Microbiome of Hepatobiliary Diseases

Hepatobiliary and pancreatic cancers are associated with poor prognosis owing to their high level of tumor invasiveness, recurrence, hematogenous and lymphatic metastasis, resistance to firstline chemotherapy, and lack of effective target therapy [1,2]. Evidence in the literature suggests that hepatobiliary and pancreatic cancers develop through the accumulation of genetic and epigenetic alterations, which is influenced by host immune state, food, and environmental and microbial exposures [1-4]. The human microbiota is the collection of microorganisms exists in the human being, and the relationships with microorganisms and host can be considered to maintain a wide range of the spectrum, from mutualism to pathogen [5]. Abrupt changes in the microbiota of various human body areas associate with diverse localized or systemic human diseases. The human gastrointestinal tract is one of the biggest storing spaces of microbes in the body and contains both commensal and pathogenic microbial species [6]. Research on intestinal microbiota has shown that inflammatory bowel disease is originated from the varied composition of microbial composition and abnormal and overflowing mucosal immune response [7]. Numerous pathogens can promote cancer through well-identified mechanisms [8]. Although most studies are confined to specific bacterial pathogens and viruses, the link between human cancer and bacterial microbiota has recently been studied actively by using next-generation sequencing technology for microbiome profiling [9]. There is an increasing interest in understanding the role of microbiome as a microenvironment for cancer development, particularly in the area of hepatobiliary and pancreatic cancers [10]. The liver, biliary tract, and pancreas are located in very close Review