Probiotic Strain <i>Bifidobacterium animalis</i> subsp. <i>lactis</i> CECT 8145 Reduces Fat Content and Modulates Lipid Metabolism and Antioxidant Response in <i>Caenorhabditis elegans</i>

Recently, microbial changes in the human gut have been proposed as a possible cause of obesity. Therefore, modulation of microbiota through probiotic supplements is of great interest to support obesity therapeutics. The present study examines the functional effect and metabolic targets of a bacterial strain, <i>Bifidobacterium animalis</i> subsp. <i>lactis</i> CECT 8145, selected from a screening in <i>Caenorhabditis elegans</i>. This strain significantly reduced total lipids (40.5% ± 2.4) and triglycerides (27.6% ± 0.5), exerting antioxidant effects in the nematode (30% ± 2.8 increase in survival vs control); activities were also preserved in a final food matrix (milk). Furthermore, transcriptomic and metabolomic analyses in nematodes fed with strain CECT 8145 revealed modulation of the energy and lipid metabolism, as well as the tryptophan metabolism (satiety), as the main metabolic targets of the probiotic. In conclusion, our study describes for the first time a new <i>B. animalis</i> subsp. <i>lactis</i> strain, CECT 8145, as a promising probiotic for obesity disorders. Furthermore, the data support future studies in obesity murine models