When further analyzing stratified additional clinical characteristics in the HCC group, Bacteroides (p = 0.0152), Lachnospiracea incertae sedis (p = 0.0249), Clostridium XIVa (p = 0.0168), and Parabacteroides (p = 0.006) were significantly enriched in non-small HCC subgroup compared with small HCC subgroup (Fig. 2f, g); however, these three genera showed no difference in patients with cirrhotic HCC, portal hypertension, or low-albumin levels (Additional file 1: Fig. S4). This evidence concerns the gene ALB and hepatocellular carcinoma.