A multispecies Lactobacillus- and Bifidobacterium-containing probiotic mixture significantly reduced the adverse metabolic and inflammatory effects of a 14-week high-fat diet in wild-type C57/BL6J mice gavaged 5 days a week with the probiotic mixture or vehicle. Recent evidence indicates that the gut microbiome may play a decisive role in the onset of obesity and associated chronic metabolic diseases, such as type 2 diabetes, by modulating nutrient absorption and factors conducive to development of a persistent low-grade inflammatory state. By modifying the gut microbiome, probiotics might constitute an effective dietary strategy for managing these metabolic disorders. The tested probiotic mixture significantly attenuated the increase in body weight, serum glucose concentration and insulin resistance induced by the high-fat diet. Furthermore, it significantly reduced the up-regulation of expression of several genes encoding pro-inflammatory adipokines and leukotriene pathway enzymes (CCL-2, IL-6 and leukotriene C4 synthase in adipose tissue, leukotriene C4 synthase and leukotriene A4 hydrolase in the gut). It also significantly counteracted the down-regulation of adipose tissue gene expression related to the anti-inflammatory adipokine adiponectin in mice fed the high-fat diet. These results suggest that the mechanism underlying the beneficial metabolic effects of the probiotic mixture might involve inhibition of gut and adipose tissue inflammation.