Carbohydrate-active Enzymes-rich Probiotics <em>Bifidobacterium adolescentis</em> CCFM1173 Alleviate Long-Term High-Fat Diet Induced Obesity in Mice by Modulating Cecal and Colonic Microbiota and Metabolites

Obesity is a global health issue characterized by gut microbiota dysbiosis and lipid accumulation. Probiotics have garnered considerable attention due to their health benefits. This study aims to evaluate the effects of five species of probiotics (six strains) on modulating gut microbiota composition to alleviate obesity in long-term high-fat diet (HFD)-induced obese mice. To establish the obese mouse model, HFD was administered for ten weeks, followed by nineteen weeks of probiotic treatment to assess the anti-obesity effects. The twenty-nine weeks of HFD treatment induced weight gain, affected serum factors, and altered cecal and colonic microbiota and colonic short-chain fatty acids (SCFAs). Notably, strain <em>Bifidobacterium adolescentis</em> CCFM1173 demonstrated significant anti-obesity effects, reducing final weight gain and modulating serum factors such as AST, ALT, and TC. Probiotic treatments induced distinct changes in cecal microbiota composition and structure, with similar alterations observed at the phylum level in colonic microorganisms but not at the genus level. Furthermore, <em>B. adolescentis</em> CCFM1173 uniquely promoted anti-obesity effects by increasing the abundance of <em>Akkermansia</em> in the colon by 160-fold, which subsequently stimulated butyric acid production from 7.17 to 11.95 mmol/kg. Genomic analysis of probiotics for carbohydrate-active enzymes (CAZymes) indicated that the content of colonic SCFAs increased with the upregulation of CAZymes in the genera <em>Lactobacillus</em> and <em>Bifidobacterium</em>. In conclusion, this study suggests that<em> B. adolescentis</em> CCFM1173 treatment could be a potential strategy to alleviate obesity. It also implies that administering CAZymes-rich probiotics might be more effective in improving colonic SCFAs levels to alleviate associated diseases.