Your Gut Bacteria and Your Hormones: Meet the Estrobolome

Your gut is home to trillions of tiny living things called bacteria. Together they are called the gut microbiome. Most people know they help with digestion, but they also play a part in how your body handles a hormone called estrogen. I'm sharing this new research from DiagosTechs.com

What is estrogen?

Estrogen is a hormone, which is a chemical messenger that travels through the blood and tells different parts of the body what to do. It is important for reproduction and for keeping many tissues healthy. The body needs just the right amount: not too little and not too much.

So what is the estrobolome?

The estrobolome is the group of gut bacteria that can affect how much estrogen is moving around in your body. It is a natural part of your larger gut microbiome.[1,2]

The package story

Think of estrogen like a package that your body is done using and wants to get rid of. Here is how it works when everything goes well:

1. The liver wraps the used estrogen up and seals it, which makes it inactive. Scientists call this "conjugated."

2. The sealed package is stored in bile, a digestive fluid kept in the gallbladder.

3. After you eat some fat, bile flows into the small intestine.

4. The package leaves the body in your poop.[6]

That is the ideal path. But some gut bacteria make an enzyme called beta glucuronidase. Think of it as a tiny pair of scissors. It can cut the package open and turn the estrogen back on. Once that happens, the estrogen can slip back into the blood and start working again.[1,6]

That trip back into the body is called enterohepatic recycling.[4,6] It can happen more often when the gut bacteria are out of balance (called dysbiosis) or when a person does not get enough fiber in their food.[4,6]

Why does reactivated estrogen matter to the body?

Active estrogen attaches to special docking spots on cells called estrogen receptors (ERα and ERβ). When it docks, it switches on certain jobs inside the cell and influences genes involved in estrogen signaling. This affects the reproductive organs and other tissues that respond to hormones.[1]

If the gut bacteria change how much estrogen is switched back on, the amount in the blood can go up or down. Researchers think this could be connected to health concerns linked to low or high estrogen, such as infertility, PCOS (also called PMOS), autoimmune conditions, endometriosis, and hormone sensitive cancers.[1,3,4,5] Scientists are still studying how strong these connections are.

Which bacteria have the scissors?

Many kinds of gut bacteria can make beta glucuronidase, including some types of Bifidobacterium, Lactobacillus, Clostridium, and E. coli.[4,7,8,9] But not every strain of every bacterium has the enzyme. In one study, only 2 out of 14 strains of Klebsiella had it.[9] And some bacteria are much stronger at it than others. One called C. perfringens made about 34 times more of the enzyme than several other types.[9]

Scientists have also found early signs of a second helper enzyme called steroid sulfatase (STS). It can turn another stored form of estrogen, called E1 sulfate, back into active estrogens. Some Klebsiella strains seem to make it, but much more research is needed.[10,11]

What does this mean for women's health?

A balanced estrobolome seems to be important for healthy reproduction. In one animal study, mice raised with no gut bacteria had trouble reproducing, and it returned to normal once the bacteria were added back.[7]

Gut imbalance in general has been linked to metabolic syndrome, PCOS, obesity, diabetes, inflammatory bowel disease, and cancer.[6,12,13,14,15] Researchers still need to find out whether the estrogen changes are part of the reason.

Where is the research going?

Scientists want to study both the gut and vaginal microbiomes to get a fuller picture.[6,16,17] In the future, this could lead to new ways to rebalance the microbiome, such as targeted probiotics and other approaches.[6,18] The hope is safer, more personalized care for people with PCOS, endometriosis, and other hormone related conditions.[5,15,19]

The big idea

Your gut bacteria are not just along for the ride. They help decide whether estrogen leaves the body or gets a second turn. Caring for your gut, including eating enough fiber, is one piece of supporting healthy hormones.

A Note From Dr. Linda

Too many women, especially in the county where I live, develop breast cancer. In addition to this referenced article, please check out my three part Breast Health Series, available to you through my website. You will discover simple steps to lower your risk and to help decrease the chance of recurrence.

It is normally $9.97, but as a thank you for being my reader, I am offering it to you for a special price of $4.97. Please message me if you would like to take advantage of this offer.

As always here' to your best health!

Dr Linda

References

1. Scarfò G, Daniele S, Chelucci E, et al. Endometrial Dysbiosis: A Possible Association with Estrobolome Alteration. Biomolecules. 2024;14(10):1325. doi:10.3390/biom14101325

2. Muccee F, Ghazanfar S, Ajmal W, Al-Zahrani M. In-Silico Characterization of Estrogen Reactivating β-Glucuronidase Enzyme in GIT Associated Microbiota of Normal Human and Breast Cancer Patients. Genes (Basel). 2022;13(9):1545. doi:10.3390/genes13091545

3. Cuffaro F, Russo E, Amedei A. Endometriosis, Pain, and Related Psychological Disorders: Unveiling the Interplay among the Microbiome, Inflammation, and Oxidative Stress as a Common Thread. Int J Mol Sci. 2024;25(12):6473. doi:10.3390/ijms25126473

4. Hu S, Ding Q, Zhang W, et al. Gut microbial beta-glucuronidase: a vital regulator in female estrogen metabolism. Gut Microbes. 2023;15(1):2236749. doi:10.1080/19490976.2023.2236749

5. Patel J, Chaudhary H, Rajput K, et al. Assessment of gut microbial β-glucuronidase and β-glucosidase activity in women with polycystic ovary syndrome. Sci Rep. 2023;13(1):11967. doi:10.1038/s41598-023-39168-5

6. Prakash A, Nourianpour M, Senok A, Atiomo W. Polycystic Ovary Syndrome and Endometrial Cancer: A Scoping Review of the Literature on Gut Microbiota. Cells. 2022;11(19):3038. doi:10.3390/cells11193038

7. Alghetaa H, Mohammed A, Singh NP, et al. Estrobolome dysregulation is associated with altered immunometabolism in a mouse model of endometriosis. Front Endocrinol (Lausanne). 2023;14:1261781. doi:10.3389/fendo.2023.1261781

8. Little MS, Pellock SJ, Walton WG, et al. Structural basis for the regulation of β-glucuronidase expression by human gut Enterobacteriaceae. Proc Natl Acad Sci U S A. 2018;115(2):E152-E161. doi:10.1073/pnas.1716241115

9. Leung JW, Liu YL, Leung PS, et al. Expression of bacterial beta-glucuronidase in human bile: an in vitro study. Gastrointest Endosc. 2001;54(3):346-350. doi:10.1067/mge.2001.117546

10. Benagiano G, Pluchino N, Archer DF, Stanczyk FZ. Estrobolome: Is there a missing link?. J Steroid Biochem Mol Biol. 2026;259:106967. doi:10.1016/j.jsbmb.2026.106967

11. Yoon HY, Kim HJ, Jang S, Hong JI. Detection of bacterial sulfatase activity through liquid- and solid-phase colony-based assays. AMB Express. 2017;7(1):150. doi:10.1186/s13568-017-0449-3

12. Min Q, Geng H, Gao Q, Xu M. The association between gut microbiome and PCOS: evidence from meta-analysis and two-sample mendelian randomization. Front Microbiol. 2023;14:1203902. doi:10.3389/fmicb.2023.1203902

13. Sun J, Wang M, Kan Z. Causal relationship between gut microbiota and polycystic ovary syndrome: a literature review and Mendelian randomization study. Front Endocrinol (Lausanne). 2024;15:1280983. doi:10.3389/fendo.2024.1280983

14. Wydra J, Szlendak-Sauer K, Zgliczyńska M, et al. Gut Microbiota and Oral Contraceptive Use in Women with Polycystic Ovary Syndrome: A Systematic Review. Nutrients. 2024;16(19):3382. doi:10.3390/nu16193382

15. Kukaev E, Kirillova E, Tokareva A, et al. Impact of Gut Microbiota and SCFAs in the Pathogenesis of PCOS and the Effect of Metformin Therapy. Int J Mol Sci. 2024;25(19):10636. doi:10.3390/ijms251910636

16. Aragón A, Jurado R, Jara J, et al. Investigating the Metabolism of Estrogens in Ligilactobacillus salivarius Strains Isolated from Human Milk and Vaginal Microbiota. Nutrients. 2024;16(6):861. doi:10.3390/nu16060861

17. Yu X, Li X, Yang H. Unraveling intestinal microbiota’s dominance in polycystic ovary syndrome pathogenesis over vaginal microbiota. Front Cell Infect Microbiol. 2024;14:1364097. doi:10.3389/fcimb.2024.1364097

18. Sekito T, Hirakawa H, Sadahira T. Unraveling the vaginal microbiota-based etiology of recurrent cystitis: the potential role of Lactobacillus vaginal suppositories. Ther Adv Urol. 2026;18:17562872261448600. doi:10.1177/17562872261448600

19. Sobstyl A, Chałupnik A, Mertowska P, Grywalska E. How Do Microorganisms Influence the Development of Endometriosis? Participation of Genital, Intestinal and Oral Microbiota in Metabolic Regulation and Immunopathogenesis of Endometriosis. Int J Mol Sci. 2023;24(13):10920. doi:10.3390/ijms241310920

This information is for educational purposes only and is not intended as a substitute for medical care. Always consult with your healthcare provider for advice before you begin taking new supplements. You are responsible for all of the health choices you make.