Gut microbiome in non-alcoholic fatty liver disease associated hepatocellular carcinoma: Current knowledge and potential for therapeutics

Table 1 Microbiota profiles in liver disease

Study	Bacterial species increased	Bacterial species decreased	Putative impact of microbial change in group	Comparison group
Advanced fibrosis/cirrhosis
Loomba et al[49], 2017, Cell Metab	Proteobacteria Include E. coli	Firmicutes	Higher incidence of enzymes for butyrate, and lower for lactate and acetate	NAFLD advanced fibrosis/cirrhosis compared to NAFLD mild/moderate fibrosis
Ponziani et al[18], 2019, Hepatology	Phylum: Proteobacteria, Bacteroidetes, Cyanobacteria; Family: Lactobacillaceae, Enterobacteriaceae, Prevotellaceae, Bacteroidaceae, Streptococcaceae, Enterococcaceae, Veillonellaceae	Phylum: Verrucomicrobia; Family: Verrucomicrobiaceae; Methanobacteriaceae	Intestinal inflammation, Increase in Intestinal permeability, increased systemic inflammation	NAFLD cirrhosis compared to healthy controls
HCC
Ren et al[52], 2019, Gut	Phylum: Acinetobacter; Genus: Gemmiger, Parabacteroides, Paraprevotella, others	Phylum: Verrucomicrobia	Increased LPS producer with liver inflammation and oxidative damage; Decreased butyrate production resulting in intestinal mucosal disruption	Early HCC compared to cirrhosis
Ren et al[52], 2019, Gut	Genus: Klebsiella, Haemophilus	Verrucomicrobia (Akkermansia); Genus: Alistipes, Phascolarctobacterium, Ruminococus	Increased LPS producer with liver inflammation and oxidative damage; Decreased butyrate production resulting in intestinal mucosal disruption	Early HCC compared to healthy controls
Ponziani et al[16], 2019, Hepatology	Phylum: Bacteroidetes; Family: Bacteroidaceae, Streptococcaceae, Enterococcaceae	Family: Verrucomicrobiaceae, Bifidobacteriaceae	Intestinal inflammation, Increase in Intestinal permeability, increased systemic inflammation	HCC in NAFLD Compared to NAFLD cirrhosis without HCC
Grat M et al[15], 2016, Transplant Proc	E. coli		LPS and inflammation within liver	HCC cirrhosis Compared to non-HCC cirrhosis

Selected studies (human) showing different microbiota profiles in cirrhosis and hepatocellular carcinoma (HCC) with emphasis on non-alcoholic fatty liver disease associated HCC. HCC: Hepatocellular carcinoma; NAFLD: Non-alcoholic fatty liver disease; LPS: Lipopolysaccharide.