Gut Microbiota and Liver Health: Meta-Analysis of

Diseases, including cardiovascular disease, type II diabetes, and metabolic syndrome, are leading causes of morbidity and mortality worldwide. Non-alcoholic fatty liver disease (NAFLD) is commonly associated with these conditions through shared pathophysiological mechanisms such as insulin resistance, chronic inflammation, and dyslipidemia. Emerging evidence suggests that probiotic formulations containing Bifidobacterium species may support cardiometabolic health by modulating gut microbiota composition. This meta-analysis aimed to assess the efficacy of Bifidobacterium-containing probiotic combinations in improving key cardiometabolic parameters, including lipid profiles, blood pressure, glycemic indices, and inflammatory biomarkers among individuals with NAFLD. A systematic literature search was conducted across PubMed, Embase, the Cochrane Library, and Web of Science databases to identify relevant randomized controlled trials (RCTs) published up to December 2024. A total of 24 RCTs involving 1611 participants met the inclusion criteria. The pooled results demonstrated significant reductions in total cholesterol, triglycerides, and low-density lipoprotein cholesterol following probiotic intervention. Improvements were also observed in fasting glucose levels and inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). Although modest improvements were noted in NAFLD severity, the effects on liver injury markers were relatively limited. These findings suggest that Bifidobacterium-based probiotic combinations may provide cardiometabolic benefits, particularly in lipid regulation, glucose metabolism, and inflammatory control. Further large-scale, well-designed RCTs are warranted to validate these results and to determine the most effective probiotic strains, compositions, and treatment durations.