The link between our gut and our hormones

“I am seeing you to help me with my period, why are you asking about my gut???”

In my clinical practice I specialise in AFAB’s (assigned female at birth) reproductive health (e.g. menstrual cycle health) BUT at the root of so many of these presentations, we often find the gut being an upstream contributing driver of what is going on. So, while I wouldn't have called myself a gut specialist when I started out, I continue to upskill in evidence-based gut health support because whether someone is dealing with PMS, PMDD, PCOS, endometriosis, hypothalamic amenorrhea, or perimenopause symptoms, we need to consider the gut as a possible contributing factor.

Naturopathic medicine has long placed the gut at the centre of whole-body health. More current research is now clarifying how this works, not just that it matters, but the specific biological mechanisms involved - which is so cool. The microbiome and gut barrier is very important in immune signalling, inflammation, neurotransmitter production, nutrient metabolism, and hormone metabolism/regulation. Our gut health is therefore, deeply interconnected with nearly every system in our body.

Let’s look at a few big reasons how your gut health connects with your hormones….

The estrobolome

Within your gut microbiome lives a functionally distinct subset of bacteria more recently referred to as the estrobolome.   These bacteria produce enzymes called β-glucuronidase and β-glucuronidase is responsible for deconjugating oestrogen in the gut (essentially stripping off a molecule that tagged with in the liver and signalling  it for excretion via the colon) allowing it to be reabsorbed into circulation. 

Now β-glucuronidase activity is not uniformly "good" or "bad",  its up- and down-regulation appears to be partly life-stage dependent, and both excess and deficiency have clinical relevance depending on the individual's hormonal context. When the estrobolome is healthy and diverse, this recycling is well-regulated. 

When it is disrupted, however, through dysbiosis (when opportunistic bacteria that produce it overcrowd the beneficial bacteria), excess reabsorption may contribute to oestrogen dominance symptoms, while an underactive estrobolome may contribute to lower circulating oestrogen. 

In other words, the health of your microbiome impacts how oestrogen is regulated in your body and we actually have tools that can improve this directly when things get out of whack. 

LPS, inflammation, and reproductive health

In addition to β-glucuronidase activity, other aspects of gut health can impact our hormones and cycle. Opportunistic bacteria can also produce lipopolysaccharide (LPS): an inflammatory molecule. LPS causes inflammation in the gut and can also translocate into circulation if the barrier of the gut is compromised, triggering low-grade systemic inflammation and elevating further inflammation and immune activation. 

Elevated LPS has been associated with both endometriosis, PCOS, PMS, PMDD, and may contribute to severe perimenopause symptoms in some cases. Addressing these bacteria can help lower LPS and therefore inflammation and immune activation. 

Histamine

Some gut bacteria are histamine-producers, and when these are overrepresented, histamine load can become excessive. Oestrogen upregulates histamine receptors, meaning the oestrogen-histamine relationship is bidirectional: high histamine can worsen oestrogen-related symptoms, and high oestrogen can increase histamine sensitivity. This is particularly relevant for women with premenstrual or perimenopausal mood symptoms, anxiety, as well as allergy hypersensitivity & reactivity. 

Absorption issues

Finally, we need nutrients to support the production, metabolism, and function of hormones as well as reproductive health in general. Things impacting absorption such a lack of the good bacteria that help convert certain nutrients into their active forms, digestive enzymes, and inflammation may impact our nutrient status, which can then impact our hormone/reproductive health. 

What about perimenopause? 

Whilst we are still needing stronger evidence and better controlled trials, some research suggests that gut health may impact symptom severity during the perimenopause/menopause transition. For example, some studies suggest that post-menopausal women with menopausal syndrome (symptomatic menopause) have higher rates of gut health issues compared to asymptomatic menopausal women, which  suggests the microbiome may modulate symptom burden. It is interesting research that we need more of!

Soy isoflavones are evidence based nutrients we can use to support all reproductive health issues including perimenopause symptoms as well as protect long term health with AFABS. For more information on this read our previous blog on soy isoflavones. Improved gut health may help with better absorption and, therefore utilisation of these nutrients.

In general, it is suggested that aging alone impacts the health of our microbiome with a likely decrease in microbiome diversity and more wear and tear on barrier function through an increase in oxidative stress.

Whether it is the perimenopause transition or just aging - the main point is, we can definitely support our gut health to support our overall health throughout our lifetime as a protective factor for overall health.

What this all means and what you can do: practical starting points

Supporting your gut health is a protective factor not just for reproductive health but health overall.

Some of the basic evidence based things to consider:

Prioritise wholefoods: A wholefoods diet rich in lean protein, omega 3 fatty acids, veggies, whole grain, legumes, etc provide nutrient density as well as keep inflammation and oxidative stress down. This in general supports gut health. 

Eat for diversity: Aiming for 30+ different plant foods per week (vegetables, fruits, legumes, nuts, seeds, wholegrains) has been shown to be a strong predictor of microbiome diversity (McDonald et al., 2018).

Make sure you are getting enough fibre: Fibre in general is really great for gut health and research shows most of us are not getting enough. Adult men need a minimum of 30 g and women 25 g. Fibre keeps motility patterns healthy (which helps the excretion part of conjugated estrogen, which supports gut health.  Fibre also feeds beneficial bacteria in the gut acting as a prebiotic. 

Include fermented foods if tolerated: A more recent randomised control trial showed that a high-fermented-food diet significantly increased microbiome diversity and reduced inflammatory markers (Wastyk et al., 2021). If an individual has histamine issues, they may not tolerate fermented foods well. Addressing the root cause of this so that you can tolerate these foods and get the benefit from them is possible - find some support if needed. 

Prioritise sleep & manage stress: The gut-brain axis is bidirectional and mechanistically well-established. Sleep deprivation and chronic stress alters gut motility, barrier function, and microbial composition. 

Move your body and recover: Exercise is also shown to have a relationship with our gut health. Varghese et al. (2024) in a literature review discuss how combining aerobic and resistance training significantly affects bacterial diversity, linked to a lower prevalence of chronic metabolic disorders. Furthermore, exercise enhances gut microbiome diversity, increases SCFA production, improves nutrient utilization, and modulates neural and hormonal pathways, improving gut barrier integrity. Recovery is important as some literature also suggests that high-intensity exercise for a long duration can cause a leaky gut and consequent systemic inflammation, which may disrupt the microbial balance.

Protect your microbiome and gut barrier: Minimise unnecessary long term antibiotic use, NSAID use, excessive alcohol, smoking, processed food that can disrupt microbial balance and barrier integrity. If you do need to use these medications long term, speak with your practitioner about how you can protect your gut health in the process. 

Consider working with a qualified practitioner and testing if symptoms persist. If you've been doing "all the right things" and still struggling, further testing and targetted support may be a good idea. Seeing your GP can be a great start as they can do some routine tests. Working with a naturopath for more targeted gut support is helpful as well. 

If you would like more support in this area....

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