The role of gut microbiota augmentation in managing non-alcoholic fatty liver disease: an in-depth umbrella review of meta-analyses with grade assessment

Abstract

Background and aim: Currently, there are no authorized medications specifically for non-alcoholic fatty liver disease (NAFLD) treatment. Studies indicate that changes in gut microbiota can disturb intestinal balance and impair the immune system and metabolism, thereby elevating the risk of developing and exacerbating NAFLD. Despite some debate, the potential benefits of microbial therapies in managing NAFLD have been shown. Methods: A systematic search was undertaken to identify meta-analyses of randomized controlled trials that explored the effects of microbial therapy on the NAFLD population. The goal was to synthesize the existing evidence-based knowledge in this field. Results: The results revealed that probiotics played a significant role in various aspects, including a reduction in liver stiffness (MD: −0.38, 95% CI: [−0.49, −0.26]), hepatic steatosis (OR: 4.87, 95% CI: [1.85, 12.79]), decrease in body mass index (MD: −1.46, 95% CI: [−2.43, −0.48]), diminished waist circumference (MD: −1.81, 95% CI: [−3.18, −0.43]), lowered alanine aminotransferase levels (MD: −13.40, 95% CI: [−17.02, −9.77]), decreased aspartate aminotransferase levels (MD: −13.54, 95% CI: [−17.85, −9.22]), lowered total cholesterol levels (MD: −15.38, 95% CI: [−26.49, −4.26]), decreased fasting plasma glucose levels (MD: −4.98, 95% CI: [−9.94, −0.01]), reduced fasting insulin (MD: −1.32, 95% CI: [−2.42, −0.21]), and a decline in homeostatic model assessment of insulin resistance (MD: −0.42, 95% CI: [−0.72, −0.11]) (P<0.05). Conclusion: Overall, the results demonstrated that gut microbiota interventions could ameliorate a wide range of indicators including glycemic profile, dyslipidemia, anthropometric indices, and liver injury, allowing them to be considered a promising treatment strategy.