• Laura Murphy

Meet Your Oestrobolome!



By now most of us have heard of the gut microbiome which refers to the many different types of microbes; bacteria, fungi, viruses and other microscopic living things, which live in your large intestine. Our gut microbiome helps to digest food, protects against pathogens (bad bugs), provides essential nutrients and enzymes; and trains the immune system but it also plays a role in balancing hormones. Hormonal imbalances can heavily impact metabolism, mood, reproduction, stress regulation and weight management in men and women. The main hormone that tends to be imbalanced is oestrogen and this imbalance can contribute to a wide range of symptoms including:

  • Heavy, painful and/or irregular periods

  • Breast tenderness

  • Peri-menopausal hot flushes, night sweats

  • Monthly irritability and mood swings

  • Low libido

  • Acne

  • Headaches

  • Unexplained weight gain

  • Depression and anxiety

  • Fatigue, slow cognition, poor memory.



So what does the health of our gut have to do with our hormones? Enter the oestrobolome!


The oestrobolome is defined as the microbes of the gut that are capable of metabolizing oestrogens. The term ‘oestrogen’ is used to collectively describe the metabolites which play a major role in women’s reproductive function, and a minor one in men’s. Oestradiol is the most potent and the other important, but less powerful oestrogens, are oestrone and oestriol. In order to keep our hormones in balance excess oestrogen needs to be metabolised and excreted from the body. This happens via a number of complex phases within the body.


Let's get into the science!


Simply put oestrogens undergo phase 1 biotransformation in the liver via a family of detoxification enzymes called the cytochrome (CYP). Here they are transformed, via hydroxylation, into highly reactive metabolites that are ‘good’ (protective) or ‘bad’ (carcinogenic). These metabolites then move onto phase 2 which involves a range of complex processes including methylation, sulphation and glucuronidation where they are conjugated (united) with other compounds in order to be neutralised. This conjugation makes them water soluble so they can be excreted via the urine or faeces. Issues can arise if there are problems with any of these processes but the one we are most interested in is glucuronidation.

During glucuronidation glucuronic acid is conjugated with the oestrogen to facilitate its elimination from the body. However glucuronidated oestrogens can be deconjugated back into free oestrogens by the oestrobolome. Microbes in the oestrobolome produce beta-glucuronidase, an enzyme that is responsible for this deconjugation. Deconjugated oestrogen can then be reabsorbed into the bloodstream where it contributes to overall oestrogen load.

When the gut microbiome is healthy, the oestrobolome produces just the right amount of beta-glucuronidase to maintain balanced oestrogen levels. However, when gut dysbiosis, an overgrowth of unhealthy microbes, is present, beta-glucuronidase activity may be altered leading to excess oestrogen. Not only does excess oestrogen result in the afore mentioned symptoms but it can also promote the development of oestrogen-related conditions including pre-menstrual syndrome, endometriosis, fibroids; breast, ovarian, and uterine cancer in women and even prostate conditions such as enlarged prostrate, prostatitis and prostate cancer in men.






Supporting our gastrointestinal system and therefore our oestrobolome is one way we can support keeping our hormones in balance. Diet and lifestyle factors are commonly known to disrupt the gut microbiome but there are things we can do to offset their effects.



  • Stress: scientists have shown that being under stress reduces the number and diversity of the microbiota which could potentially lead to dysbiosis. Our busy 21stcentury lifestyles can mean it’s hard to avoid stress but you can build some anti-stress practices into daily life including meditation, yoga, spending time in nature, exercise, spending time with friends/family, going for a massage, or even cuddling your dog has been shown to reduce our stress hormones.


  • Antibiotics: sometimes antibiotics are unavoidable yet they can alter the gut microbiome by wiping out the beneficial bacteria. It is therefore important to pay extra attention to your diet and consider a probiotic supplement during and after treatment to help repopulate your gut.

  • A processed diet: processed foods are often high in sugar, salt, saturated or trans fats, additives and preservatives which do our gut no favours. These can suppress the beneficial bacteria and allow an overgrowth of unhealthy microbes. Focusing on cooking from scratch with fresh ingredients can make all the difference to our gut microbiome.



Diet strongly influences the composition of the oestrobolome. Several dietary factors may have a positive impact on the oestrobolome by helping to rebalance gut bacteria and increase diversity.

  • Fermented foods including sauerkraut, kimchi, kombucha and kefir

  • Prebiotic foods including garlic, onions, leeks, Jerusalem artichokes, chicory and bananas

  • Plant-based foods high in dietary fibre including peas, beans, legumes, nuts, seeds and a variety of fruit and vegetables

  • Cruciferous vegetables including broccoli, cauliflower, Brussels sprouts, kale and cabbage

  • Aim for variety – you should include a rainbow of fruit and vegetables every day and some even suggesting eating 40 different types of fruits, vegetables and herbs each week!


If you found this article informative we'd love to know. Leave us a comment below and tag us on our Instagram story @nourishforlife_ie. o .

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Lisa@nourishforlife.ie

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Swords Road

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