Abstract: Objective To evaluate the impact of probiotic adjuvant therapy on the gut microbiota compostion and clinical prognosis of patients with acute-on-chronic liver failure (ACLF). Methods In our hospital, 84 patients diagnosed with ACLF were randomly divided into two groups. The control group received conventional symptomatic treatment, while the observation group was treated with both conventional treatment and gut microbiota. The bacterial distribution, levels of immune factors [CD4⁺, CD8⁺], inflammatory factors,and liver function indicators [ALT, AST, GGT, TBil] between the two groups were compared. Both groups were followed up for 1 year to observe their survival rates. Results Before treatment, the number of lactobacillus and bifidobacteria in the observation group was (6.9±0.8) log₁₀nCFU/g, and (5.5±0.9) log₁₀nCFU/g, respectively, while the counts of Escherichia coli and coliforms were (9.2±1.4) log₁₀nCFU/g (8.8±0.4) log₁₀nCFU/g, respectively. After treatment, the counts of lactobacilli and bifidobacteria were (8.4±0.6) log₁₀nCFU/g, and (9.7±0.8) log₁₀nCFU/g, respectively, whereas the counts of Escherichia coli and coliforms were (5.9±0.5) log₁₀nCFU/g, and (6.1±0.4) log₁₀nCFU/g, respectively. For the control group, before treatment, the counts of lactobacillus and bifidobacteria were(6.8±0.7) log₁₀nCFU/g and (5.4 ± 0.8) log₁₀nCFU/g, respectively., The counts of Escherichia coli and coliforms were (9.0±1.3) log₁₀nCFU/g, and (8.7 ± 0.4) log₁₀nCFU/g, respectively. Post-treatment, lactobacilli and bifidobacteria counts were(7.7±0.6) log₁₀nCFU/g, (7.6±0.8) log₁₀nCFU/g, respectively, while Escherichia coli and coliforms counts were (6.8±0.5) log₁₀nCFU/g and (7.2±0.5) log₁₀nCFU/g, respectively. Post-treatment counts of lactobacilli and bifidobacteria in the observation group were significantly higher than their pre-treatment values and those in the control group. Conversely, the counts of Escherichia coli and coliforms were significantly lower post-treatment compared to pre-treatment and those in the control group (P<0.05). Before treatment, the levels of CD4⁺, IL-6 and IL-10 in the observation group were (32.8±5.4)%, (87.1±11.2) pg/mL and (31.8±4.4) pg/mL respectively. After treatment, the levels of GGT, alt, AST and TBil were(49.2±11.0)U/L, (59.6±9.2)U/L, (45.2±9.1)U/L, (158.6±18.6)μmol/L respectively. In the control group, the levels of GGT, ALT, AST and TBil before treatment were (62.04±11.18) U/L, (84.5±11.5) U/L, (97.5±21.5) U/L, (314.5±20.3) U/L, respectively μmol/L; After treatment, the levels of GGT, AST, AST and TBil were (53.7±12.3) U/L, (62.5 ±10.9) U/L, (48.5±9.2) U/L and (162.8±20.3)μmol/L, respectively. After treatment, liver function indices in both groups were significantly lower than their pre-treatment levels in the same group (P<0.05). The 1-year cumulative survival rate was 83.33% (35/42) in the observation group compared to 78.57% (33/42) in the control group. Conclusion The application of probiotics in ACLF patients can suppress the proliferation of harmful intestinal bacteria, enhance immune and liver functions, and potentially lead to better clinical outcomes.

Key words: Probiotics, Acute-on-chronic liver failure, gut microbiota, Prognosis, Liver function