Women's health is a complex topic that is influenced by various factors. One emerging area of interest that has gained significant attention is the connection between oestrogen and the gut microbiome. Understanding this connection can empower women to make informed decisions about their health and well-being. So, let’s dive into the fascinating realm of the oestrogen-gut microbiome axis, exploring its physiological and clinical implications for women.

Oestrogen is an essential hormone in women and is crucial for reproduction but also involved in over 400 other physiological processes! Oestrogen is an ovarian steroid hormone that is responsible for the feminising characteristics of women and develops secondary sexual characteristic development such as breasts, development of female pelvic traits and fat distribution as well as:

Reproductive health
Bone density
Cardiovascular function
Regulates the menstrual cycle
Mood regulation
Maintain skin moisture and elasticity
Regulates body temperature
Increases metabolic rate
Improves sleep
Increases blood flow
Dilates small arteries
Enhances magnesium uptake
Decreases blood pressure
Improves mood
Enhances energy
Maintains bone density
Maintains the blood brain barrier
Improves oxygen transport and glucose to neurons

Recent studies have revealed a fascinating relationship between oestrogen and the gut microbiota – the diverse community of microorganisms in our digestive system. Oestrogen metabolism occurs not only in the reproductive organs but also in the gut, where certain bacteria have the ability to process oestrogen, the collection of these bacteria are called the Estrobolome. Conversely, oestrogen can influence the composition and function of the gut microbiome. This bidirectional interaction forms the basis of the oestrogen-gut microbiome axis!

Regulation of Oestrogen Levels

The gut microbiome helps regulate oestrogen levels by participating in oestrogen metabolism, which involves the breakdown, conversion, and elimination of oestrogen compounds. The gut bacteria produce enzymes that can modify oestrogen molecules, converting them into different forms. This metabolic activity can either increase or decrease the overall levels of oestrogen in the body. Imbalances in the gut microbiota composition, known as dysbiosis, can affect oestrogen metabolism and disrupt the delicate balance of oestrogen levels in the body. Dysbiosis may lead to elevated or low oestrogen levels and these imbalances may impact women’s health.

Disrupted oestrogen levels resulting from dysbiosis may contribute to conditions such as:

Endometriosis
Certain types of breast cancer
Polycystic ovary syndrome (PCOS)
Menstrual irregularities
Mood swings
Weight gain
Infertility
Bone density
Cardiovascular health in women
Hot flushes
Vaginal dryness
Decreased libido
An increased risk of osteoporosis and heart disease

Nutrient Absorption and Metabolism

The gut microbiome plays a crucial role in the absorption and metabolism of various nutrients, including phytoestrogens. Phytoestrogens are naturally occurring compounds found in certain plant-based foods, such as soybeans, flaxseeds, lentils, and some fruits and vegetables, that possess a chemical structure similar to human oestrogen. Due to this structural similarity, phytoestrogens can interact with oestrogen receptors in the body and exhibit weak oestrogenic activity. The conversion of phytoestrogens by the gut microbiome can result in different outcomes. Some phytoestrogens are converted into forms with higher oestrogenic activity, while others are transformed into compounds with reduced or even anti-oestrogenic properties.

Immune Function

A healthy gut microbiome plays a crucial role in maintaining a robust immune system. The gut is home to a large population of immune cells and houses an intricate network of interactions between the immune system and the gut microbiota. These interactions are essential for the proper development and functioning of the immune system.

One way in which the gut microbiome influences immune responses is through its interaction with oestrogen. As mentioned earlier, the gut bacteria can metabolise oestrogen compounds, affecting their levels and activity in the body, in turn, influencing immune responses. Oestrogen has been found to have immunomodulatory effects. Oestrogen can influence the production and activity of immune cells, such as T cells, B cells, and natural killer cells, as well as the secretion of cytokines and other immune signalling molecules.

Improving your gut health is essential for hormonal balance and can have far reaching benefits! The gut microbiota's role in oestrogen regulation highlights the need to prioritise gut health in hormone-related conditions.

Here are my top nutritional tips for improving microbial diversity:

Increase fibre intake, ideally between 35-45g/day for women
Consuming foods rich in polyphenols, such as colourful fruits and vegetables

Herbs, spices and teas: Turmeric, ginger, basil, oregano, thyme, etc., plus green tea and organic coffee in moderation
Avoid fad diets
Probiotic foods like yoghurt, kefir, sauerkraut, kimchi (if tolerated)
Variety! Try and consume 30-40 different plants each week (remember, plants are also nuts and seeds)

Foods to avoid:

Refined vegetable oils
Trans fats
Refined carbohydrates and processed grains
Added sugars & artificial sweeteners
Packaged and processed foods

The field of research on the oestrogen-gut microbiome axis highlights the intricate relationship between oestrogen and our gut microbiota. This connection has significant implications for women's health across the lifespan, influencing hormone balance, immune function, and the development of reproductive disorders. Recognising the importance of the relationship between the gut microbiota and hormones opens doors for new approaches to managing oestrogen-driven conditions. Women can support their hormonal health and overall well-being by prioritising a healthy gut through dietary changes and lifestyle modifications. Remember, optimal hormone balance begins in the gut.

UNTIL NEXT TIME, BE WELL

YOURS IN GREAT HEALTH,

References

Baker, J. M., Al-Nakkash, L., & Herbst-Kralovetz, M. M. (2017). Estrogen–gut microbiome axis: Physiological and clinical implications. Maturitas, 103, 45–53. https://doi.org/10.1016/j.maturitas.2017.06.025
Lyte, M., Villageliú, D. N., Crooker, B. A., & Brown, D. R. (2018). Symposium review: Microbial endocrinology—Why the integration of microbes, epithelial cells, and neurochemical signals in the digestive tract matters to ruminant health. Journal of Dairy Science, 101(6), 5619–5628. https://doi.org/10.3168/jds.2017-13589

The Oestrogen-Gut Microbiome Axis: Exploring Its Significance for Women's Health