Signature pathogenic bacteria in tongue coating drive the progression of chronic hepatitis B complicated with fatty liver disease via the “Oral-gut-liver axis” by regulating glucose and lipid metabolism

Abstract Objective To compare the characteristics of tongue coating flora in healthy people, patients with chronic hepatitis B (CHB) and patients with CHB complicated with non-alcoholic fatty liver disease (NAFLD), and to explore the characteristics of tongue coating flora in patients with CHB complicated with NAFLD and its comorbidity mechanism. Methods From January 2024 to December 2024, 42 with CHB complicated with NAFLD patients with CHB complicated with NAFLD(CHB complicated with NAFLD group) and 34 patients with simple CHB (simple CHB group) were subjected in our department, and 28 healthy individuals were selected and served as control group. Baseline clinical data were collected from all the participants, and intergroup differences were analyzed. After tongue coating samples were harvested for 16S ribosomal RNA (16S rRNA) sequencing using the PacBio Sequel sequencing platform. After sequence quality control, denoising, and amplicon sequence variant (ASV) clustering, the microbial composition, α diversity, and β diversity were analyzed in the 3 sample groups. Linear discriminant analysis effect size (LEfSe) was used to screen for intergroup differential marker species, by linear discriminant analysis (LDA) score >2 and P