids decreased in IC group. Furthermore, the abundances of Ruminococcus, Eubacterium coprostanoligenes group, Intestinibacter and Butyrivibrio are positively correlated with proline, asparagine and aspartic acid, but negatively correlated with the α-linolenic acid, linoleic acid, palmitoleic acid and arachidonic acid. For analysis of the relationship between the microbiota and clinical index, it was found that the abundance of Veillonella and Streptococcus was positively correlated with serum bile acid content (P < 0.05), while APTT, PT and INR were negatively correlated with Faecalibalum and Ruminococcus (P < 0.05).

CONCLUSION

Microbiota dysbiosis happened in IC children, which also can lead to the abnormal metabolism, thus obstructing the absorption of enteral nutrition and aggravating liver cell damage. Veillonella, Ruminococcus and Butyrivibrio may be important microbiome related with IC and need further research.

A novel gut microbiome-immune axis influencing pathology in HCMV infected infants with neonatal cholestasis

The interplay of active HCMV infection with gut dysbiosis in the immunopathology of cholestasis in neonates and infants remains unexplored. In this study, we evaluated gut microbiome profiles and immune dysfunction in a cohort of HCMV infected cholestatic infants (IgM positive, N = 21; IgM negative, N = 25) compared to healthy infants, N = 10. HCMV infected IgM positive individuals exhibited increased clinical severity in terms of liver dysfunction, altered CD4+: CD8+ ratio, and elevated Granzyme B levels in cellular immune subsets. Gut microbiome analysis revealed distinct and differential diversity and composition within infected groups aligned with clinical severity reflected through the increased abundance of Gammaproteobacteria, reduced Bifidobacteria, and a unique signature mapping to the HCMV infected IgM negative group. Correlation analyses revealed associations between Bifidobacterium breve, Gammaproteobacteria, Firmicutes, Clostridia, Finegoldia magna, Veillonella dispar, and Granzyme B expressing immune cell subsets. Our study describes a novel gut microbiome-immune axis that may influence disease severity in cholestatic infants with active HCMV infection.

Customized Postoperative Therapy Improves Bile Drainage in Biliary Atresia: A Single Center Preliminary Report

BACKGROUND

Controversies in management of biliary atresia (BA) after hepatoportoenterostomy (HPE) lead to variable treatment protocols. We implemented standardized medical management after HPE, customizing the use of antibiotics and corticosteroids based on patient-specific factors.

METHODS

In this retrospective analysis, 20 consecutive infants underwent HPE for BA and were compared to a historical cohort. Analysis of successful biliary drainage 3 months after HPE (defined as serum total bilirubin <2 mg/dL) was the primary endpoint; survival with native liver at 2 years was the secondary endpoint.

RESULTS

Sixteen of 20 (80%) infants had successful bile drainage, compared to 8 of 20 (40%) infants in the historical cohort (P = 0.0225). Sixteen of 20 patients in the new protocol have reached 2 years of age or required liver transplantation. Among the sixteen, 11 (68.8%) are alive with native livers versus 10 of 20 (50%) in the historical cohort (P = 0.0970).

CONCLUSION

This preliminary report suggests the potential benefit of tailored use of postoperative antibiotics and corticosteroids in improving biliary drainage after HPE.

LEVEL OF EVIDENCE

III.

Gut dysbiosis in Thai intrahepatic cholangiocarcinoma and hepatocellular carcinoma

Primary liver cancer (PLC), which includes intrahepatic cholangiocarcinoma (iCCA) and hepatocellular carcinoma (HCC), has the highest incidence of all cancer types in Thailand. Known etiological factors, such as viral hepatitis and chronic liver disease do not fully account for the country's unusually high incidence. However, the gut-liver axis, which contributes to carcinogenesis and disease progression, is influenced by the gut microbiome. To investigate this relationship, fecal matter from 44 Thai PLC patients and 76 healthy controls were subjected to whole-genome metagenomic shotgun sequencing and then analyzed by marker gene-based and assembly based methods. Results revealed greater gut microbiome heterogeneity in iCCA compared to HCC and healthy controls. Two Veillonella species were found to be more abundant in iCCA samples and could distinguish iCCA from HCC and healthy controls. Conversely, Ruminococcus gnavus was depleted in iCCA patients and could distinguish HCC from iCCA samples. High Veillonella genus counts in the iCCA group were associated with enriched amino acid biosynthesis and glycolysis pathways, while enriched phospholipid and thiamine metabolism pathways characterized the HCC group with high Blautia genus counts. These findings reveal distinct landscapes of gut dysbiosis among Thai iCCA and HCC patients and warrant further investigation as potential biomarkers.

Percutaneous transhepatic cholangial drainage or antibiotic therapy worsens response to immunotherapy in advanced cholangiocarcinoma

BACKGROUND

Bile duct obstruction is a common issue for patients with advanced cholangiocarcinoma (CCA). Percutaneous transhepatic cholangial drainage (PTCD) is often required to relieve the obstruction. However, PTCD may alter the intestinal microbiota, which can affect the efficacy of immunotherapy. Antibiotics (ATB) can also have significant immunomodulatory effects by perturbing the gut microbiota. Therefore, this study aimed to investigate whether PTCD or ATB therapy is associated with overall survival (OS) or progression-free survival (PFS) in patients with advanced CCA receiving first-line chemotherapy plus immune checkpoint blockade (ICB) in clinical practice. We also explored whether the gut microbiota changes after receiving PTCD.

METHODS

We conducted a single-center retrospective analysis of PTCD and ATB therapy in patients with advanced CCA. PTCD was performed before ICB initiation, and ATB was administered within 1 month before and 6 weeks after ICB initiation. Our primary outcomes were PFS and OS. Moreover, we used 16s rRNA sequencing to analyze fecal and bile samples obtained from patients who underwent PTCD.

RESULTS

In total, 107 patients with CCA were included. Among patients who did not undergo PTCD, ICB plus chemotherapy significantly improved OS vs. chemotherapy alone (hazard ratio [HR] 0.21, 95% confidence interval [CI] 0.09-0.45, p < 0.0001). PFS was also significantly improved in patients who received ICB plus chemotherapy compared with chemotherapy alone (HR 0.36, 95% CI 0.16-0.80, p = 0.0024). However, ICB plus chemotherapy did not improve survival compared with chemotherapy alone among patients who received PTCD. Overall changes in the fecal microbiota of patients after PTCD involved significant reductions in which Escherichia - Shigella.

CONCLUSIONS

The use of ATB or PTCD in patients with CCA receiving ICB was associated with worse OS compared with chemotherapy alone, and PTCD affects the gut microbiota. Escherichia - Shigella was significantly reduced in feces of patients after PTCD.

Biliatresone: progress in biliary atresia study

BACKGROUND

Biliary atresia (BA) is one of the main causes of neonatal end-stage liver disease. Without timely diagnosis and treatment, most children with BA will develop irreversible liver fibrosis within the first two months. While current theorized causes of BA include viral infection, immune disorders, and genetic defects, the comprehensive etiology is still largely unknown. Recently, biliatresone attracted much interest for its ability to induce BA in both zebrafish and mice, so we summarized the latest progress of biliatresone research in BA and tried to answer the question of whether it could provide further clues to the etiology of human BA.

DATA SOURCES

We conducted a PubMed search for any published articles related to the topic using search terms including "biliary atresia", "biliatresone", "GSH", and "HSP90". Relevant data were extracted from the original text or supplementary materials of the corresponding articles.

RESULTS

Biliatresone had shown its unique toxicity in multiple species such as zebrafish and mice, and pathogenic factors involved included glutathione (GSH), heat shock protein 90 (HSP90) and the related pathways. In combination with epidemiological evidence and recent studies on the intestinal flora in biliary atresia, a new pathogenic hypothesis that the occurrence of biliary atresia is partly due to biliatresone or its structure-like compounds depositing in human body via vegetables or/and the altered intestinal flora structure can be tentatively established.

CONCLUSIONS

Based on the existing evidence, we emphasized that GSH and HSP90 are involved in the development of BA, and the maternal diet, especially higher vegetable intake of Asian women of childbearing age, accompanied by the altered intestinal flora structure, may contribute to the occurrence of biliary atresia and the higher incidence in the Asia group. However, the evidence from large sample epidemiological research is necessary.

Regulatory effects of oral microbe on intestinal microbiota and the illness

Over the past decade, the association between oral health, intestinal microbiota, and systemic diseases has been further validated. Some oral microbial species have been isolated from pathological intestine mucosa or feces and identified as biomarkers for intestinal diseases. A small proportion of oral microbiome passes through or colonizes the lower gastrointestinal tract, even in healthy individuals. Opportunistic pathogens from the oral cavity may expand and participate in the occurrence and progression of intestinal diseases when the anatomical barrier is disrupted. These disruptors interact with the intestinal microbiota, disturbing indigenous microorganisms, and mucosal barriers through direct colonization, blood circulation, or derived metabolite pathways. While interacting with the host's immune system, oral-derived pathogens stimulate inflammation responses and guide the transition of the intestinal microenvironment from a healthy state to a pre-disease state. Therefore, the oral-gut microbiome axis sheds light on new clinical therapy options, and gastrointestinal tract ecology balance necessitates simultaneous consideration of both oral and gut microbiomes. This review summarizes possible routes of oral microbes entering the intestine and the effects of certain oral bacteria on intestinal microbiota and the host's immune responses.

What Makes A "Successful" Kasai Portoenterostomy "Unsuccessful"?

OBJECTIVES

Clearance of jaundice (CoJ) is the first key objective of Kasai portoenterostomy (KPE) for biliary atresia (BA) and its achievement is by far the best index of long-term prognosis. We sought to identify the reasons for failure [subsequent liver transplant (LT)] in this cohort.

METHODS

Review of single-center prospective BA database. Successful KPE was defined by achieving a postoperative bilirubin of ≤20 µmol/L. Pre-KPE and post-KPE variables were identified together with a multivariate logistic regression model to identify those observable at 3 months post-KPE. Data are quoted as median (range). A P value of ≤0.05 was significant.

RESULTS

One hundred thirty-five infants underwent KPE between January 2012 and December 2018, of which 90 (67%) achieved CoJ. From these 20 (22%) (Cohort A) underwent LT with the remainder continuing with native liver (Cohort B) (median follow-up of 4.15 years). There was no difference in age at KPE ( P = 0.41), APRi (aspartate aminotransferase-to-platelet ratio) ( P = 0.07), associated anomalies ( P = 0.7), and cytomegalovirus status ( P = 0.7) between the 2 groups. Postoperatively, both cholangitis [any episode, 18/20 (90%) vs 15/70 (21%); P < 0.0001] and portal hypertension (PHT) [gastrointestinal (GI) bleed, 10/20 (50%) vs 2/70 (2.8%); P < 0.0001] were significantly more common in cohort A. Univariate analysis showed that the most significant predictive values at 3 months for LT by 2 years were high APRi, bilirubin, international normalized ratio, and ultrasound (US)-detected ascites with multivariate logistic modeling confirming these variables with predictive values of r2 = 0.79, AUROC = 0.98.

CONCLUSIONS

Failure is not preordained at KPE but due to recurrent cholangitis and/or symptoms of PHT.

Comprehensive Analysis of Gut Microbiota and Fecal Bile Acid Profiles in Children With Biliary Atresia

Background

Biliary atresia (BA) is the most common cholestatic liver disease in neonates. Herein, we aimed at characterizing the gut microbiota and fecal bile acid profiles of BA patients, defining the correlations between them, and evaluating the relationship between the clinical pathogenesis and changes in the gut microbiota and bile acid profiles.

Methods

A total of 84 fecal samples from BA patients (n = 46) and matched healthy controls (HCs, n = 38) were subjected to sequencing by 16S rRNA gene amplification, and fecal bile acid were analyzed by targeted metabolomics.

Findings

Compared with the controls, a structural separation of the intestinal flora of BA patients was uncovered, which was accompanied by changes in the composition of fecal bile acids. In the BA group, Actinobacillus, Monoglobus, and Agathobacter were enriched in patients without cholangitis (p &lt; 0.05). Selenomonadaceae and Megamonas were more abundant in patients without recurrent cholangitis episodes (p &lt; 0.05), while Lachnospiraceae and Ruminococcaceae were enriched in patients with multiple recurrences of cholangitis (p &lt; 0.05). Postoperative jaundice clearance was associated with Campylobacter and Rikenellaceae (p &lt; 0.05), and tauroursodeoxycholic acid was associated with jaundice clearance (p &lt; 0.001).

Conclusion

BA patients are characterized by different compositions of gut microbiota and bile acids, and their interaction is involved in the process of liver damage in BA, which may be closely related to the occurrence of postoperative cholangitis and jaundice clearance.

Effects of Intestinal FXR-Related Molecules on Intestinal Mucosal Barriers in Biliary Tract Obstruction

Background: The farnesoid X receptor (FXR) is a key factor regulating hepatic bile acid synthesis and enterohepatic circulation. Repression of bile acid synthesis by the FXR is a potential strategy for treating cholestatic liver disease. However, the role of intestinal FXR on the intestinal barrier and intestinal microbiota needs further investigation.

Materials: Intestinal tissues were collected from patients with biliary atresia or without hepatobiliary disease. Then, intestinal mRNA levels of FXR-related molecules were determined. To investigate the effect of FXR activation, bile-duct-ligation rats were treated with obeticholic acid [OCA (5 mg/kg/day)] or vehicle (0.5% methyl cellulose) per oral gavage for 14 days. The mRNA levels of intestinal FXR, SHP, TNF-α, FGF15 and bile acid transporter levels were determined. In addition, the intestinal permeability, morphologic changes, and composition of the intestinal microbiota were evaluated. Gut Microbiome was determined by 16S rDNA MiSeq sequencing, and functional profiling of microbial communities was predicted with BugBase and PICRUSt2. Finally, the role of OCA in injured intestinal epithelial cell apoptosis and proliferation was examined by pretreatment with lipopolysaccharide (LPS) in Caco-2 cells.

Results: The downstream of the FXR in ileum tissues was inhibited in biliary obstruction. Activation of the FXR signaling pathway by OCA significantly reduced liver fibrosis and intestinal inflammation, improved intestinal microbiota, and protected intestinal mucosa in BDL rats. OCA also altered the functional capacities of ileum microbiota in BDL rats. Significant differences existed between the controls and BDL rats, which were attenuated by OCA in the alpha diversity analysis. Principal coordinates analysis showed that microbial communities in BDL rats clustered separately from controls, and OCA treatment attenuated the distinction. Bugbase and PICRUSt2 analysis showed that OCA changed the composition and structure of the intestinal microbiota and improved the metabolic function of the intestinal microbiota by increasing the relative abundance of beneficial bacteria and reducing the relative abundance of harmful bacteria. Moreover, OCA reduced the apoptosis induced by LPS in Caco-2 cells.

Conclusion: The FXR agonist, OCA, activates the intestinal FXR signaling pathway and improves the composition and structure of the intestinal microbiota and intestinal barrier in BDL rats.

Genetic Factors and Their Role in the Pathogenesis of Biliary Atresia

Biliary Atresia, a common basis for neonatal cholestasis and primary indication for Liver Transplantation, accounts for 60% of pediatric Liver Transplantations. While the pathogenesis of Biliary Atresia remains obscure, abnormalities within bile ducts and the liver, inflammation, fibrosis and cilia defects are thought to comprise the pathological basis for this condition. The findings of genetic variants in Biliary Atresia, such as Copy Number Variations and Single Nucleotide Polymorphism, are considered as essential factors in the development of this condition. In this review, we summarize and analyze these Biliary Atresia variants from a perspective of their pathological characteristics. In conclusion, such analyses may offer novel insights into the pathogenesis of Biliary Atresia and provide a foundation for future studies directed toward a better understanding and treatment of Biliary Atresia.

Current and emerging adjuvant therapies in biliary atresia

Following Kasai hepatic portoenterostomy (HPE), most patients with biliary atresia will eventually require liver transplantation due to progressive cirrhosis and liver failure. Preventing liver transplantation, or even delaying eventual liver transplantation, is the key to improving long-term outcomes. This review first examines the commonly used adjuvant therapies in post-HPE biliary atresia and the strength of the evidence supporting these therapies. Next, it examines the evolving frontiers of management through a comprehensive evaluation of both recently completed and ongoing clinical trials in biliary atresia. Promising therapies used in other cholestatic liver diseases with potential benefit in biliary atresia are discussed. Improving post-HPE management is critical to prevent complications, delay liver transplantation, and ultimately improve the long-term survival of patients with biliary atresia.