The increasing prevalence of metabolic syndrome-related diseases, such as obesity and
type-2 diabetes, makes urgent to develop alternative therapies to prevent or reduce the progression of these pathologies. On the other hand, during the last years it has been demonstrated the important role that gut microbiota plays on human health, and the influence that alterations in this bacterial balance plays in the development of metabolic diseases. Thus, different bacterial strains have emerged as potential probiotics for the prevention of the complications characteristic of obesity, such as the excess of adiposity or the dysregulation of glycemia. In this study, we have used Caenorhabditis elegans (C. elegans) as a model to examine the potential probiotic activities of the bacterium Pediococcus acidilactici (PA) CECT9879, together with the underlying mechanisms of action. Our work revealed that the treatment with PA reduced the fat accumulation of C. elegans in a 9% when grown in NGM medium, and a 16% in a glucose-loaded (10 mM) NGM medium, quantified by Nile Red staining, without affecting the development of the worm. The reduced fat content was also accompanied by an extension of the nematode median survival of two days in comparison with untreated control worms. Subsequent gene expression analyses demonstrated that the probiotic activities were mediated by modulation of the insulin/IGF-1 signaling (IIS) pathway through the overexpression of
daf-16 and
ins-6 mediators, but also by an increased expression of genes involved in the fatty acid peroxisomal beta-oxidation. Taken together, our data suggest that PA CECT9879 could be considered a potential probiotic strain for the prevention of the metabolic syndrome-related disturbances, and highlight the use of C. elegans as an appropriate in vivo model for the study of the mechanisms underlying these diseases.