Evaluating the Efficacy of Probiotics on Inflammatory Cytokines in Alcoholic Liver Disease: A Focus on IL-6 and IL-10.

Background: While probiotics may offer therapeutic benefits for alcoholic liver disease (ALD), their impact on inflammatory markers in ALD patients is still uncertain. Objective: This study aims to investigate the effects of probiotic supplementation on inflammatory biomarkers in patients with alcoholic liver disease, particularly examining its role in modulating interleukin-6 (IL-6) levels. Methods: A comprehensive search was performed across PubMed, Embase, and Web of Science to identify randomized controlled trials investigating probiotic interventions in patients with alcoholic liver disease. Seven independent comparisons were chosen for meta-analysis to evaluate probiotics' effects on inflammatory markers, with subgroup analyses examining the impact of region, formulation type, and gender. Results: The findings demonstrated that probiotics led to a significant reduction in IL-6 levels (SMD = -0.68, 95% CI [-1.15; -0.20], p = 0.005). No statistically significant effect of probiotics on interleukin-1β (IL-1β) (SMD = -0.35, 95% CI [-0.87, 0.17], p = 0.18) or tumor necrosis factor alpha (TNF-α) levels (SMD = -0.73, 95% CI [-1.68, 0.21], p = 0.13) was observed. Notably, probiotics were associated with a significant increase in interleukin-10 (IL-10) levels (SMD = 0.93,95% CI [-0.02; 1.87], p = 0.05). Subgroup analyses further revealed that the efficacy of probiotics in reducing IL-6 levels was more pronounced in studies characterized by higher proportions of Asian participants, solid dosage forms, and male subjects. Conclusions: Probiotics have notably reduced IL-6 levels by altering the gut microbiota and increased IL-10 levels, with limited impact on IL-1β and TNF-α. These results suggest probiotics could be used to treat ALD and emphasize the need for personalized probiotic approaches for different populations.