Background/Aims: This prospective longitudinal study described changes in gut microbiota in patients with alcoholic hepatitis

(AH) and alcoholic cirrhosis (AC) and the relationship with clinical parameters.

Methods: Included patients had histologically confirmed AH or AC with a 6-month follow-up (FU). Data were collected at baseline, 3 and 6 months: fecal microbiota, alcohol intake, MELD score and blood tests, body composition, nutritional intake and energy expenditure. Changes in non-metagenomics data over time were assessed using multiple linear regression. PERMANOVA, DESeq2 and Wilcoxon tests were used for metagenomic comparisons, and DISTLM for correlations between clinical and metagenomic data.

Results: We included 10 AH patients and 12 AC patients. During FU, 6 AH and 4 AC patients became alcohol abstinent. Compared to AH, AC patients had decreased C-reactive protein (p = 0.009) and serum bilirubin levels (p = 0.002) and MELD score (p = 0.006), and increased albumin levels (p = 0.002). Overall microbiota profiles differed between groups at baseline (p < 0.001). While only few taxa changed in abundance in AC patients, AH patients demonstrated a decrease of 20 oral bacteria and an increase of 10 shortchain fatty acid-producing bacteria. The relationship between abundance of gut microbiota and body weight and muscle mass at baseline and at 6 months in AC was no more significant after correction for multiple testing.

Conclusion: Baseline microbiota profile differs in AH and AC. Gut dysbiosis changes are limited to AH, without significant

correlation with clinical parameters nor with alcohol intake. Larger studies are needed.