Compositional and functional differences in human gut microbiome with respect to equol production and its association with blood lipid level: a cross-sectional study

Wei Zheng; Yue Ma; Ai Zhao; Tingchao He; Na Lyu; Ziqi Pan; Geqi Mao; Yan Liu; Jing Li; Peiyu Wang; Jun Wang; Baoli Zhu; Yumei Zhang

doi:10.1186/s13099-019-0297-6

Compositional and functional differences in human gut microbiome with respect to equol production and its association with blood lipid level: a cross-sectional study

Gut Pathog. 2019 May 10:11:20. doi: 10.1186/s13099-019-0297-6. eCollection 2019.

Authors

Wei Zheng^#^{1

2}, Yue Ma^#^{3

4

5}, Ai Zhao², Tingchao He⁶, Na Lyu^{3

5}, Ziqi Pan⁶, Geqi Mao⁶, Yan Liu⁶, Jing Li^{3

5}, Peiyu Wang², Jun Wang³, Baoli Zhu^{3

4

5

7

8}, Yumei Zhang^{6

9}

Affiliations

¹ 1Division of Endocrinology and Metabolism, Department of Obstetrics, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China.
² 2Department of Social Medicine and Health Education, School of Public Health, Peking University Health Science Center, Beijing, China.
³ 3CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Science, Beichen West Road 1, Haidian District, Beijing, 100101 China.
⁴ 4University of Chinese Academy of Science, Beijing, China.
⁵ Beijing Key Laboratory of Microbial Drug Resistance and Resistome, Beijing, China.
⁶ 6Department of Nutrition and Food Hygiene, School of Public Health, Peking University Health Science Center, Xueyuan Road 38, Haidian District, Beijing, 100191 China.
⁷ 7Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
⁸ 8Department of Pathogenic Biology, School of Basic Medical Sciences, Southwest Medical University, Zhongshan Road, Luzhou, Sichuan China.
⁹ Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, China.

^# Contributed equally.

Abstract

Background: Gut microbiota affects lipid metabolism interactively with diet. Equol, a metabolite of isoflavones produced by gut bacteria, may contribute substantially in beneficial lipid-lowering effects. This study aimed to examine equol production-related gut microbiota differences among humans and its consequent association with blood lipid levels.

Results: Characterization of the gut microbiota by deep shotgun sequencing and serum lipid profiles were compared between equol producers and non-producers. Gut microbiota differed significantly at the community level between equol producers and non-producers (P = 0.0062). At the individual level, 32 species associated with equol production were identified. Previously reported equol-producing related species Adlercreutzia equolifaciens and Bifidobacterium bifidum showed relatively higher abundance in this study in equol producers compared to non-producers (77.5% vs. 22.5%; 72.0% vs. 28.0%, respectively). Metabolic pathways also showed significant dissimilarity between equol producers and non-producers (P = 0.001), and seven metabolic pathways were identified to be associated with the equol concentration in urine. Previously reported equol production-related gene sequences in A. equolifaciens 19450T showed higher relative abundance in equol producers than in non-producers. Additionally, we found that equol production was significantly associated with the prevalence of dyslipidemia, including a marginal increase in serum lipids (27.1% vs. 50.0%, P = 0.02). Furthermore, equol production was not determined by intake of soy isoflavones, which suggested that gut microbiota is critical in the equol production process.

Conclusion: Both content and functioning of the microbial gut community significantly differed between equol producers and non-producers. Further, equol producers showed lower prevalences of dyslipidemia, which suggests the important role that equol might play in lipid metabolism by gut microbiota.

Keywords: Blood lipid; Dyslipidemia; Equol phenotype; Gut microbiota; Soy isoflavone.