Soy isoflavones, a heterocyclic phenols group, have received considerable attention for their potentially beneficial effects on human health. Compared to glycoside forms, the aglycone isoflavones have higher bioactive potential. The goal of this work was to investigate the capacity of 5 strains of lactic acid bacteria with biotechnological interest to process the glycosylated isoflavones in their more bioavailable aglycones. The concentration of isoflavones were evaluated using HPLC-DAD and the content of total phenolics was evaluated by the Folin-Ciocalteu method. The results demonstrated that the fermentation process with all strains was able to increase the content of bioactive isoflavones and phenolic compounds in soymilk. The cultures of lactic acid bacteria studied in the present work showed a great potential in the metabolism of isoflavones and could be selected for the development of new based-soy foods with enhanced functional and nutritional properties.