Abstract

Obesity, a multifactorial metabolic disorder, has been increasingly linked to gut microbiota dysbiosis and its downstream metabolites. Among these, short-chain fatty acids (SCFAs) and secondary bile acids (SBAs) play pivotal roles in energy regulation, glucose and lipid metabolism, inflammation, and host-microbiota crosstalk. Fermented milk products, enriched with probiotics, prebiotics, and bioactive peptides, offer a dietary intervention capable of modulating the gut microbial community and promoting the production of beneficial metabolites. This narrative review synthesizes evidence from both animal and human studies to explore the influence of fermented milk products on SCFA and SBA production in the context of obesity. Findings suggest that fermented milk consumption enhances the abundance of beneficial bacteria (e.g., Lactobacillus, Bifidobacterium), increases SCFA and SBA levels, improves intestinal barrier function, and contributes to improved metabolic outcomes, including reduced inflammation, improved insulin sensitivity, and favorable lipid profiles. These effects are mediated through key molecular pathways involving free fatty acid receptors, bile acid receptors, and inflammatory mediators. Further long-term, mechanistic, and population-diverse studies are essential to optimize formulations and substantiate clinical applications of fermented milk in obesity management.