Oral Administration of <i>Clostridium butyricum</i> Alleviates High-Fat Diet-Induced Obesity in Mice by Modulating Gut <i>Akkermansia muciniphila</i> Abundance via Direct Growth Promotion

This study investigated the anti-obesity effects of <i>Clostridium butyricum</i> (CLB) and the underlying mechanisms through gut microbiota modulation. High-fat diet (HFD)-fed C57BL/6 mice were orally administered CLB (1 × 10¹⁰ CFU/kg/day) for 8 weeks. CLB intervention reduced body weight gain by 13.20% and decreased fat mass (21.10 ± 2.24% vs. HFD: 23.39 ± 2.34%, <i>P</i> < 0.05), while partially restoring fecal butyrate levels (11.73 ± 4.99 vs. HFD: 7.27 ± 3.40 μg/g, <i>P</i> < 0.05). 16S rRNA gene sequencing revealed CLB selectively increased the abundance of <i>Akkermansia</i>, which was depleted in HFD mice. <i>In vitro</i>, butyrate, CLB lysate, and culture supernatant significantly enhanced the growth of <i>Akkermansia muciniphila</i> (AKK), indicating microbial cross-feeding. These findings demonstrate CLB alleviates obesity by restoring the abundance of AKK, partly through the production of metabolites that promote the proliferation of AKK, offering novel insights into probiotic-driven microbiota modulation for metabolic health.