Meta-analysis of the effectiveness of fecal microbiota transplantation in the treatment of metabolic-associated fatty liver disease: A systematic review based on liver inflammation indicators and fat content.

FMT significantly reduced alanine aminotransferase (ALT) levels compared to standard care in MASLD patients.

• Mean difference (MD) = -6.81, 95% confidence interval [-10.29, -3.33], P = .0001
• Analysis based on 8 randomized controlled trials selected from PubMed, Cochrane, Embase, and Web of Science (inception to September 2025)
• FMT protocols varied (any protocol) versus standard care comparator

FMT significantly reduced aspartate aminotransferase (AST) levels compared to standard care in MASLD patients.

• Mean difference (MD) = -7.13, 95% confidence interval [-10.45, -3.80], P < .0001
• Risk of bias was assessed using Cochrane ROB 1.0
• Results based on 8 RCTs included in the systematic review and meta-analysis

Subgroup analysis revealed greater ALT improvement in MASLD patients aged under 50 years compared to the overall population.

• MD = -14.00, 95% confidence interval [-22.79, -5.20], P = .002 for patients aged <50 years
• This effect was larger in magnitude than the overall ALT result (MD = -6.81)
• Age was identified as a modulating factor in the ALT response to FMT

FMT markedly decreased proton density fat fraction, a measure of hepatic fat content, in MASLD patients.

• MD = -3.50, 95% confidence interval [-5.12, -1.87], P < .0001
• Proton density fat fraction was used as a key imaging-based outcome for hepatic steatosis
• This finding indicates FMT reduces hepatic fat content in addition to inflammation markers

FMT did not produce a significant change in body mass index (BMI) in MASLD patients.

• MD = -0.69, 95% confidence interval [-1.49, 0.11], P = .09
• The non-significant BMI result contrasted with significant improvements in liver-specific outcomes
• Authors interpret the lack of BMI improvement as suggesting 'localized liver effects rather than systemic metabolic impact'

The meta-analysis included 8 randomized controlled trials identified through a systematic search of four major databases following PRISMA guidelines.

• Databases searched: PubMed, Cochrane, Embase, and Web of Science from inception to September 2025
• Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed
• Outcomes evaluated included ALT, AST, proton density fat fraction, and BMI
• Risk of bias was assessed using Cochrane ROB 1.0

MASLD affects over 25% of the global population and can progress from hepatic steatosis to fibrosis, with gut microbiota dysbiosis via the gut-liver axis identified as a relevant mechanism.

• Current therapies for MASLD show limited efficacy according to the authors
• Gut microbiota dysbiosis via the gut-liver axis is highlighted as the mechanistic rationale for FMT as a novel intervention
• The disease spectrum progresses from hepatic steatosis to fibrosis