[Research development on relation between equol and soy foods health effect]

Under the function of human intestinal bacteria, soybean can produce equol and O-desmethylangolensin. Among humans, 30%-55% have the bacteria capable of producing equol. Factors that influence the capacity to produce equol are not clearly established; however, gut physiology, host genetics, and diet factors are probably related to the individual difference of equol producing. Some studies on high soy-consuming populations reported an inverse association between urinary and serum equol concentrations and breast and prostate cancer risk. Furthermore, several studies of soy supplementation and bone density suggest that soy products may be more effective in maintaining bone density in equol-producing individuals. It requires further identification of the factors influencing the equol producing and the relationship between equol and human health.