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Published on: November 15, 2013
Gut Bacteria Encode Reductases that Biotransform Steroid Hormones.
Gabriela Arp1, Angela Jiang1,2, Keith Dufault-Thompson2
1Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, College Park, Maryland, USA.
Gut bacteria enzymes modify steroid hormones, impacting host health. These enzymes, prevalent in females, offer insights into microbial steroid metabolism and women's hormonal health.
Area of Science:
- Microbiology
- Endocrinology
- Biochemistry
Background:
- Gut microbiome plays a crucial role in steroid metabolism.
- Microbial steroid metabolism influences host hormone homeostasis, affecting development, mental health, and reproduction.
Purpose of the Study:
- To identify and characterize key enzyme families involved in microbial steroid metabolism in the human gut.
- To understand the evolutionary specialization and functional roles of these enzymes.
- To investigate the prevalence of these enzymes in human populations and their potential sex-specific enrichment.
Main Methods:
- Phylogenetic reconstruction
- Site-directed mutagenesis
- Metagenomic analysis
Main Results:
- Identified Δ4-3-ketosteroid 5β-reductase, 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase, and Δ6-3-ketosteroid reductase enzyme families in gut bacteria.
- Demonstrated specialized functions of 5β-reductase and Δ6-3-ketosteroid reductase in steroid hormone conversion.
- Discovered a fused 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase-5β-reductase enzyme streamlining pregnenolone metabolism.
- Found these enzymes are common in healthy individuals, with higher prevalence in females.
Conclusions:
- Provided molecular insights into microbial steroid metabolism pathways in the gut.
- Highlighted the enzymes' roles in steroid hormone modification and their prevalence.
- Suggested potential implications for hormonal health, particularly in women's health.
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