Belobrajdic DP, James-Martin G, Jones D, Tran CD. Soy and gastrointestinal health: a review. Nutrients. 2023; 15.

Chen LR, Chen KH. Utilization of isoflavones in soybeans for women with menopausal syndrome: an overview. Int J Mol Sci. 2021; 22.

Kim IS, Kim CH, Yang WS. Physiologically active molecules and functional properties of soybeans in human health-a current perspective. Int J Mol Sci. 2021; 22.

Nakai S, Fujita M, Kamei Y. Health promotion effects of soy isoflavones. J Nutr Sci Vitaminol (Tokyo). 2020;66:502–7.

Article  CAS  PubMed  Google Scholar 

Zhang X, Veliky CV, Birru RL, Barinas-Mitchell E, Magnani JW, Sekikawa A. Potential protective effects of equol (soy isoflavone metabolite) on coronary heart diseases-from molecular mechanisms to studies in humans. Nutrients. 2021; 13.

Yamamoto S, Sobue T, Kobayashi M, Sasaki S, Tsugane S. Soy, isoflavones, and breast cancer risk in Japan. J Natl Cancer Inst. 2003;95:906–13.

Article  CAS  PubMed  Google Scholar 

Cicero A, Allkanjari O, Busetto GM, Cai T, Largana G, Magri V et al. Nutraceutical treatment and prevention of benign prostatic hyperplasia and prostate cancer. Arch Ital Urol Androl. 2019; 91.

Akhlaghi M, Ghasemi NM, Riasatian M, Sadeghi F. Soy isoflavones prevent bone resorption and loss, a systematic review and meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr. 2020;60:2327–41.

Article  CAS  PubMed  Google Scholar 

Rizzo J, Min M, Adnan S, Afzal N, Maloh J, Chambers CJ et al. Soy protein containing isoflavones improves facial signs of photoaging and skin hydration in postmenopausal women: results of a prospective randomized double-blind controlled trial. Nutrients. 2023; 15.

Canivenc-Lavier MC, Bennetau-Pelissero C. Phytoestrogens and health effects. Nutrients. 2023; 15.

Setchell KD, Zimmer-Nechemias L, Cai J, Heubi JE. Isoflavone content of infant formulas and the metabolic fate of these phytoestrogens in early life. Am J Clin Nutr. 1998;68:S1453–61.

Article  Google Scholar 

Lethaby A, Marjoribanks J, Kronenberg F, Roberts H, Eden J, Brown J. Phytoestrogens for menopausal vasomotor symptoms. Cochrane Database Syst Rev. 2013; 2013: CD001395.

Krizova L, Dadakova K, Kasparovska J, Kasparovsky T, Isoflavones. Molecules. 2019;24. https://doi.org/10.3390/molecules24061076.

Murphy PA, Barua K, Hauck CC. Solvent extraction selection in the determination of isoflavones in soy foods. J Chromatogr B Analyt Technol Biomed Life Sci. 2002;777:129–38.

Article  CAS  PubMed  Google Scholar 

Izumi T, Piskula MK, Osawa S, Obata A, Tobe K, Saito M, et al. Soy isoflavone aglycones are absorbed faster and in higher amounts than their glucosides in humans. J Nutr. 2000;130:1695–9.

Article  CAS  PubMed  Google Scholar 

Mayo B, Vazquez L, Florez AB. Equol: a bacterial metabolite from the daidzein isoflavone and its presumed beneficial health effects. Nutrients. 2019; 11.

Fatima A, Khan MS, Ahmad MW. Therapeutic potential of equol: a comprehensive review. Curr Pharm Des. 2020;26:5837–43.

Article  CAS  PubMed  Google Scholar 

Ni X, Wu B, Li S, Zhu W, Xu Z, Zhang G, et al. Equol exerts a protective effect on postmenopausal osteoporosis by upregulating opg/rankl pathway. Phytomedicine. 2023;108:154509.

Article  CAS  PubMed  Google Scholar 

Choi EJ, Ahn WS, Bae SM. Equol induces apoptosis through cytochrome c-mediated caspases cascade in human breast cancer mda-mb-453 cells. Chem Biol Interact. 2009;177:7–11.

Article  CAS  PubMed  Google Scholar 

Lu Z, Zhou R, Kong Y, Wang J, Xia W, Guo J, et al. S-equol, a secondary metabolite of natural anticancer isoflavone daidzein, inhibits prostate cancer growth in vitro and in vivo, though activating the akt/foxo3a pathway. Curr Cancer Drug Targets. 2016;16:455–65.

Article  CAS  PubMed  Google Scholar 

Jia M, Dahlman-Wright K, Gustafsson JA. Estrogen receptor alpha and beta in health and disease. Best Pract Res Clin Endocrinol Metab. 2015;29:557–68.

Article  CAS  PubMed  Google Scholar 

Fox EM, Davis RJ, Shupnik MA. Erbeta in breast cancer–onlooker, passive player, or active protector? Steroids. 2008;73:1039–51.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Guillette TC, Jackson TW, Belcher SM. Duality of estrogen receptor beta action in cancer progression. Curr Opin Pharmacol. 2018;41:66–73.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Leygue E, Murphy LC. A bi-faceted role of estrogen receptor beta in breast cancer. Endocr Relat Cancer. 2013;20:R127–39.

Article  CAS  PubMed  Google Scholar 

Lund TD, Munson DJ, Haldy ME, Setchell KD, Lephart ED, Handa RJ. Equol is a novel anti-androgen that inhibits prostate growth and hormone feedback. Biol Reprod. 2004;70:1188–95.

Article  CAS  PubMed  Google Scholar 

Harris IS, DeNicola GM. The complex interplay between antioxidants and ros in cancer. Trends Cell Biol. 2020;30:440–51.

Article  CAS  PubMed  Google Scholar 

Choi EJ. Evaluation of equol function on anti- or prooxidant status in vivo. J Food Sci. 2009;74:H65–71.

Article  CAS  PubMed  Google Scholar 

Wei XJ, Wu J, Ni YD, Lu LZ, Zhao RQ. Antioxidant effect of a phytoestrogen equol on cultured muscle cells of embryonic broilers. Vitro Cell Dev Biol Anim. 2011;47:735–41.

Article  CAS  Google Scholar 

Watanabe A, Muraki K, Tamaoki J, Kobayashi M. Soy-derived equol induces antioxidant activity in zebrafish in an nrf2-independent manner. Int J Mol Sci. 2022; 23.

Kang NJ, Lee KW, Rogozin EA, Cho YY, Heo YS, Bode AM, et al. Equol, a metabolite of the soybean isoflavone daidzein, inhibits neoplastic cell transformation by targeting the mek/erk/p90rsk/activator protein-1 pathway. J Biol Chem. 2007;282:32856–66.

Article  CAS  PubMed  Google Scholar 

Setchell KD, Clerici C. Equol: history, chemistry, and formation. J Nutr. 2010;140:S1355–62.

Article  Google Scholar 

Setchell KD, Clerici C, Lephart ED, Cole SJ, Heenan C, Castellani D, et al. S-equol, a potent ligand for estrogen receptor beta, is the exclusive enantiomeric form of the soy isoflavone metabolite produced by human intestinal bacterial flora. Am J Clin Nutr. 2005;81:1072–9.

Article  CAS  PubMed  Google Scholar 

Muthyala RS, Ju YH, Sheng S, Williams LD, Doerge DR, Katzenellenbogen BS, et al. Equol, a natural estrogenic metabolite from soy isoflavones: convenient preparation and resolution of r- and s-equols and their differing binding and biological activity through estrogen receptors alpha and beta. Bioorg Med Chem. 2004;12:1559–67.

Article  CAS  PubMed  Google Scholar 

Duda-Chodak A, Tarko T, Satora P, Sroka P. Interaction of dietary compounds, especially polyphenols, with the intestinal microbiota: a review. Eur J Nutr. 2015;54:325–41.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Shimada Y, Yasuda S, Takahashi M, Hayashi T, Miyazawa N, Sato I, et al. Cloning and expression of a novel nadp(h)-dependent daidzein reductase, an enzyme involved in the metabolism of daidzein, from equol-producing lactococcus strain 20–92. Appl Environ Microbiol. 2010;76:5892–901.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Shimada Y, Takahashi M, Miyazawa N, Abiru Y, Uchiyama S, Hishigaki H. Identification of a novel dihydrodaidzein racemase essential for biosynthesis of equol from daidzein in lactococcus sp. Strain 20–92. Appl Environ Microbiol. 2012;78:4902–7.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Soukup ST, Stoll DA, Danylec N, Schoepf A, Kulling SE, Huch M. Metabolism of daidzein and genistein by gut bacteria of the class coriobacteriia. Foods. 2021; 10.

Setchell KD, Faughnan MS, Avades T, Zimmer-Nechemias L, Brown NM, Wolfe BE, et al. Comparing the pharmacokinetics of daidzein and genistein with the use of 13c-labeled tracers in premenopausal women. Am J Clin Nutr. 2003;77:411–9.

Article  CAS  PubMed  Google Scholar 

Rafii F. The role of colonic bacteria in the metabolism of the natural isoflavone daidzin to equol. Metabolites. 2015;5:56–73.

Article  PubMed  PubMed Central  Google Scholar 

Bolca S, Possemiers S, Herregat A, Huybrechts I, Heyerick A, De Vriese S, et al. Microbial and dietary factors are associated with the equol producer phenotype in healthy postmenopausal women. J Nutr. 2007;137:2242–6.

Article  CAS  PubMed  Google Scholar