Quantitative assessment of urinary equol levels, equol-producing bacteria, and the faecal microbiota in healthy Japanese individuals
In: Beneficial MicrobesGifu Prefectural Research Institute for Food Science, 1-1 Yanagido, Gifu 501-1112, Japan
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Abstract
Equol (4′,7-isoflavandiol) has attracted considerable attention for its potential efficacy in treating hormonal diseases. In this study we collected samples from healthy Japanese individuals (n = 91) to observe the relationship between the abundance of equol-producing bacteria in their faeces and the concentration of equol in their urine. Quantitative polymerase chain reaction (qPCR) targeting the dihydrodaidzein reductase gene (dhdr) was used to detect equol-producing bacteria. Equol producers, who were defined as individuals with >1000 nmol/l equol in their urine, exhibited 4-8 log10 copies of dhdr/g faeces of equol-producing bacteria. We assessed the accuracy of these findings by determining the rate of correspondence between possessing equol-producing bacteria and producing urinary equol. Of the 91 participants, 33 were found to be positive for both equol-producing bacteria and urinary equol, 52 were negative for both, one was positive for equol-producing bacteria and negative for urinary equol, and five were negative for equol-producing bacteria and positive for urinary equol. The sensitivity and specificity of the qPCR for detecting equol-producing bacteria were 86.8% and 98.1%, respectively. On the whole, the presence of equol-producing bacteria and urinary equol displayed 93.4% concordance, with a kappa coefficient of 0.862. No apparent correlation was observed between dhdr copy number in the faeces and urinary equol concentrations. Analysis of the faecal microbiota showed that alpha diversity indices (OTU, ACE, Chao1, Shannon) were significantly higher in equol producers. Specifically, the relative abundance of phylum Pseudomonadota was increased in non-equol producers, while abundance of genus Alistipes, Barnesiella, Butyricimonas, Odoribacter, and Ruminococcus, which produce short chain fatty acids and/or hydrogen, were only observed in equol producers. These results suggest that a certain amount of equol-producing bacteria must be present in the intestine to produce detectable levels of equol, and that equol productivity might be affected by other components of the microbiota.
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Altaib, H., Nakamura, K., Abe, M., Badr, Y., Yanase, E., Nomura, I. and Suzuki, T., 2021. Differences in the concentration of the faecal neurotransmitters GABA and glutamate are associated with microbial composition among healthy human subjects. Microorganisms 9: 378. https://doi.org/10.3390/microorganisms9020378
-
Atkinson, C., Frankenfeld, L.C. and Lampe, W.J., 2005. Gut bacterial metabolism of the soy isoflavone daidzein: exploring the relevance to human health. Experimental Biology and Medicine 230: 155-170. https://doi.org/10.1177/153537020523000302
-
Braune, A. and Blaut, M., 2017. Evaluation of inter-individual differences in gut bacterial isoflavone bioactivation in humans by PCR-based targeting of genes involved in equol formation. Journal of Applied Microbiology 124: 220-231. https://doi.org/10.1111/jam.13616
-
Danylec, N., Stoll, A.D., Dötsch, A. and Huch, M., 2019. Draft genome sequences of type strains of Gordonibacter faecihominis, Paraeggerthella hongkongensis, Parvibacter caecicola, Slackia equolifaciens, Slackia faecicanis, and Slackia isoflavoniconvertens. Microbiology 8: 2. https://doi.org/10.1128/MRA.01532-18.
-
Decroos, K., Vanhemmens, S., Cattoir, S., Boon, N. and Verstraete, W., 2005. Isolation and characterisation of an equol-producing mixed microbial culture from a human faecal sample and its activity under gastrointestinal conditions. Archives Microbiology 183: 45-55. https://doi.org/10.1007/s00203-004-0747-4
-
Elghali, S., Mustafa, S., Amid, M., Manap, M.Y.A.B.D., Ismail, A. and Abas, F., 2012. Bioconversion of daidzein to equol by Bifidobacterium breve 15700 and Bifidobacterium longum BB536. Journal of Functional Foods 4: 736-745. https://doi.org/10.1016/j.jff.2012.04.013
-
Fan, J., Wang, Y., You, Y., Ai, Z., Dai, W., Piao, C., Liu, J. and Wang, Y., 2019. Fermented ginseng improved alcohol liver injury in association with changes in the gut microbiota of mice. Food and Function 10: 5566-5573. https://doi.org/10.1039/c9fo01415b
-
Fatima, A., Khan, S.M. and Ahmad, M.W., 2020. Therapeutic potential of equol: a comprehensive review. Current Pharmaceutical Design 26: 5837-5843. https://doi.org/10.2174/1381612826999201117122915
-
Franke, A.A., Lai, F.J., Halm, M.B., Pagano, I., Kono, N., Mack, J.W. and Hodis, N.H., 2012a. Equol production changes over time in postmenopausal women. Journal of Nutritional Biochemistry 23: 573-579. https://doi.org/10.1016/j.jnutbio.2011.03.002
-
Franke, A.A., Lai, F.J., Pagano, I., Morimoto, Y. and Maskarinec, G., 2012b. Equol production changes over time in pre-menopausal women. British Journal of Nutrition 107: 1201-1206. https://doi.org/10.1017/S0007114511004223
-
Göker, M., Gronow, S., Zeytun, A., Nolan, M., Lucas, S., Lapidus, A., Hammon, N., Deshpande, S., Cheng, J., Pitluck, S., Liolios, K., Pagani, I., Ivanova, N., Mavromatis, K., Ovchinikova, G., Pati, A., Tapia, R., Han, C., Goodwin, L., Chen, A., Palaniappan, K., Land, M., Hauser, L., Jeffries, D.C., Brambilla, E., Rohde, M., Detter, C.J., Woyke, T., Bristow, J., Markowitz, V., Hugenholtz, P., Eisen, A.J., Kyrpides, C.N. and Klenk, H., 2021. Complete genome sequence of Odoribacter splanchnicus type strain (1651/6T). Standards in Genomic Sciences 4: 200-209. https://doi.org/10.4056/sigs.1714269
-
Guadamuro, L., Dohrmann, B.A., Tebbe, C.C., Mayo, B. and Delgado, S., 2017. Bacterial communities and metabolic activity of faecal cultures from equol producer and non-producer menopausal women under treatment with soy isoflavones. BMC Microbiology 17: 93. https://doi.org/10.1186/s12866-017-1001-y
-
Guadamuro, L., Azcárate-Peril, M.A., Tojo, R., Mayo, B. and Delgado, S., 2019. Use of high throughput amplicon sequencing and ethidium monoazide dye to track microbiota changes in an equol-producing menopausal woman receiving a long-term isoflavones treatment. AIMS Microbiology 5: 102-116. https://doi.org/10.3934/microbiol.2019.1.102
-
Ho, C.S., Chan, G.S., Yi, Q., Wong, E. and Leung, C.P., 2001. Soy intake and the maintenance of peak bone mass in Hong Kong Chinese women. Journal of Bone and Mineral Research 16: 1363-1369. https://doi.org/10.1359/jbmr.2001.16.7.1363.
-
Hughes, L.R., Horn, H.W., Finnegan, P., Newman, W.J., Marco, L.M., Keim, L.N. and Kable, E.M., 2021. Resistant starch type 2 from wheat reduces postprandial glycemic response with concurrent alterations in gut microbiota composition. Nutrients 13: 645. https://doi.org/10.3390/nu13020645
-
Ihaka, R. and Gentleman, R., 1996. R: a language for data analysis and graphics. Journal of Computational and Graphical Statistics 5: 299-314. https://doi.org/10.2307/1390807
-
Iino, C., Shimoyama, T., Iino, K., Yokoyama, Y., Chinda, D., Sakuraba, H., Fukuda, S. and Nakaji, S., 2019. Daidzein intake is associated with equol producing status through an increase in the intestinal bacteria responsible for equol production. Nutrients 11: 433. https://doi.org/10.3390/nu11020433
-
Ikeda, Y., Iki, M., Morita, A., Kajita, E., Kagamimori, S., Kagawa, Y. and Yoneshima, H., 2006. Intake of fermented soybeans, natto, is associated with reduced bone loss in postmenopausal women: Japanese population-based osteoporosis (JPOS) study. Journal of Nutrition 136: 1323-1328. https://doi.org/10.1093/jn/136.5.1323
-
Jin, J., Kitahara, M., Sakamoto, M., Hattori, M. and Benno, Y., 2010. Slackia equolifaciens sp. nov., a human intestinal bacterium capable of producing equol. International Journal of Systematic and Evolutionary Microbiology 60: 1721-1724. https://doi.org/10.1099/ijs.0.016774-0
-
Jin, J., Nishihata, T., Kakiuchi, N. and Hattori, M., 2008. Biotransformation of C-glucosylisoflavone puerarin to estrogenic (3S)-equol in co-culture of two human intestinal bacteria. Biological and Pharmaceutical Bulletin 31: 1621-1625. https://doi.org/10.1248/bpb.31.1621
-
Joannou, G.E., Kelly, G.E., Reeder, A.Y., Waring, M. and Nelson, C., 1995. A urinary profile study of dietary phytoestrogens. The identification and mode of metabolism of new isoflavonoids. Journal of Steroid Biochemistry and Molecular Biology 54: 167-184. https://doi.org/10.1016/0960-0760(95)00131-i
-
Johnson, L.S., Park, Y.H., Vattem, A.D., Grammas, P., Ma, H. and Seeram, P.N., 2020. Equol, a blood-brain barrier permeable gut microbial metabolite of dietary isoflavone daidzein, exhibits neuroprotective effects against neurotoxins induced toxicity in human neuroblastoma SH-SY5Y cells and Caenorhabditis elegans. Plant Foods Human Nutrition 75: 512-517. https://doi.org/10.1007/s11130-020-00840-0
-
Kawada, Y., Yokoyama, S., Yanase, E., Niwa, T. and Suzuki, T., 2016. The production of S-equol from daidzein is associated with a cluster of three genes in Eggerthella sp. YY7918. Bioscience of Microbiota, Food and Health 35: 113-121. https://doi.org/10.12938/bmfh.2015-023
-
Kawada, Y., Goshima, T., Sawamura, R., Yokoyama, S., Yanase, E., Niwa, T., Ebihara, A., Inagaki, M., Yamaguchi, K., Kuwata, K., Kato, Y., Sakurada, O. and Suzuki, T., 2018. Daidzein reductase of Eggerthella sp. YY7918, its octameric subunit structure containing FMN/FAD/4Fe-4S, and its enantioselective production of R-dihydroisoflavones. Journal of Bioscience and Bioengineering 126: 301-309. https://doi.org/10.1016/j.jbiosc.2018.03.018
-
Litvak, Y., Byndloss, X.M., Tsolis, M.R. and Bäumler, J.A., 2017. Dysbiotic Proteobacteria expansion: a microbial signature of epithelial dysfunction. Current Opinion in Microbiology 39: 1-6. https://doi.org/10.1016/j.mib.2017.07.003
-
Maruo, T., Sakamoto, M., Ito, C., Toda, T. and Benno, Y., 2008. Adlercreutzia equolifaciens gen. nov., sp. nov., an equol-producing bacterium isolated from human faeces, and emended description of the genus Eggerthella. International Journal of Systematic and Evolutionary Microbiology 58: 1221-1227. https://doi.org/10.1099/ijs.0.65404-0
-
Matthies, A., Clavel, T., Gütschow, M., Engst, W., Haller, D., Blaut, M. and Braune, A., 2008. Conversion of daidzein and genistein by an anaerobic bacterium newly isolated from the mouse intestine. Applied and Environmental Microbiology 74: 4847-4852. https://doi.org/10.1128/AEM.00555-08
-
Matthies, A., Blaut, M. and Braune, A., 2009. Isolation of a human intestinal bacterium capable of daidzein and genistein conversion. Applied and Environmental Microbiology 75: 1740-1744, https://doi.org/10.1128/AEM.01795-08
-
Mayo, B., Vázquez, L. and Flórez, B.A., 2019. Equol: a bacterial metabolite from the daidzein isoflavone and its presumed beneficial health effects. Nutrients 11: 2231. https://doi.org/10.3390/nu11092231
-
Minamida, K., Tanaka, M., Abe, A., Sone, T., Tomita, F., Hara, H. and Asano, K., 2006. Production of equol from daidzein by gram-positive rod-shaped bacterium isolated from rat intestine. Journal of Bioscience and Bioengineering 102: 247-250. https://doi.org/10.1263/jbb.102.247
-
Mistry, H.R., Borewicz, K., Gu, F., Verkade, J.H., Schols, A.H., Smidt, H. and Tietge, J.F.U., 2020. Dietary isomalto/malto-polysaccharides increase faecal bulk and microbial fermentation in mice. Molecular Nutrition Food Research 64: 2000251. https://doi.org/10.1002/mnfr.202000251
-
Morotomi, M., Nagai, F., Sakon, H. and Tanaka, R., 2008. Dialister succinatiphilus sp. nov. and Barnesiella intestinihominis sp. nov., isolated from human faeces. International Journal of Systematic and Evolutionary Microbiology 58: 2716-2720. https://doi.org/10.1099/ijs.0.2008/000810-0
-
Nagata, C., Mizoue, T., Tanaka, K., Tsuji, I., Tamakoshi, A., Matsuo, K., Wakai, K., Inoue, M., Tsugane, S. and Sakazaki, S., 2014. Soy intake and breast cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population. Japanese Journal of Clinical Oncology 44: 282-295. https://doi.org/10.1093/jjco/hyt203
-
Parker, J.B., Wearsch, A.P., Veloo, C.M.A. and Rodriguez-Palacios, A., 2020. The genus Alistipes: gut bacteria with emerging implications to inflammation, cancer, and mental health. Frontiers in Immunology 11: 906. https://doi.org/10.3389/fimmu.2020.00906
-
Redruello, B., Guadamuro, L., Cuesta, I., Álvarez-Buylla, R.J., Mayo, B. and Delgado, S., 2015. A novel UHPLC method for the rapid and simultaneous determination of daidzein, genistein and equol in human urine. Journal of Chromatography B 1005: 1-8. https://doi.org/10.1016/j.jchromb.2015.09.029
-
Reinwald, S. and Weaver, M.C., 2010. Soy components vs. whole soy: are we betting our bones on a long shot? Journal of Nutrition 140: 2312S-2317S. https://doi.org/10.3945/jn.110.124008
-
Rowland, I.R., Wiseman, H., Sanders, A.T., Adlercreutz, H. and Bowey, A.E., 2000. Interindividual variation in metabolism of soy isoflavones and lignans: influence of habitual diet on equol production by the gut microflora. Nutrition and Cancer 36: 27-32. https://doi.org/10.1207/S15327914NC3601_5
-
Sánchez-Pellicer, P., Navarro-López, V., Gonzáles-Tamayo, R., Llopis-Ruiz, C., Núñez-Delegido, E., Ruzafa-Costas, B., Navarro-Moratalla, L. and Agüera-Santos, J., 2021. Descriptive study of gut microbiota in infected and colonized subjects by Clostridiodes difficile. Microorganisms 9: 1727. https://doi.org/10.3390/microorganisms9081727
-
Schloss, D.P., Westcott, L.S., Ryabin, T., Hall, R.J., Hartmann, M., Hollister, B.E., Lesniewski, A.R., Oakley, B.B., Parks, H.D., Robinson, J.C., Sahl, W.J., Stres, B., Thallinger, G.G., Van Horn, J.D. and Weber, F.C., 2009. Introducing mothur: open-source, platform-independent, community-supported software for describing and comparing microbial communities. Applied and Environmental Microbiology 75: 7537-7541. https://doi.org/10.1128/AEM.01541-09
-
Setchell, D.R.K., Brown, M.N. and Lydeking-Olsen, E., 2002. The clinical importance of the metabolite equol – a clue to the effectiveness of soy and its isoflavones. Journal of Nutrition 132: 3577-3584. https://doi.org/10.1093/jn/132.12.3577
-
Setchell, D.R.K., Faughnan, S.M., Avades, T., Zimmer-Nechemias, L., Brown, M.N., Wolfe, E.B., Brashear, T.W., Desai, P., Oldfield, F.M., Botting, P.N. and Cassidy, A., 2003. Comparing the pharmacokinetics of daidzein and genistein with the use of 13C-labeled tracers in premenopausal women. American Journal of Clinical Nutrition 77: 411-419. https://doi.org/10.1093/ajcn/77.2.411
-
Setchell, D.R.K. and Cole, J.S., 2006. Method of defining equol-producer status and its frequency among vegetarians. Journal of Nutrition 136: 2188-2193. https://doi.org/10.1093/jn/136.8.2188
-
Setchell, D.R.K. and Clerici, C., 2010. Equol: history, chemistry, and formation. Journal of Nutrition 140: 1355S-1362S. https://doi.org/10.3945/jn.109.119776.
-
Simpson, L.H. and Campbell, J.B., 2015. Review article: dietary fibre-microbiota interactions. Alimentary Pharmacology and Therapeutics 42: 158-179. https://doi.org/10.1111/apt.13248
-
Takahashi, A., Kokubun, M., Anzai, Y., Kogre, A., Ogata, T., Imaizumi, H., Fujita, M., Hayashi, M., Abe, K. and Ohira, H., 2022. Association between equol production and metabolic syndrome in Japanese women in their 50s-60s. Menopause 29: 1196-1199. https://doi.org/10.1097/GME.0000000000002052.
-
Takeda, T., Ueno, T., Uchiyama, S., Hiramatsu, K. and Shiina, M., 2016. Relation between premenstrual syndrome and equol-production status. Journal of Obstetrics and Gynaecology Research 42: 1575-1580. https://doi.org/10.1111/jog.13073
-
Tanaka, M., Fujii, S., Inoue, H., Takahashi, N., Ishimi, Y. and Uehara, M., 2022. (S)-equol is more effective than (R)-equol inhibiting osteoclast formation and enhancing osteoclast apoptosis, and reduces estrogen deficiency-induced bone loss in mice. Journal of Nutrition 152: 1831-1842. https://doi.org/10.1093/jn/nxac130.
-
Tanihiro, R., Sakano, K., Oba, S., Nakamura, C., Ohki, K., Hirota, T., Sugiyama, H., Ebihara, S. and Nakamura, Y., 2020. Effects of yeast mannan which promotes beneficial Bacteroides on the intestinal environment and skin condition: a randomized, double-blind, placebo-controlled study. Nutrients 12: 3673. https://doi.org/10.3390/nu12123673
-
Toh, H., Ohshima, K., Suzuki, T., Hattori, M. and Morita, H., 2013. Complete genome sequence of the equol-producing bacterium Adlercreutzia equolifaciens DSM 19450T. Genome Announcements 1: 10. https://doi.org/10.1128/genomeA.00742-13
-
Tousen, Y., Ishiwata, H., Ishimi, Y. and Ikegami, S., 2015. Equol, a metabolite of daidzein, is more efficient than daidzein for bone formation in growing female rats. Phytotherapy Research 29: 1349-1354. https://doi.org/10.1002/ptr.5387
-
Tsuji, H., Moriyama, K., Nomoto, K., Miyanaga, N. and Akaza, H., 2010. Isolation and characterization of the equol-producing bacterium Slackia sp. strain NATTUS. Archives of Microbiology 192: 279-287. https://doi.org/10.1007/s00203-010-0546-z
-
Uchiyama, S., Ueno, T. and Suzuki, T., 2007. Identification of a newly isolated equol-producing lactic acid bacterium from the human faeces. Journal of Intestinal Microbiology 21: 217-220.
-
Ueno, T., Abiru, Y., Uchiyama, S. and Ishimi, Y., 2014. Distribution of 24-h urinary equol excretion as an indicator of the physiological range in healthy Japanese equol excretors. Journal of Functional Foods 7: 129-135. https://doi.org/10.1016/j.jff.2013.12.012
-
Vázquez, L., Guadamuro, L., Giganto, F., Mayo, B. and Flórez, B.A., 2017. Development and use of a real-time quantitative PCR method for detecting and quantifying equol-producing bacteria in human faecal samples and slurry cultures. Frontiers in Microbiology 8: 1155. https://doi.org/10.3389/fmicb.2017.01155
-
Vázquez, L., Flórez, B.A., Redruello, B. and Mayo, B., 2020. Metabolism of soy isoflavones by intestinal bacteria: genome analysis of an Adlercreutzia equolifaciens strain that does not produce equol. Biomolecules 10: 950. https://doi.org/10.3390/biom10060950
-
Wang, X., Hur, H., Lee, H.J., Kim, T.K. and Kim, S., 2005. Enantioselective synthesis of S-equol from dihydrodaidzein by a newly isolated anaerobic human intestinal bacterium. Applied and Environmental Microbiology 71: 214-219, https://doi.org/10.1128/AEM.71.1.214-219.2005
-
Waters, L.J. and Ley, E.R., 2019. The human gut bacteria Christensenellaceae are widespread, heritable, and associated with health. BMC Biology 17: 83. https://doi.org/10.1186/s12915-019-0699-4
-
Wong, M.V.J., Kendall, W.C.C., Marchie, A., Liu, Z., Vidgen, Ed., Holmes, C., Jackson, C., Josse, G.R., Pencharz, B.P., Rao, V.A., Vuksan, V., Singer, W. and Jenkins, J.D., 2012. Equol status and blood lipid profile in hyperlipidemia after consumption of diets containing soy foods. American Journal of Clinical Nutrition 95: 564-571. https://doi.org/10.3945/ajcn.111.017418.
-
Wu, Z., Sang, L.-X. and Chang, B., 2020. Isoflavones and inflammatory bowel disease. World Journal of Clinical Cases 8: 2081-2091. https://doi.org/10.12998/wjcc.v8.i11.2081
-
Xu, Z., Xu, J., Li, S., Cui, H., Zhang, G., Ni, X. and Wang, J., 2022. S-equol enhances osteoblastic bone formation and prevents bone loss through OPG/RANKL via the PI3K/Akt pathway in streptozotocin-induced diabetic rats. Frontiers in Nutrition 9: 986192. https://doi.org/10.3389/fnut.2022.986192
-
Yokoyama, S. and Suzuki, T., 2008. Isolation and characterization of a novel equol-producing bacterium from human faeces. Bioscience, Biotechnology, and Biochemistry 72: 2660-2666. https://doi.org/10.1271/bbb.80329
-
Yokoyama, S., Oshima, K., Nomura, I., Hattori, M. and Suzuki, T., 2011. Complete genomic sequence of the equol-producing bacterium Eggerthella sp. Strain YY7918, isolated from adult human intestine. Journal of Bacteriology 193: 5570-5571. https://doi.org/10.1128/JB.05626-11
-
Yoshioka, H., Watanabe, M., Nanba, F., Suzuki, T., Fukiya, S., Yokota, A. and Toda, T., 2020. Administration of cholic acid inhibits equol production from daidzein in mice. Journal of Nutritional Science and Vitaminology 66: 571-576. https://doi.org/10.3177/jnsv.66.571
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Quantitative assessment of urinary equol levels, equol-producing bacteria, and the faecal microbiota in healthy Japanese individuals
In: Beneficial MicrobesGifu Prefectural Research Institute for Food Science, 1-1 Yanagido, Gifu 501-1112, Japan
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Abstract
Equol (4′,7-isoflavandiol) has attracted considerable attention for its potential efficacy in treating hormonal diseases. In this study we collected samples from healthy Japanese individuals (n = 91) to observe the relationship between the abundance of equol-producing bacteria in their faeces and the concentration of equol in their urine. Quantitative polymerase chain reaction (qPCR) targeting the dihydrodaidzein reductase gene (dhdr) was used to detect equol-producing bacteria. Equol producers, who were defined as individuals with >1000 nmol/l equol in their urine, exhibited 4-8 log10 copies of dhdr/g faeces of equol-producing bacteria. We assessed the accuracy of these findings by determining the rate of correspondence between possessing equol-producing bacteria and producing urinary equol. Of the 91 participants, 33 were found to be positive for both equol-producing bacteria and urinary equol, 52 were negative for both, one was positive for equol-producing bacteria and negative for urinary equol, and five were negative for equol-producing bacteria and positive for urinary equol. The sensitivity and specificity of the qPCR for detecting equol-producing bacteria were 86.8% and 98.1%, respectively. On the whole, the presence of equol-producing bacteria and urinary equol displayed 93.4% concordance, with a kappa coefficient of 0.862. No apparent correlation was observed between dhdr copy number in the faeces and urinary equol concentrations. Analysis of the faecal microbiota showed that alpha diversity indices (OTU, ACE, Chao1, Shannon) were significantly higher in equol producers. Specifically, the relative abundance of phylum Pseudomonadota was increased in non-equol producers, while abundance of genus Alistipes, Barnesiella, Butyricimonas, Odoribacter, and Ruminococcus, which produce short chain fatty acids and/or hydrogen, were only observed in equol producers. These results suggest that a certain amount of equol-producing bacteria must be present in the intestine to produce detectable levels of equol, and that equol productivity might be affected by other components of the microbiota.
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