March is Endometriosis Awareness Month, and for me this topic sits at the intersection of worlds: my work as a researcher in physiology and microbiome science, and my personal experience living with endometriosis.
I was diagnosed at 21 years old.
At the time, I didn’t really understand what that meant. I had a laparoscopic surgery, lesions were removed, and I walked away assuming the problem had been “fixed.” I thought that painful periods would simply disappear.
They didn’t.
What followed was a familiar pathway for many women with endometriosis:
different oral contraceptive pills, hormonal suppression strategies, and a lovely Implanon experience that resulted in bleeding every day for six months (how the GP kept a straight face saying "it will settle down soon" I do not know).
At the time, none of it felt connected. It was just a series of interventions.
Years later, when trying to grow our family, I was advised to undergo another laparoscopic surgery.
When I woke from surgery, the message I heard was one that many women recognise:
“It was a mess in there.”
The endometriosis was stage III–IV.
What followed were multiple IVF cycles and pregnancy losses, and something that genuinely shocked me as both a patient and a scientist: When broaching a discussion around unsuccessful fertility treatment and the role of Endometriosis my specialist said "Endometriosis does not impact fertility."
As someone trained to interpret scientific literature, and someone who was teaching research interpretation and supervising PhD students, this statement was not (and is not) supported by the evidence.
But what struck me even more was the lack of two-way communication. Questions were dismissed rather than explored. I left wondering how someone without an understanding of health and physiology would possibly navigate these conversations.
So I did what researchers do.
I went back to the literature.
Endometriosis Is More Than a Reproductive Disease
Endometriosis affects an estimated 1 in 9 women of reproductive age in Australia and over 190 million women globally.
Yet despite its prevalence, it is still often framed narrowly as a gynaecological condition characterised by pelvic pain.
The science tells a different story.
Endometriosis is increasingly understood as a systemic inflammatory and immune-mediated disease involving:
- Chronic inflammation
- Altered immune surveillance
- Hormonal signalling disruption
- Metabolic changes
- Microbiome alterations
These systems do not operate in isolation.
They interact constantly.
Which is where the gut microbiome enters the conversation.
The Gut–Immune–Hormone Connection
Your gut microbiome is not just involved in digestion. It is a major regulator of the immune system, inflammatory pathways, and hormone metabolism - all systems playing a role in endometriosis.
In fact, around 70–80% of immune cells reside in the gut-associated lymphoid tissue, meaning microbial signals strongly influence immune behaviour.
Several mechanisms have emerged in the research:
1. Immune Dysregulation
Endometriosis involves altered immune surveillance. The dysregulation of immune system cells, such as macrophages, natural killer cells, and T cells contributes to the pathogenesis of endometriosis by enhancing the development and progression of endometriosis lesions.
Our microbiome influences this process through:
- Regulatory T cell signalling
- macrophage activation
- cytokine production
Short-chain fatty acids (SCFAs), particularly butyrate, produced by fibre-fermenting gut bacteria help regulate inflammatory signalling and immune tolerance.
Experimental studies suggest butyrate may suppress endometriotic lesion growth and inflammatory signalling pathways.
2. The Oestrobolome
A specific subset of gut bacteria, known as the oestrobolome, plays a role in regulating circulating oestrogen levels.
These microbes produce enzymes called β-glucuronidases, which influence whether oestrogen is eliminated or reabsorbed in the gut.
Alterations in the oestrobolome may contribute to elevated circulating oestrogen, a hormone environment often associated with endometriosis progression.
3. Inflammation and Microbial Balance
Several studies have identified altered microbial diversity and composition in individuals with endometriosis.
Research suggests shifts in:
- Firmicutes/Bacteroidetes balance
- Lactobacillus populations
- inflammatory microbial species
Animal models have even shown that transferring microbiota from endometriosis models can increase lesion growth, highlighting the role of microbial signalling in disease progression.
While human research is still evolving, the evidence increasingly suggests that microbial ecosystems influence the inflammatory environment in which endometriosis develops.
The gut microbiome community structure has also been shown to change across Endometriosis stage with Stage I-II microbiomes different from Stage III-IV, and differing significantly in women with severe Endometriosis and pain (dysmenorrhea).
The Moment the Pieces Started Connecting
While navigating IVF, surgeries, and pregnancy losses, I began to look at Endometriosis through a broader lens. Not just through the ovaries or uterus, but rather through systems.
At the time, my research and teaching focused heavily on inflammation, physiology, and immune signalling. In parallel, we were studying the gut microbiome and its systemic effects.
The connections began to emerge.
Inflammation.
Immune signalling.
Microbial metabolites.
Hormone metabolism.
Endometriosis is deeply intertwined with these systems.
And yet historically, the conversation around management rarely extended beyond surgery and hormonal suppression.
This realisation shaped the work I do today
Why the Microbiome Matters
Supporting the gut microbiome is not about “curing” endometriosis.
But it does influence several biological pathways relevant to the condition:
- immune regulation
- inflammatory signalling
- oestrogen metabolism
- metabolic health
- gut barrier integrity
Dietary fibre, polyphenols, and specific microbial metabolites play a role in shaping these pathways.
This is why conversations around microbiome-supportive nutrition and lifestyle are increasingly becoming part of the broader endometriosis research landscape.
From Research to Advocacy
For me, this journey changed the direction of my work.
What began as trying to understand my own experience evolved into a deeper commitment to educating and empowering women with evidence-based information.
Not fear-based messaging. Not miracle cures. Just better science – translated into practice.
Because endometriosis deserves more than outdated narratives and one-dimensional treatment approaches.
We deserve to be heard, to ask questions, and to understand the systems affecting our bodies.
Looking Forward
We are moving toward a systems-based understanding of women’s health - where reproductive health, metabolism, immunity, and the microbiome are recognised as deeply interconnected.
And that shift opens new opportunities for research, clinical care, and support.
If there’s one thing my journey has reinforced, it’s this:
When women are given knowledge, context, and a seat at the table, they become powerful advocates for their own health.
And that’s exactly what this month is about.
References
Ahmed RS, Sherif M, Alghamdi MA, El-Tallawy SN, Alzaydan OK, Pergolizzi JV, Varrassi G, Zaghra Z, Abdelsalam ZS, Kamal MT, Coluzzi F. Exploring the Immune System's Role in Endometriosis: Insights Into Pathogenesis, Pain, and Treatment. Cureus. 2025
Cai Z, Zhou Z, Huang S, Ma S, Chen Y, Cao Y, Ma Y. Gut microbiome in patients with early-stage and late-stage endometriosis. BMC Womens Health. 2025
Cuffaro F, Russo E, Amedei A. Endometriosis, Pain, and Related Psychological Disorders: Unveiling the Interplay among the Microbiome, Inflammation, and Oxidative Stress as a Common Thread. Int J Mol Sci. 2024 Jun 12;25(12):6473.
Griffiths MJ, Horne AW, Gibson DA, Roberts N, Saunders PTK. Endometriosis: recent advances that could accelerate diagnosis and improve care. Trends Mol Med. 2024 Sep;30(9):875-889.
Shigesi N, Harris HR, Fang H, Ndungu A, Lincoln MR; International Endometriosis Genome Consortium; 23andMe Research Team; Cotsapas C, Knight J, Missmer SA, Morris AP, Becker CM, Rahmioglu N, Zondervan KT. The phenotypic and genetic association between endometriosis and immunological diseases. Hum Reprod. 2025 Jun 1;40(6):1195-1209.
Watson C. The gut microbiome and chronic pain. Nature. 2024 Sep;633(8031):S34-S36.
