Alteration in tongue coating microbiota across different stages of hepatitis B virus-related chronic liver disease

Background: Hepatitis B virus-related chronic liver disease (HBV-CLD), chronic hepatitis B (CHB), liver cirrhosis (LC), and hepatocellular carcinoma (HCC) patients' tongue coating microbiota dysbiosis has not yet been clearly defined. Objectives: We aimed to reveal shifts in the bacterial composition of tongue coating microbiota during the progression of HBV-CLD in three different phases. Design: We examined tongue coating microbiota of 16 healthy individuals and 81 patients with HBV-CLD, including 25 with CHB, 27 with LC, and 29 with HCC, using 16S rRNA gene sequencing technique. Results: < 0.05). Linear discriminant analysis revealed multiple taxa that varied significantly in abundance between healthy controls and patients with HBV-CLD; Firmicutes were higher in patients with LC and HCC, whereas CHB patients had higher levels of Bacteroidetes. PICRUSt2 analysis of the sequencing data revealed changes in microbial activity with disease development. Conclusions: Our investigation revealed tongue coating microbiota dysbiosis in patients with HBV-CLD, which may offer unique diagnostic possibilities and provide microbial biomarkers for monitoring disease progression.