Opisthorchiasis and the Microbiome

Mechanistic insights into liver-fluke-induced bile-duct cancer

Liver fluke infection is a major risk for cholangiocarcinoma (CCA). It has been established that the Asian liver flukes, Clonorchis sinensis and Opisthorchis viverrini secrete growth factors, digestive enzymes, and extracellular vesicles (EVs) which contribute to abnormal cell development in the bile ducts where the worms reside. These secretions - combined with aberrant inflammation and repeated cycles of chronic wounding at the site of parasite attachment and grazing on the epithelium - promote biliary hyperplasia and fibrosis and ultimately malignant transformation. Application of post-genomic and gene-editing tools to the study of liver fluke immunobiology and pathogenesis has accelerated the discovery of essential virulence factors to which targeted therapies and diagnostics can be directed.

Probiotics as a strategy for addressing helminth infections in low-income countries: Working smarter rather than richer

Helminth infections, which affect approximately 1.5 billion individuals worldwide (mainly children), are common in low- and middle-income tropical countries and can lead to various diseases. One crucial factor affecting the occurrence of these diseases is the reduced diversity of the gut microbiome due to antibiotic use. This reduced diversity compromises immune health in hosts and alters host gene expression through epigenetic mechanisms. Helminth infections may produce complex biochemical signatures that could serve as therapeutic targets. Such therapies include next-generation probiotics, live biotherapeutic products, and biochemical drug approaches. Probiotics can bind ferric hydroxide, reducing the iron that is available to opportunistic microorganisms. They also produce short-chain fatty acids associated with immune response modulation, oral tolerance facilitation, and inflammation reduction. In this review, we examine the potential link between these effects and epigenetic changes in immune response-related genes by analyzing methyltransferase-related genes within probiotic strains discussed in the literature. The identified genes were only correlated with methylation in bacterial genes. Various metabolic interactions among hosts, helminth parasites, and intestinal microbiomes can impact the immune system, potentially aiding or hindering worm expulsion through chemical signaling. Implementing a comprehensive strategy using probiotics may reduce the impact of drug-resistant helminth strains.

Profiles of biliary microbiota in biliary obstruction patients with Clonorchis sinensis infection

Background

Clonorchis sinensis (C. sinensis) is a epidemiologically significant food-borne parasite, causing several hepatobiliary diseases. Biliary microbiota community structure might be influenced by infection with pathogens. However, the biliary microbiome of biliary obstruction patients infected with C. sinensis is still an unexplored aspect.

Methods

A total of 50 biliary obstruction patients were enrolled, including 24 infected with C. sinensis and 26 non-infected subjects. The bile samples were collected by Endoscopic Retrograde Cholangiopancretography. Biliary microbiota alteration was analyzed through high-throughput 16S ribosomal RNA (rRNA) gene sequencing.

Results

Our findings revealed that there was significant increase in both richness and diversity, as well as changes in the taxonomic composition of the biliary microbiota of C. sinensis infected patients. At the phylum level, C. sinensis infection induced Proteobacteria increased and Firmicutes reduced. At the genus level, the relative abundance of Pseudomonas and Staphylococcus increased significantly, while Enterococcus decreased prominently in infected groups (P < 0.05). The PICRUSt analysis further showed remarkably different metabolic pathways between the two groups.

Conclusion

C. sinensis infection could modify the biliary microbiota, increasing the abundance and changing the phylogenetic composition of bacterial in biliary obstruction patients. This study may help deepen the understanding of the host-biliary microbiota interplay with C. sinensis infection on the background of biliary obstruction and provide new insights into understanding the pathogenesis of clonorchiasis.

Fish and Food-Fatale: Food-borne Trematode Opisthorchis viverrini and Cholangiocarcinoma

Neglected Tropical Diseases (NTDs) are a group of communicable diseases with a long history with human beings. NTDs are the proxy of poverty since they affect those in low-income and extreme-poverty populations, as those populations lack access to proper health care, clean water, sanitary conditions, and hygiene. NTDs create losses for a nation that come from the health and the economic sectors as well since the costs of diagnosis, prevention, and treatment strain the national purse strings. One of the 20 different forms of NTDs on the list is food-borne trematodes, comprises of Fasciola, Paragonimus, Clonorchis, and Opisthorchis. Currently, it is estimated that food-borne trematodes can cause a devastating effect on mortality and morbidity. All of them are zoonotic, as humans become infected by ingestion of a second intermediate host, such as freshwater snails, fish, or water vegetables. Opisthorchis viverrini, one of the food-borne trematodes that can be found mostly in South East Asia regions, especially in the Mekong basin, is regarded as a group 1 carcinogen leading to cholangiocarcinoma (CCA). This study aims to present the updated review of Opisthorchis viverrini and CCA.

Revision of potential prognostic markers of cholangiocarcinoma for clinical practice

INTRODUCTION

Cholangiocarcinoma (CCA) is an aggressive cancer arising from any part of the biliary system. Effective treatment of CCA remains limited, resulting in the poor overall prognosis of patients. The effective prognostic biomarkers for CCA remain lacking, and most are at the research level.

AREAS COVERED

The incidences of CCAs, classification, genetic and molecular characteristics, and distinct clinical outcomes in each subtype are introduced. The prognostic markers currently used in clinical practice are reviewed. Studies of biomarkers in defining the aggressiveness of CCA, identifying patients with a potential tumor recurrence, and predicting the survival time, are reviewed. Emerging biomarkers discovered from advanced high throughput technology over the past five years are updated and summarized. Finally, in-depth and critical revision on the prognostic biomarkers for CCA reported from various sources of specimens, e.g. tissues, blood, bile, etc. are discussed.

CONCLUSION

Many prognostic biomarkers for CCA have been proposed and hold promising clinical value. However, these markers are rarely used in the real clinical world due to several factors. Understanding the roles and importance of these prognostic markers may fundamentally impact the therapeutic management of CCA, and hopefully, improve the development of custom and patient-directed therapies for CCA.

Impact of helminth-microbiome interactions on childhood health and development-A clinical perspective

Humans have co-existed with parasites for virtually the entirety of our existence as a species. Today, nearly one third of the human population is infected with at least one helminthic species, most of which reside in the intestinal tract, where they have co-evolved alongside the human gut microbiota (GM). Appreciation for the interconnected relationship between helminths and GM has increased in recent years. Here, we review the evidence of how helminths and GM can influence various aspects of childhood development and the onset of paediatric diseases. We discuss the emerging evidence of how many of the changes that parasitic worms inflict on their host is enacted through gut microbes. In this light, we argue that helminth-induced microbiota modifications are of great importance in both facing the global challenge of overcoming parasitic infections, and in replicating helminthic protective effects against inflammatory diseases. We propose that deepening our knowledge of helminth-microbiota interactions will uncover novel, safer and more effective therapeutic strategies in combatting an array of childhood disorders.

Dysbiosis in the Human Microbiome of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the most common malignant tumor of the biliary system with a very poor prognosis. The human microbiome, which is the sum of the genetic information of human microorganisms, plays an important role in regulating the digestion, absorption, immune response, and metabolism of the host. Increasing evidence indicates a close relationship between CCA and the human microbiome. Specific alterations occur in the human microbiome of patients with CCA. Therefore, in this review, we aimed to summarize the recent evidence on dysbiosis in the human microbiome of CCA. Then, we generalized the effect of Helicobacter pylori on CCA. Additionally, the potential mechanism of human microbial dysbiosis promoted the progress of CCA, and its precancerous disease was also explored. Furthermore, the possibility of the human microbiome as a diagnostic and therapeutic target of CCA was discussed.

Gut microbiota and immune system in liver cancer: Promising therapeutic implication from development to treatment

Liver cancer is a leading cause of death worldwide, and hepatocellular carcinoma (HCC) is the most frequent primary liver tumour, followed by cholangiocarcinoma. Notably, secondary tumours represent up to 90% of liver tumours. Chronic liver disease is a recognised risk factor for liver cancer development. Up to 90% of the patients with HCC and about 20% of those with cholangiocarcinoma have an underlying liver alteration. The gut microbiota-liver axis represents the bidirectional relationship between gut microbiota, its metabolites and the liver through the portal flow. The interplay between the immune system and gut microbiota is also well-known. Although primarily resulting from experiments in animal models and on HCC, growing evidence suggests a causal role for the gut microbiota in the development and progression of chronic liver pathologies and liver tumours. Despite the curative intent of "traditional" treatments, tumour recurrence remains high. Therefore, microbiota modulation is an appealing therapeutic target for liver cancer prevention and treatment. Furthermore, microbiota could represent a non-invasive biomarker for early liver cancer diagnosis. This review summarises the potential role of the microbiota and immune system in primary and secondary liver cancer development, focusing on the potential therapeutic implications.

A comparative study of Helicobacter pylori infection in hamsters experimentally infected with liver flukes Opisthorchis felineus, Opisthorchis viverrini, or Clonorchis sinensis

Helicobacter pylori causes a wide range of human diseases including cancer. Carcinogenic foodborne trematodes Opisthorchis viverrini, Clonorchis sinensis, and O. felineus might promote transmission and spread of H. pylori infection in the definitive mammalian host, which in turn might contribute to the liver fluke-associated malignancy. Our objectives were to find out whether liver flukes O. felineus, O. viverrini, and C. sinensis are carriers of Helicobacter pylori and to determine whether H. pylori is present in feces, bile, and stomach samples from the experimentally infected hamsters. We found that liver flukes are not reservoirs of H. pylori. Nevertheless, the prevalence of H. pylori and the H. pylori ureA gene copy number were significantly elevated after the infection. Overall, although the liver flukes O. felineus, C. sinensis, and O. viverrini are not reservoirs of H. pylori, the infection with the liver flukes significantly modifies the biliary and gut microbiota by increasing H. pylori abundance. This may be a feature of any liver fluke pathogenesis that have not previously been taken into account. Our findings appear to be novel in terms of comparative assessment of the host microbiota and Helicobacter abundance during epidemiologically important liver fluke infections.

Intrahepatic cholangiocarcinoma: Morpho-molecular pathology, tumor reactive microenvironment, and malignant progression

Intrahepatic cholangiocarcinoma (iCCA) is a relatively rare, but highly lethal and biologically complex primary biliary epithelial cancer arising within liver. After hepatocellular carcinoma, iCCA is the second most common primary liver cancer, accounting for approximately 10-20% of all primary hepatic malignancies. Over the last 10-20 years, iCCA has become the focus of increasing concern largely due to its rising incidence and high mortality rates in various parts of the world, including the United States. The challenges posed by iCCA are daunting and despite recent progress in the standard of care and management options for iCCA, the prognosis for this cancer continues to be dismal. In an effort to provide a framework for advancing our understanding of iCCA malignant aggressiveness and therapy resistance, this review will highlight key etiological, biological, molecular, and microenvironmental factors hindering more effective management of this hepatobiliary cancer. Particular focus will be on critically reviewing the cell origins and morpho-molecular heterogeneity of iCCAs, providing mechanistic insights into high risk fibroinflammatory cholangiopathies associated with iCCA development, and notably discussing the deleterious role played by the tumor reactive desmoplastic stroma in regulating iCCA malignant progression, lymphangiogenesis, and tumor immunobiology.

Baseline Gut Microbiota Composition Is Associated With Schistosoma mansoni Infection Burden in Rodent Models

In spite of growing evidence supporting the occurrence of complex interactions between Schistosoma and gut bacteria in mice and humans, no data is yet available on whether worm-mediated changes in microbiota composition are dependent on the baseline gut microbial profile of the vertebrate host. In addition, the impact of such changes on the susceptibility to, and pathophysiology of, schistosomiasis remains largely unexplored. In this study, mice colonized with gut microbial populations from a human donor (HMA mice), as well as microbiota-wild type (WT) animals, were infected with Schistosoma mansoni, and alterations of their gut microbial profiles at 50 days post-infection were compared to those occurring in uninfected HMA and WT rodents, respectively. Significantly higher worm and egg burdens, together with increased specific antibody responses to parasite antigens, were observed in HMA compared to WT mice. These differences were associated to extensive dissimilarities between the gut microbial profiles of each HMA and WT groups of mice at baseline; in particular, the gut microbiota of HMA animals was characterized by low microbial alpha diversity and expanded Proteobacteria, as well as by the absence of putative immunomodulatory bacteria (e.g. Lactobacillus). Furthermore, differences in infection-associated changes in gut microbiota composition were observed between HMA and WT mice. Altogether, our findings support the hypothesis that susceptibility to S.mansoni infection in mice is partially dependent on the composition of the host baseline microbiota. Moreover, this study highlights the applicability of HMA mouse models to address key biological questions on host-parasite-microbiota relationships in human helminthiases.

Cholangiocyte derived carcinomas and local microbiota

Trillions of bacteria are present in the gastrointestinal tract as part of the local microbiota. Bacteria have been associated with a wide range of gastrointestinal diseases including malignant neoplasms. The association of bacteria in gastrointestinal and biliary tract carcinogenesis is supported in the paradigm of Helicobacter pylori and intestinal-type gastric cancer. However, the association of bacterial species to a specific carcinoma, different from intestinal-type gastric cancer is unresolved. The relationship of bacteria to a specific malignant neoplasm can drive clinical interventions. We review the classic bacteria risk factors identified using cultures and PCR (polymerase chain reaction) with new research regarding a microbiota approach through 16S rRNA (16S ribosomal ribonucleic acid gene) or metagenomic analysis for selected carcinomas in the biliary tract.

Saposin-like proteins in Opisthorchis felineus and related opisthorchids

Saposin B domain-containing or saposin-like proteins (SAPs, SAPLIPs) have been described as lipid/membrane-binding and often show antibacterial and cytolytic activity. Members of this protein family are present in phylogenetically distant organisms, pointing to their functional importance. Several SAPs are found in trematodes and some of them apparently are related to host-parasite interaction as they show cytolytic activity or immunogenicity. In the present study, we search for SAP genes of Opisthorchis felineus, Clonorchis sinensis and O. viverrini, compare and analyze their structure and expression patterns. We define three orthologous groups of SAPs in opisthorchids and suggest a unique protein motif with unknown function in one group of orthologs.