Latilactobacillus sakei CNTA 173 Reduces Fat Mass by Modulating Sphingolipid Metabolism in Diet-Induced Obese Wistar Rats

The use of probiotics with health-promoting activities has emerged as a strategy to combat specific hallmarks of obesity, such as excessive fat accumulation and associated inflammation. Here, we investigate the physiological and metabolic effects of Latilactobacillus sakei CNTA 173 (10⁹ CFU/day) in diet-induced obese Wistar rats. Biochemical, 16S microbiota, untargeted metabolomic, and gene expression analyses were performed, as well as an in vivo toxicological study to demonstrate its safety. Probiotic-supplemented rats showed reduced adiposity, an improved inflammatory marker profile, and enhanced glucose tolerance, partly by modulating fecal microbiota composition and regulating the production of novel plasma metabolites, specifically sphingolipid-derived mediators such as ceramides. Moreover, no adverse effects were observed in an in vivo toxicity evaluation of this strain in Wistar rats. Our results unveil the fat-reducing and anti-inflammatory effects of L. sakei CNTA 173 and point out the potential use of this probiotic for the prevention of obesity-related disturbances.