Safety and efficacy of a synbiotic formulation containing Akkermansia muciniphila Akk11 on gut microbiota and metabolic health: a randomized controlled trial

Abstract Aim Overweight and obesity are global public health challenges characterized by chronic low-grade inflammation, metabolic dysregulation, and gut microbiota imbalance. This study evaluated the safety and efficacy of a synbiotic formulation containing Akkermansia muciniphila Akk11 on gut microbiota composition, metabolic regulation, and obesity-associated inflammation. Methods A randomized, double-blind, placebo-controlled trial was conducted at Henan University of Technology. Adults aged 18–45 years with overweight or obesity ( n = 110) were randomly assigned (1:1) to receive either a prebiotic placebo (control) or the synbiotic formulation containing A. muciniphila Akk11 (3.0 × 10 10 active fluorescent units [AFU] daily). Over 8 weeks, gut-microbiota composition was profiled by 16 S ribosomal RNA gene sequencing, and serum biomarkers were quantified by enzyme-linked immunosorbent assay. Emotional well-being, sleep quality, and anthropometric measures were also assessed. Results After the 8-week intervention, the Akk11 group showed significant reductions in tumor necrosis factor-α, interleukin-6, and C-reactive protein and a significant increase in interleukin-25 versus baseline (all p < 0.001). Relative to placebo, circulating Glucagon-Like Peptide-1 and Peptide YY (PYY) concentrations were higher ( p < 0.05), and Malondialdehyde levels were lower ( p < 0.01). Akk11 reduced the enrichment of Escherichia coli / Shigella and promoted the enrichment of beneficial genera, indicating a more favorable gut-microbiota structure. Waist-to-hip ratio decreased significantly ( p < 0.05), and significant reductions were observed in both Patient Health Questionnaire-9 and Pittsburgh Sleep Quality Index scores. No significant changes were detected in routine hematology, clinical chemistry, or blood glucose following Akk11 treatment. Conclusion The synbiotic formulation containing A. muciniphila Akk11 was well tolerated and may serve as a safe adjunctive strategy targeting microbiota-immune-metabolic interactions to alleviate obesity-associated metabolic and inflammatory disorders.