top of page

Hormones and the Gut - What is the Connection?

Updated: Jun 9

Do you experience digestive and/or hormonal symptoms such as constipation, diarrhoea, abdominal pain, indigestion, depression, anxiety, mood swings, acne, fatigue, weight gain, hot flushes, insomnia, lethargy, or brain fog?

You might not be surprised to learn that the gut microbiome and our hormones are very closely linked, and if you have imbalances in one system, it’s possible you might have issues in both of these important functional areas of your health.

Hormones are messenger molecules of our endocrine system, which all affect each other, and when healthy, they work together like a finely balanced orchestra. Research is showing that the gut microbiome may be one of the most important players in this orchestra, aka the conductor at the centre, producing some hormones and signalling to the various glands in the body when other hormones should be created and released (1, 2).

The Gut Microbiome

Research shows that the gut microbiome can be linked to hormonal imbalances such as Endometriosis (3), Polycystic Ovarian Syndrome (PCOS) (4), Pre-Menstrual Syndrome (PMS)(5), Menopause (6), Diabetes (7), and Thyroid disease (8).

If you experience hormone imbalances there’s a high likelihood that your gut could be a good starting point for correcting these.

If your gut microbes are imbalanced, or your digestive system is not functioning as it should, you may not be effectively absorbing the nutrients which are so necessary for keeping your hormones balanced.

The gut microbiome is a community of trillions of bacteria, fungi, viruses, and protozoa, that plays a role in our metabolism, immunity, and behaviour. It was once overlooked but is now gaining appreciation for its’ importance in optimal health and longevity (9).

Digestive symptoms such as constipation, diarrhoea, bloating, indigestion, pain and cramps, or reflux may be present when there is a bacterial imbalance in the gut, otherwise known as ‘dysbiosis’.

If our gut bacteria are imbalanced, there’s a good chance that we aren’t absorbing our vitamins and minerals as well as we should. And we know that a good supply of these nutrients is so important for making our hormones, and for them to work properly.

What’s the point of spending a lot of money on a healthy organic diet if you aren’t properly absorbing the nutrients from the food you eat?

Gut hormones are released by enteroendocrine cells scattered throughout the gastrointestinal tract, and they play many important roles in maintaining health, as they are important signals involved in the gut-brain axis. Therefore, gut hormones are key players in gut-brain axis-related disorders, which can range from gastrointestinal disorders to mental health disorders (10).

Gastrin is a hormone that stimulates the release of hydrochloric acid in the stomach. Without adequate stomach acid it is difficult to break down proteins. This can cause bloating and other gastrointestinal discomfort, and result in inefficient absorption of nutrients.

Sex Hormones

Constipation can be a major cause of hormonal problems especially for women during the perimenopause/menopause years. Women need to be effectively eliminating used oestrogen, via the faeces. When this system gets blocked, excess oestrogen can build up.

It is important to be having regular (daily) bowel movements so that these used hormones are being removed from the body, or they may end up getting recirculated into our system, creating a build-up of oestrogen. An excess of oestrogen has the potential to lead to a condition known as ‘oestrogen dominance’.

Symptoms of oestrogen dominance include PMS, breast tenderness, mood swings, headaches, weight gain, fatigue, and reduced libido.

Efficient bile production is also necessary for its’ help in removing used hormones from the body.

High levels of oestrogen are associated with changes in the gut microbiome, and conversely, a lack of oestrogen during menopause can be a cause of weight gain due to altered metabolism, which is partly controlled by our gut bacteria (6).

Menopause is a time when sex hormones such as oestrogen and progesterone have declined. This can result in symptoms such as hot flushes, night sweats, mood swings, and weight gain. Imbalances in the gut microbiome can exacerbate these symptoms, which highlights the importance of having a healthy balanced gut during this important transitional time in a woman’s life.

📸 by Daria Shevtsova

Stress hormones

When we are stressed, our body is in survival mode also known as ‘fight or flight’, which is triggered by the sympathetic nervous system, when our adrenal glands produce the stress hormones cortisol and adrenalin. Excessive cortisol can suppress our digestive function. For optimal digestion, it is important that we are in a relaxed state, otherwise known as ‘rest and digest’, activated by the parasympathetic nervous system.

Ongoing and uncontrolled excessive stress may eventually lead to adrenal dysfunction or ‘burn-out’, altered gut-brain interactions, which may result in an array of gastrointestinal disorders including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and gastro-esophageal reflux disease (GERD) (11).

Thyroid hormones

Thyroid hormones are converted into their active form in the gut. Therefore, the gut needs to be working efficiently for this conversion to occur. We also need a healthy functioning gut to produce the nutrients that are necessary for thyroid hormone production (8).

If the gut lining is damaged (intestinal permeability or ‘leaky gut’), undigested food molecules, proteins, bacteria, and toxins can leak through into our blood stream, causing an inflammatory and immune response, which has the potential to eventually lead to autoimmune diseases such as Hashimoto’s Thyroiditis or Graves Disease.


Hormone imbalances such as insulin resistance and diabetes, are closely correlated with imbalances in the gut. Insulin and glucagon are the hormones responsible for our blood sugar management, and when they become ‘dysregulated’ or imbalanced, symptoms such as sugar and carbohydrate cravings, irritability, low energy, and eventual weight gain or obesity can develop, due to inflammation and insulin resistance (7).

Imbalanced blood sugar can trigger high cortisol, which is implicated in inflammation and weight gain.

Furthermore, high saturated fat diets are now known to negatively impact the gut microbiome, which can lead to a state of dysbiosis, deregulate metabolism, and increase insulin resistance and inflammation, two key factors involved in the development of Type 2 diabetes mellitus (7).

Hunger hormones

Ghrelin is another hormone produced in the gut, which is also known as our ‘hunger hormone’ because it stimulates hunger and increases as the stomach empties.

Hormones such as leptin and ghrelin are secreted in the gut to control our appetite by sending signals to the brain to let it know when we are hungry or full. Ghrelin increases our appetite and hunger, while leptin signals to the brain that we are full, promoting meal-time cessation (12).

In summary, all of our hormones are interconnected, and our gut health is intrinsically connected to our hormone production, therefore, keeping the gut healthy is vitally important for keeping our hormones balanced and healthy.

How can we support our hormones through our diet and gut health?

  • Remove inflammatory triggers in the diet such as processed foods, refined vegetable oils, gluten, dairy, excessive sugar, alcohol, and caffeine.

  • Consume anti-inflammatory healthy fats such as oily fish, nuts, seeds, avocado, and extra virgin olive oil.

  • Increase plant-based fibre by eating a diversity of vegetables, fruit, nuts, seeds, whole grains, and legumes.

  • Include phytoestrogens such as flaxseeds, tofu, tempeh, chickpeas, and lentils to help balance oestrogen levels.

  • Consume fermented foods and drinks such as sauerkraut, kimchi, kefir, kombucha, yoghurt, tempeh, and miso for probiotic benefits (N.B. avoid if you have histamine issues).

  • Include polyphenol-rich foods such as berries, dark chocolate, extra virgin olive oil, green tea, and most fruits and vegetables.

  • Avoid refined carbohydrates and sugar as they cause blood sugar spikes and dips. Instead, eat meals consisting of healthy fats, protein, and complex carbohydrates, to maintain glycemic balance and a healthy insulin response.

  • Consume Bone broth or Collagen to support a healthy gut lining (again, avoid if you have histamine issues).

📸 by Taryn Elliot

Need personalised help?

If you are struggling with your hormones or gut health, you may need personalised support to determine the cause and help you to regain balance. Functional laboratory testing and a thorough case history helps us to find the root cause of your issues.

Please get in touch if you’d like to learn more or book in a FREE 15-minute call to discover how to find relief from your symptoms.

The GI EcologiX is a stool test that looks at the health of the microbiome using DNA technology. It looks for pathogenic bacteria, fungal overgrowth, as well as parasites and commensal (beneficial) bacteria. It also assesses gastrointestinal health markers for Helicobacter pylori, inflammation, digestive enzyme function, and the integrity of the intestinal lining. Read more here.

The DUTCH Complete Hormones test measures sex and adrenal hormones along with their metabolites. Additionally, the daily (diurnal) pattern of free cortisol is included along with melatonin, and organic acid markers for B vitamins and neurotransmitters. Read more here.

Order your copy of The Simple Gut Reset Cookbook for gut-supporting recipes.


1. Clarke G, Stilling RM, Kennedy PJ, Stanton C, Cryan JF, Dinan TG. Minireview: Gut microbiota: the neglected endocrine organ. Mol Endocrinol. 2014;28(8):1221-1238. doi:10.1210/me.2014-1108

2. El Aidy S, Dinan TG, Cryan JF. Gut Microbiota: The Conductor in the Orchestra of Immune-Neuroendocrine Communication. Clin Ther. 2015 May 1;37(5):954-67. doi: 10.1016/j.clinthera.2015.03.002. Epub 2015 Apr 3. PMID: 25846319.

3. Svensson, A., Brunkwall, L., Roth, B. et al. Associations Between Endometriosis and Gut Microbiota. Reprod. Sci. 28, 2367–2377 (2021).

4. Lindheim L, Bashir M, Münzker J, Trummer C, Zachhuber V, Leber B, et al. (2017) Alterations in Gut Microbiome Composition and Barrier Function Are Associated with Reproductive and Metabolic Defects in Women with Polycystic Ovary Syndrome (PCOS): A Pilot Study. PLoS ONE 12(1): e0168390.

5. Ayadilord, M., Mahmoudzadeh, S., Hoseini, Z.S. et al. Neuropsychological function is related to irritable bowel syndrome in women with premenstrual syndrome and dysmenorrhea. Arch Gynecol Obstet 302, 915–923 (2020).

6. Schreurs, M.P.H.; de Vos van Steenwijk, P.J.; Romano, A.; Dieleman, S.; Werner, H.M.J. How the Gut Microbiome Links to Menopause and Obesity, with Possible Implications for Endometrial Cancer Development. J. Clin. Med. 2021, 10, 2916.

7. Sikalidis, A.K.; Maykish, A. The Gut Microbiome and Type 2 Diabetes Mellitus: Discussing A Complex Relationship. Biomedicines 2020, 8, 8.

8. Knezevic J, Starchl C, Tmava Berisha A, Amrein K. Thyroid-Gut-Axis: How Does the Microbiota Influence Thyroid Function?. Nutrients. 2020;12(6):1769. Published 2020 Jun 12. doi:10.3390/nu12061769

9. Cresci GA, Bawden E. Gut Microbiome: What We Do and Don't Know. Nutr Clin Pract. 2015;30(6):734-746. doi:10.1177/0884533615609899

10. Sun LJ, Li JN, Nie YZ. Gut hormones in microbiota-gut-brain cross-talk. Chin Med J (Engl). 2020;133(7):826-833. doi:10.1097/CM9.0000000000000706

11. Konturek PC, Brzozowski T, Konturek SJ. Stress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options. J Physiol Pharmacol. 2011 Dec;62(6):591-9. PMID: 22314561.

12. Zanchi D, Depoorter A, Egloff L, Haller S, Mählmann L, Lang UE, Drewe J, Beglinger C, Schmidt A, Borgwardt S. The impact of gut hormones on the neural circuit of appetite and satiety: A systematic review. Neurosci Biobehav Rev. 2017 Sep;80:457-475. doi: 10.1016/j.neubiorev.2017.06.013. Epub 2017 Jun 29. PMID: 28669754.

119 views0 comments


bottom of page