Background: Obesity is closely related to dysbiosis. Probiotics may improve metabolism and alleviate inflammation by regulating microbial–host interaction. Methods: Obesity was induced in rats by feeding a high-fat diet, followed by gavage administration of varying doses of BC99 as an intervention. Results: BC99 significantly reduced body weight gain, improved lipid profiles, alleviated systemic inflammation, and enhanced gut barrier integrity. 16S rRNA sequencing revealed that BC99 increased the abundance of beneficial bacteria, including Bacillota, Akkermansia, and Roseburia. Untargeted metabolomics showed that BC99 upregulated anti-inflammatory lysophosphatidylcholines (LysoPCs) and modulated conjugated bile acids (GUDCA, GDCA), which were correlated with enriched bile salt hydrolase (BSH)-active bacteria (e.g., Lachnoclostridium). Conclusions: The results indicate that W. coagulans BC99 effectively reduces weight gain in rats made obese by a high-fat diet and improves metabolic disorders. These effects are associated with remodeling of the gut microbiota and modulation of key metabolites, supporting a potential ‘microbiota–metabolite–host’ axis in rats that warrants further causal validation.
Pan et al. (Mon,) studied this question.