"Estrobolome" is not a word most women have heard, and it should probably be better known than it is. It describes something genuinely useful: a specific part of your gut bacteria that has a direct hand in how much oestrogen circulates in your body. Understanding it does not require a biology degree, and once it clicks, several perimenopause patterns start making a lot more sense together instead of looking like separate, unrelated problems.
What the Estrobolome Actually Is
Based on articles retrieved from PubMed, the term describes "the aggregate of enteric bacterial genes whose products are capable of metabolising estrogens," first described in detail in a widely cited 2017 review of the estrogen-gut microbiome axis (Baker et al., Maturitas, 2017, DOI: 10.1016/j.maturitas.2017.06.025). Here is the short version of how it works. Your liver processes oestrogen and tags it for removal from the body. Certain gut bacteria produce an enzyme called beta-glucuronidase, which can strip that tag back off, reactivating the oestrogen and sending it back into circulation instead of letting it leave the body. A 2023 review in Gut Microbes describes this enzyme as "a vital regulator in female estrogen metabolism," directly influencing how much oestrogen your body actually has access to at any given time (Hu et al., Gut Microbes, 2023, DOI: 10.1080/19490976.2023.2236749).
In other words, your gut microbiome is not a bystander in your hormone picture. It is an active participant, continuously deciding how much of the oestrogen your ovaries and liver have already processed gets a second circulation instead of being excreted.
The Loop, Step by Step
Liver marks oestrogen for excretion
Gut bacteria produce beta-glucuronidase
Oestrogen is reabsorbed, not excreted
Diversity keeps the loop running predictably
Why This Matters More After 40
Established The relationship between oestrogen and the gut microbiome runs in both directions, and both directions shift through perimenopause. Based on articles retrieved from PubMed, a review summarising the current evidence on the gut microbiome in menopause found that menopause is associated with lower gut microbiome diversity and a shift toward a composition more similar to the male gut microbiome (Peters et al., International Journal of Women's Health, 2022, DOI: 10.2147/IJWH.S340491). A large study of over 2,300 people in the Hispanic Community Health Study confirmed this pattern at scale: postmenopausal women showed lower gut microbial diversity and altered composition compared to premenopausal women, alongside decreased abundance of the microbial beta-glucuronidase pathway, and these changes were associated with less favourable cardiometabolic profiles (Peters et al., mSystems, 2022, DOI: 10.1128/msystems.00273-22).
An earlier cross-sectional study at the US National Institutes of Health had already pointed in the same direction: in postmenopausal women (and in men), total urinary oestrogen levels were strongly and directly associated with fecal microbiome richness and diversity, meaning a richer, more diverse gut microbiome tracked with higher circulating oestrogen (Flores et al., Journal of Translational Medicine, 2012, DOI: 10.1186/1479-5876-10-253). Interestingly, the same association did not hold in premenopausal women, whose ovarian hormone production simply dominates whatever the gut microbiome is contributing. Once ovarian oestrogen production declines through perimenopause and menopause, the gut's contribution to your overall oestrogen picture becomes proportionally larger, not smaller.
Worth knowing
This is part of why perimenopause is not simply "oestrogen goes down and stays down." The gut microbiome's role in recirculating oestrogen means your day-to-day levels can be influenced by digestion, diet and gut health, on top of the underlying hormonal decline. It helps explain why symptoms can fluctuate rather than decline in a straight line.
Where This Connects to Histamine and Gut Symptoms You Already Know
If you have read my earlier post on histamine intolerance in perimenopause, this will sound familiar. Gut health, hormone levels and histamine tolerance are not three separate systems that happen to act up around the same time in midlife. They share the same underlying driver. Falling and fluctuating oestrogen affects gut bacterial diversity, can influence gut barrier integrity, and interacts with the same enzyme systems involved in both oestrogen and histamine breakdown. This is also likely part of the picture behind mood and anxiety changes in perimenopause. Based on articles retrieved from PubMed, a 2026 review specifically examining the gut microbiota's role in perimenopausal anxiety found that the menopause transition is associated with reduced microbial diversity and depletion of short-chain fatty acid producing bacteria, changes linked to increased intestinal permeability, altered tryptophan metabolism and dysregulated stress hormone activity, all pathways connecting gut health directly to emotional regulation (Marano et al., Nutrients, 2026, DOI: 10.3390/nu18050743).
Three Systems, One Shared Driver
Falling, fluctuating oestrogen touches all three around the same time, which is why symptoms cluster instead of appearing one at a time.
None of this means every gut symptom, hormone symptom or mood symptom in perimenopause has the same single cause. It means they are more interconnected than they look from the outside, and addressing gut health is rarely a wasted effort even when the presenting complaint looks purely hormonal, or purely digestive.
What Might Help
Emerging The honest evidence picture here is promising but still developing. Based on articles retrieved from PubMed, a 2025 review on prebiotic and probiotic solutions for menopause noted that declining oestrogen appears to influence the microbiome, which may in turn contribute to menopause-related conditions including weight gain, bone health and cognitive health, and that certain probiotic strains have been shown to increase bacterial diversity and improve metabolic health in menopausal women, though the authors were clear that "evidence remains limited regarding the specific underlying mechanisms" (Liaquat et al., Post Reproductive Health, 2025, DOI: 10.1177/20533691251340491). A broader review of the gut microbiome in female health reached a similar conclusion: several probiotic interventions have shown benefit in specific conditions, including some early evidence for support of postmenopausal bone health, but the field is still characterising which strains help which outcomes (Siddiqui et al., Biology, 2022, DOI: 10.3390/biology11111683).
- Fibre and plant diversity have the most consistent evidence. A wide variety of plant fibres feeds a wider variety of gut bacteria, which is the single most reproducible lever for supporting microbial diversity generally.
- Fermented foods can help, with a genuine caveat. Foods like yoghurt, kefir and sauerkraut support gut diversity in the research, but many fermented foods are also high in histamine. If you already know histamine is a trigger for you, introduce these slowly and individually rather than all at once.
- Prebiotic and probiotic supplements are a reasonable individual trial, not a guaranteed fix. The evidence for specific strains and doses in perimenopause specifically is still early. Track how you respond rather than assuming a supplement is working without checking.
- This supports, it does not replace, medical care. Persistent gut symptoms such as pain, bleeding, unintentional weight loss or a significant change in bowel habit need a GP assessment, not a gut-health routine on its own.
When to See Your GP
- New or worsening abdominal pain, especially if severe or persistent
- Unexplained weight loss alongside gut symptoms
- Blood in your stool, or a significant change in bowel habit lasting more than a few weeks
- Gut symptoms significant enough to be limiting your daily life
Gut health support is a reasonable, evidence-informed layer to add. It is not a substitute for investigating symptoms that fall outside a normal, everyday pattern.
Where Coaching Fits
As a Registered Nurse, I do not diagnose gut conditions or prescribe probiotics. What I do is help women see how their gut, hormone and histamine symptoms connect, build realistic, food-first habits that support gut diversity without turning eating into another source of stress, and recognise when a symptom needs a GP referral rather than another dietary tweak.
If you are not sure how much of your picture is gut-related, hormonal, or both, the free two-minute symptom check is a structured place to start, or you can book a free discovery call to talk it through.
Gut, Hormones and Histamine Are More Connected Than They Look
Take the free symptom check, or book a no-pressure discovery call to talk through what is actually going on.
Frequently Asked Questions
What is the estrobolome?
The estrobolome is the collection of gut bacteria and their genes that help regulate how much oestrogen recirculates in your body, rather than being excreted. A key enzyme called beta-glucuronidase, produced by certain gut bacteria, reactivates oestrogen that your liver has already marked for removal, sending it back into circulation instead.
Does gut health really affect hormone levels?
Yes. Research has found that gut microbial diversity is strongly associated with circulating oestrogen levels in postmenopausal women, and that menopause itself is linked with reduced gut microbial diversity. It is a two-way relationship: oestrogen influences the gut microbiome, and the gut microbiome influences how much oestrogen stays in circulation.
Is this why gut issues and histamine problems often appear together in perimenopause?
They share an underlying driver rather than one directly causing the other. Falling and fluctuating oestrogen affects gut bacterial diversity, gut barrier function and histamine breakdown capacity around the same time, so it is common to notice digestive changes, histamine reactions and hormonal symptoms clustering together rather than appearing as separate, unrelated problems.
What can I actually do to support my gut microbiome in perimenopause?
Fibre-rich, plant-diverse eating and fermented foods have the most consistent evidence for supporting a diverse gut microbiome, though anyone with histamine intolerance should introduce fermented foods cautiously, as many are also high in histamine. Prebiotic and probiotic supplementation shows promise in early research but the evidence for specific strains and doses in menopause is still limited. None of this replaces medical care for persistent gut symptoms, which should always be checked by a GP.
References
- Baker JM, Al-Nakkash L, Herbst-Kralovetz MM. Estrogen-gut microbiome axis: Physiological and clinical implications. Maturitas. 2017. DOI: 10.1016/j.maturitas.2017.06.025
- Hu S, Ding Q, Zhang W, Kang M, Ma J, Zhao L. Gut microbial beta-glucuronidase: a vital regulator in female estrogen metabolism. Gut Microbes. 2023. DOI: 10.1080/19490976.2023.2236749
- Peters BA, Santoro N, Kaplan RC, Qi Q. Spotlight on the Gut Microbiome in Menopause: Current Insights. International Journal of Women's Health. 2022. DOI: 10.2147/IJWH.S340491
- Peters BA, Lin J, Qi Q, et al. Menopause Is Associated with an Altered Gut Microbiome and Estrobolome, with Implications for Adverse Cardiometabolic Risk in the Hispanic Community Health Study/Study of Latinos. mSystems. 2022. DOI: 10.1128/msystems.00273-22
- Flores R, Shi J, Fuhrman B, et al. Fecal microbial determinants of fecal and systemic estrogens and estrogen metabolites: a cross-sectional study. Journal of Translational Medicine. 2012. DOI: 10.1186/1479-5876-10-253
- Marano G, d'Abate C, Ianes I, et al. The Gut Microbiota in Perimenopausal Anxiety: A Novel Therapeutic Pathway Through Diet. Nutrients. 2026. DOI: 10.3390/nu18050743
- Liaquat M, Minihane AM, Vauzour D, Pontifex MG. The gut microbiota in menopause: Is there a role for prebiotic and probiotic solutions? Post Reproductive Health. 2025. DOI: 10.1177/20533691251340491
- Siddiqui R, Makhlouf Z, Alharbi AM, Alfahemi H, Khan NA. The Gut Microbiome and Female Health. Biology. 2022. DOI: 10.3390/biology11111683