# Oral Microbiome Diversity Matters on Nucleos(t)ide Analogue Cessation in Chronic Hepatitis B

## TL;DR

This study finds that the diversity of oral microbes may predict treatment outcomes in hepatitis B patients stopping a specific therapy.

## Contribution

The study is the first to explore the oral microbiome's role in predicting outcomes after stopping nucleos(t)ide analogues in hepatitis B.

## Key findings

- Patients with favorable outcomes had higher oral microbiome diversity and lower variation in microbial composition.
- Specific oral bacteria like Prevotella were linked to better outcomes, while Haemophilus and Porphyromonas were associated with poor outcomes.
- A microbiome-based model outperformed clinical markers in predicting treatment outcomes.

## Abstract

Withdrawal of nucleos(t)ide analogue (NUC) therapy in hepatitis B e antigen (HbeAg)-negative chronic hepatitis B (CHB) may lead to functional cure in a subset of patients. Although gut microbiota is known to influence both CHB progression and treatment outcomes, the oral microbiome in NUC cessation remains unexplored.

This longitudinal study explored the oral microbiome in patients with CHB on NUC therapy > 2 years having a planned NUC cessation. Oral microbiome composition was analyzed in 110 saliva samples across 7 time points from 18 HBeAg-negative patients with 36 months follow-up. Favorable outcome was defined as either HBsAg loss or decline of > 1 log10 or sustained off-therapy HBV DNA level < 2000 IU/mL during year 3. Hepatic flare was defined as alanine transaminase (ALT) > 80 U/L or 2 × baseline level.

The overall microbial composition remained stable during the study period. Patients with favorable outcome showed consistently higher alpha diversities (P < .001) from baseline, with lower intersample variations across all time points (P < .05), compared to unfavorable. Hepatitis B surface antigen (HBsAg), ALT, and aspartate transaminase (AST) correlated inversely with several Prevotella taxa and specific pathways (Spearman ρ > −0.5, P < .01). Unfavorable outcome and high HBsAg level correlated with opportunistic taxa Haemophilus parainfluenzae and Porphyromonas catoniae. Random forest model incorporating validated microbial markers predicting favorable versus unfavorable outcome achieved higher predictive performance than clinical markers alone (area under curve, 0.79 vs 0.66).

Our exploratory study suggests that oral microbiome profiling at NUC cessation in HBeAg-negative CHB could support prognostication of virological outcome.

Clinical Trials Registration. NCT03681132.

This 3-year longitudinal study identifies a novel association between the oral microbiome profile and the clinical outcome after withdrawal of nucleos(t)ide analogues in chronic hepatitis B, indicative of potential applications in oral microbiome-based prediction and development of personalized treatment strategies.