Profiling of tumour-associated microbiota in human hepatocellular carcinoma

Abstract

Liver cancer is the fourth leading cause of cancer-related death. Hepatocellular carcinoma (HCC) is a primary liver cancer that results from chronic hepatitis caused by multiple predisposing factors such as viral infection, alcohol consumption, and non-alcoholic fatty liver disease. Accumulating studies have indicated that dysfunction of the gut epithelial barrier and hepatic translocation of gut microbes may be implicated in the pathogenesis of HCC. However, the translocated bacteria in HCC patients remains unclear. Here, we characterised tumour-associated microbiota in patients with liver cancer and focused on HCC. We observed that the number of amplicon sequence variants in tumour-associated microbiota was significantly higher compared with that in non-tumour regions of the liver. The tumour-associated microbiota consisted of Bacteroidetes, Firmicutes, and Proteobacteria as the dominant phyla. We identified an unclassified genus that belonged to the Bacteroides, Romboutsia, uncultured bacterium of Lachnospiraceae as a signature taxon for primary liver cancer. Additionally, we identified Ruminococcus gnavus as a signature taxon for HCC patients infected with hepatitis B and/or hepatitis C viruses. This study suggests that tumour microbiota may contribute to the pathology of HCC.

A Predictive Model Based on the Gut Microbiota Improves the Diagnostic Effect in Patients With Cholangiocarcinoma

“…The increase of intestinal permeability promoted the migration of bacteria and the elevation of serum lipopolysaccharide, following with an increase of inflammatory response caused by Toll-like receptor 4 (TLR4) and eventually promoting the progression of chronic liver disease and tumorigenesis (Lin et al, 1995;Dapito et al, 2012). In addition, present study has indicated a positive correlation between gut microbiota and mortality in patients with alcoholic hepatitis (Komiyama et al, 2021). All this evidence confirmed bacterial translocation is concerned with the progression of other liver diseases.…”

A More Diverse Cervical Microbiome Associates with Better Clinical Outcomes in Patients with Endometriosis: A Pilot Study

“…In addition, Chlamydia infection, one of the upregulated genera in the (+/+) patients ( Figure 5 d), has been associated with increased risks to develop cervical or ovarian cancer [ 67 , 68 ]. Ruminococcus_1 , another upregulated genus ( Figure 5 d), was also defined as a tumor-associated microbiota [ 69 , 70 ]. Those findings suggest possible links of altered cervical microbiome with more aggressive phenotypes in endometriosis patients.…”

Role of Microbiota in Viral Infections and Pathological Progression

“…Animal experiments suggested that anti-HBV activity is based on the regulation of the immune system by intestinal bacteria [ 98 , 99 ]. Several recent studies have shown a correlation between the intestinal microbiota and chronic HBV infection without liver injury [ 99 , 100 , 101 , 102 ], as well as HBV-related cirrhosis and hepatocellular carcinoma [ 103 , 104 , 105 , 106 , 107 ].…”