Alterations of the Gut Microbiome in Chronic Hepatitis B Virus Infection Associated with Alanine Aminotransferase Level

Abstract

The changes in the gut microbiota of healthy hepatitis B virus (HBV) carriers, including asymptomatic and non-cirrhotic subjects, have been rarely scrutinized. From 1463 faecal samples in health examinees, in total 112 subjects, including 36 hepatitis B surface antigen (HBsAg)-positive and 76 control subjects, were included. Twenty-eight of 36 HBsAg-positive individuals (78%) showed normal alanine aminotransferase (ALT) levels (normal ALT group), whereas eight subjects exhibited elevated ALT levels (22%, high ALT group). By using 16S rRNA gene sequencing, the distance between normal and high ALT groups among HBsAg-positive subjects showed a significant separation after the pairwise comparison of weighted UniFrac distance (permutational analysis of variance <i>q</i>-value = 0.039), when compared with the distances to the control group. In comparison with the control group, the normal ALT group had <i>Anaerostipes</i> as a significant taxon that showed a positive association (Coefficient (<i>Coef.</i>) = 0.028, <i>q</i> = 0.039). <i>Desulfovibrio</i> (<i>Coef.</i> = 0.54, <i>q</i> = 0.014) and <i>Megasphaera</i> (<i>Coef.</i> = 1.41, <i>q</i> = 0.030) showed positive correlations, and <i>Acidaminococcus</i> (<i>Coef.</i> = -1.31, <i>q</i> = 4.15 × 10^-75) exhibited a negative correlation with high ALT level. Gut microbial composition was different according to HBV-induced serum ALT levels, indicative of a potential link between gut and liver metabolism.