Background: Soy isoflavones, an important class of phytoestrogens, are suggested to be
responsible for a number of biological activities associated with health benefits, including defense
against various chronic diseases, including breast and prostate cancer, cardiovascular disorders, and
osteoporosis, and they may alleviate the symptoms of menopause.
Methods: However, current researches (including patents) have shown that the clinical efficacy of
these phenolic compounds is related to the ability of an individual to biotransform isoflavones into
equol, which is a metabolite of daidzein formed exclusively by the intestinal microbiota.
Results: This biologically active metabolite presents greater effects than other isoflavones; however,
only about 30-50 % of people have a microbiota that is able to produce equol from dietary daidzein.
Concern has recently grown about applications to improve the production of this metabolite.
Conclusion: This paper summarizes the metabolism of equol, its production, and clinical