Table 4.

Specific microorganism or dysbiosis of microbiome in hepatobiliary-pancreatic cancers

Specific microorganism or dysbiosis of the microbiome	Findings (References)
Hepatocellular carcinoma
Fecal microbiome	The amount of Gemmiger, Parabacteroides, and Paraprevotella were increased in fecal specimens from patients with hepatocellular carcinoma, compared with those with liver cirrhosis (Ren et al. 2019).
Helicobacter species	Helicobacter species were detected in hepatocellular carcinoma tissue specimens (Huang et al. 2004; Kruttgen et al. 2012; Rocha et al. 2005). Helicobacter hepaticus can suppress the innate immunity to recognize and eliminate tumor cells in a mouse model of hepatocellular carcinoma (Fox et al. 2010).
Escherichia coli	The amount of Escherichia coli was increased in fecal specimens from patients with hepatocellular carcinoma (Grat et al. 2016).
Clostridium species	Clostridium species can inhibit the accumulation of hepatic natural killer T cells and suppress antitumor immune response in mouse models of both primary and secondary liver tumors (Ma et al. 2018)
Biliary tract cancer
Fecal microbiome	The amounts of Lactobacillus, Actinomyces, Peptostreptococcaceae, and Alloscardovia were increased in fecal specimens from patients with intrahepatic cholangiocarcinoma compared with healthy individuals (Jia et al. 2019).
Bile microbiome	Dysbiosis in the bile microbiome was associated with biliary mucosal dysplasia or cholangiocarcinoma (Chen et al. 2019b; Pereira et al. 2017).
Helicobacter species	The presence of Helicobacter pylori, Helicobacter bilis, or Helicobacter hepaticus in tumor tissue was associated with increased risk of biliary tract cancers (Bulajic et al. 2002; Fukuda et al. 2002; Murphy et al. 2014; Segura-Lopez et al. 2015; Shimoyama et al. 2010; Zhou et al. 2013).
Biliary mucosal microbiome	Bifidobacteriaceae, Enterobacteriaceae and Enterococcaceae were enriched in cholangiocarcinoma tissue (Chng et al. 2016). The amount of Nesterenkonia was decreased, whereas the amounts of Methylophilaceae, Fusobacterium, Prevotella, Actinomyces, Novosphingobium and Helicobacter pylori were increased in extrahepatic cholangiocarcinoma tissue (Aviles-Jimenez et al. 2016).
Salmonella typhi	Chronic Salmonella typhi infection was associated with gallbladder cancer (Nagaraja and Eslick 2014).
Pancreatic cancer
Pancreatic tissue microbiome	Pseudomonas and Elizabethkingia were enriched in pancreatic cancer tissue. Intestinal microbes can migrate from the gut to the pancreas and inhibit T-cell-mediated immune responses against pancreatic tumors through the recruitment of myeloid-derived suppressor cells into the tumor microenvironment in a mouse model (Pushalkar et al. 2018). The presence of Pseudoxanthomonas, Streptomyces, or Saccharopolyspora in pancreatic cancer tissue was associated with high density of CD8+ T-cells in tumor tissue and better overall survival (Riquelme et al. 2019).
Fungal microbiome	Malassezia was enriched in pancreatic carcinoma tissue (Aykut et al. 2019).
Oral microbiome	High amounts of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Neisseria elongata, and Streptococcus mitis in the oral cavity were associated with pancreatic cancer (Farrell et al. 2012). High amounts of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in the oral cavity were associated with pancreatic cancer (Fan et al. 2018).
Fusobacterium	Fusobacterium nucleatum was detected in tumor tissue of intraductal papillary mucinous neoplasms with high-grade dysplasia (Gaiser et al. 2019). High amount of Fusobacterium species in tumor tissue was associated with worse prognosis in pancreatic cancer (Mitsuhashi et al. 2015).