The Role of Dietary Fibre in Managing Endometriosis: Evidence and Practical Insights for Dietitians

Endometriosis is a chronic inflammatory condition characterized by the presence of ectopic endometrial tissue—tissue similar to the lining of the uterus (endometrium) that grows outside the uterus.

Unlike normal endometrial tissue, which thickens and sheds during the menstrual cycle, ectopic tissue remains trapped in areas like the ovaries, fallopian tubes, or pelvic cavity. This leads to inflammation, scarring, pain, and sometimes infertility.

Endometriosis can be an incredibly painful and complex condition. People living with endometriosis often describe the pain as “sharp knives stabbing”, “barbed wire” and “shooting pain”.

The management of endometriosis is often multifaceted and many include:

NSAIDs
Hormonal treatments like oral contraceptive pills or GnRH agonists
Gonadatropin
Lifestyle interventions including diet, physical activity and pain management strategies
Laparoscopic surgery
Hysterectomy

Diet, on its own or in combination with other treatments, can provide a unique opportunity to alleviate symptoms and support overall health in people living with endometriosis.

Among dietary factors, fibre has a in managing endometriosis due to its roles in:

Regulating hormones
Reducing inflammation
Improving digestive symptoms

This article explores the mechanisms by which fibre may influence endometriosis, reviews relevant research, and provides practical recommendations that you can use with your clients.

How Fibre Supports Endometriosis Management

There are three ways in which including fibre rich foods can help management endometriosis symptoms:

Regulating estrogen levels
Reducing systemic inflammation by supporting a healthy gut microbiome
Improving gastrointestinal symptoms that exacerbate endometriosis pain

Regulating Estrogen Levels

Endometriosis is an estrogen-dependent condition, meaning that elevated estrogen levels contribute to the growth and maintenance of endometriosis lesions. Estradiol, the most potent form of estrogen, is also synthesized locally within lesions, creating a self-perpetuating cycle of growth and inflammation.

Dietary fibre can play a crucial role in regulating estrogen levels by binding to excess estrogen in the intestines:

After estrogen circulates through the body and is metabolized by the liver, it is secreted into the intestines via bile
Fibre prevents the reabsorption of estrogen by binding to it, facilitating excretion through feces
High-fibre diets may reduce circulating estradiol concentrations in endometriosis by 10–25%

Reducing Systemic Inflammation

Chronic inflammation is a hallmark of endometriosis, exacerbating pain and promoting the growth of lesions. Fibre may influence inflammation through its effects on the gut microbiome:

Production of Short-Chain Fatty Acids (SCFAs)

Fibre fermentation by gut bacteria produces SCFAs, such as butyrate, propionate, and acetate. SCFAs have potent anti-inflammatory properties, reducing the production of pro-inflammatory cytokines like TNF-α and IL-6
Observational studies have shown that the gut microbiome in people with endometriosis is altered
In a study on mice, the researchers found that altered gut microbiota drives lesion growth. They also found that SCFAs like butyrate inhibit the growth of lesions and reduce inflammatory cell infiltration
This is an area of emerging research and more human studies are needed

Reducing Oxidative Stress

Fibre-rich foods, derived from plant-based sources, also serve as a powerful source of antioxidants. These antioxidants, naturally occurring in plants, play a vital role in reducing oxidative stress and inflammation—two key drivers of endometriosis symptoms and progression.

Observational studies have shown that hat higher fruit and vegetable intake, which are primary sources of dietary fibre, was associated with lower systemic inflammation and improved reproductive health outcomes

Improving Gastrointestinal Health

Gastrointestinal symptoms, such as bloating, constipation, and pain, are common in individuals with endometriosis. fibre offers relief by increasing stool bulk and improving gut motility, fibre can help manage constipation, bloating and abdominal discomfort, which are frequently reported by individuals with endometriosis.

However, before introducing fibre, it is important to assess clients for IBS and their tolerance to different types of fibres. For example, there is some evidence that people living with IBS may benefit from a lower FODMAP diet.

Interestingly, intake of cruciferous vegetables has been associated with endometriosis diagnosis. This is likely due to the impact these vegetables have on digestive symptoms, such as bloating, gas, and abdominal discomfort. These symptoms can exacerbate pelvic pain, which may prompt individuals to seek medical care for their worsening condition.

Practical Recommendations for Dietitians

Encourage Adequate fibre Intake:
- Recommend 25–30 g/day from diverse sources, including fruits, vegetables, legumes, and whole grains
Tailor Recommendations:
- Adjust fibre types and amounts based on the patient’s gastrointestinal health and symptom response
Monitor Cruciferous Vegetable, FODMAP Intake and symptoms:
- Include them in moderation and encourage cooking to reduce sulfur and FODMAP content. Clients with endometriosis may benefit from keeping a food and symptoms journal
Prioritize Anti-Inflammatory Foods:
- Pair fibre with omega-3-rich foods (e.g., walnuts, flaxseeds) and antioxidants (e.g., berries) to further reduce inflammation

Conclusion

Dietary fibre holds significant potential in managing endometriosis symptoms through its effects on estrogen metabolism, inflammation reduction, and gut health. However, individual tolerance and fibre type are critical factors.

By integrating evidence-based strategies and personalizing interventions, dietitians can empower patients to harness the benefits of fibre while minimizing symptom exacerbation.