How an Unhealthy Gut Affects Fertility and Hormone Balance

Katrine Nørgaard
Video
13 min

In this video, we explain how an unhealthy gut affects fertility and hormone balance. It covers common unhealthy gut symptoms, signs of poor digestion and how gut health influences hormones, inflammation and reproductive health in women and men.
Gut health plays a fundamental role in overall health, yet many people do not realise how deeply the digestive system influences fertility and hormone balance. The gut is responsible for far more than digestion alone. It affects nutrient absorption, immune function, hormone regulation and inflammation, all of which are essential for reproductive health in both women and men. When the gut is unhealthy, these systems can become disrupted, leading to symptoms that may seem unrelated but are closely connected.
Many digestive symptoms are common today, which often leads people to assume they are normal. Bloating after meals, constipation, irregular bowel movements or ongoing fatigue are frequently dismissed because so many others experience the same issues. However, common does not mean normal. These symptoms can be important signs of an unhealthy gut and may indicate imbalances that affect hormone balance and fertility over time.
Quick answer: An unhealthy gut can affect fertility by disrupting hormone regulation, increasing inflammation and reducing nutrient absorption. Common signs of an unhealthy gut include bloating, constipation, diarrhoea, irregular stool, fatigue and hormonal symptoms. Supporting gut health helps improve fertility by restoring balance in digestion, hormones and inflammation.
Why Gut Health Is Essential for Fertility
The digestive system is one of the most complex systems in the body and is connected to nearly every other system. Its primary roles include breaking down food, absorbing nutrients and eliminating waste products. Beyond these basic functions, the gut also communicates with the immune system, the nervous system and the hormonal system.
When gut health is optimal, the body can absorb and utilise nutrients efficiently, regulate hormones effectively and keep inflammation under control. All of these processes are essential for fertility. When digestion is impaired, the effects are rarely limited to the gut alone. Instead, imbalances can ripple throughout the body and affect reproductive health.
The Digestive System and Its Role in Hormone Balance
One of the lesser-known functions of the digestive system is its role in hormone regulation. The gut and gut microbiota help regulate hormones by supporting their production, activation and elimination. This is particularly important for reproductive hormones.
For women, the gut plays a key role in estrogen metabolism. Estrogen levels naturally rise and fall throughout the menstrual cycle. After estrogen has served its purpose, it needs to be broken down and eliminated from the body. The gut and gut microbiota are involved in this process. When digestion is slow or imbalanced, excess estrogen may not be cleared effectively, which can contribute to hormone imbalance.
For men, gut health also influences hormone balance and sperm quality. Inflammation, oxidative stress and poor nutrient absorption can all affect reproductive function.
Gut Health and Nutrient Absorption
Efficient digestion is essential for absorbing nutrients that support fertility. Nutrients involved in reproductive health must be absorbed and utilised properly in order to support hormone production, egg and sperm quality and implantation.
When the gut is unhealthy, nutrient absorption can be impaired. Even if a person eats a nutrient-rich diet or takes supplements, the body may struggle to absorb and use these nutrients effectively. Over time, this can contribute to fatigue, hormone imbalance and reduced fertility.
Inflammation, Gut Health and Fertility
The gut plays a central role in regulating inflammation in the body. A healthy gut barrier helps prevent unwanted substances from entering the bloodstream, while an unhealthy gut can allow irritants to pass through and trigger immune responses.
Chronic low-grade inflammation is particularly relevant for fertility. Inflammation can affect hormone balance, egg quality, sperm quality and implantation. In women, inflammation may interfere with the implantation of a fertilised egg. In men, inflammation can negatively affect sperm quality.
Maintaining a healthy gut helps keep inflammation at appropriate levels, supporting reproductive health.
What Is a Healthy Gut?
Before understanding how an unhealthy gut affects fertility, it is important to define what healthy digestion looks like. Many people are unsure whether their digestion is functioning well, especially if they have experienced the same symptoms for years.
A healthy gut is characterised by:
- Regular bowel movements
- Comfortable digestion without persistent pain or bloating
- Efficient nutrient absorption
- Balanced gut microbiota
- Effective elimination of waste products
Healthy digestion supports stable energy levels, balanced hormones and overall wellbeing.
Why Many People Misjudge Gut Health
Many people assume that digestive discomfort is normal because it is common. Bloating, gas or irregular bowel movements are often dismissed as part of everyday life. However, widespread symptoms do not mean they are healthy.
For example, while some gas after meals can be normal, significant bloating that causes the abdomen to appear swollen by evening is not a sign of optimal digestion. Persistent symptoms often indicate an underlying imbalance in gut health.
Signs of an Unhealthy Gut
An unhealthy gut can show up in many different ways. Some symptoms are directly related to digestion, while others affect other areas of the body.
Common unhealthy gut symptoms include:
- Bloating and excessive gas
- Constipation
- Diarrhoea
- Alternating stool consistency
- Abdominal pain or discomfort
- Reflux or nausea
When these symptoms occur regularly, rather than occasionally, they may indicate poor gut health.
Signs of an Unhealthy Gut Beyond Digestion
Because the gut is connected to many systems in the body, signs of an unhealthy gut may appear outside the digestive tract. These can include:
- Fatigue or low energy, especially after eating
- Skin issues such as acne, eczema or psoriasis
- Food sensitivities
- Hormonal imbalances
- PMS symptoms
- Headaches or migraines
- Joint pain
- Mood changes, anxiety or low mood
While these symptoms can have multiple causes, they are often seen alongside digestive issues when gut health is compromised.
Stool Health as a Window Into Gut Health
Stool can provide valuable insight into digestive health. Observing stool consistency, frequency and appearance can help identify signs of imbalance.
Stool consistency
The Bristol stool scale categorises stool into seven types. A healthy stool is usually type 4, which is smooth, soft and easy to pass. Persistent constipation, loose stools or frequently changing stool types may indicate digestive imbalance.
Frequency
Ideally, bowel movements occur once or twice daily, depending on food intake. Regular elimination helps remove waste products and excess hormones from the body.
Stool Colour and What It Can Indicate
Healthy stool is typically brown, though colour can vary based on diet. Certain colours may provide additional information:
- Green or yellow stool may indicate rapid digestion
- Pale or grey stool may be linked to bile or liver issues
- Black stool or visible blood should always be investigated by a healthcare professional
Mucus in the stool can indicate irritation or inflammation in the gut lining, while undigested food may suggest poor digestion.
How an Unhealthy Gut Affects Hormones
When digestion is impaired, hormone regulation can suffer. An unhealthy gut may:
- Reduce the body’s ability to eliminate excess hormones
- Increase inflammation that disrupts hormone signalling
- Contribute to hormonal imbalances such as estrogen dominance
In women, this may affect menstrual cycles and ovulation. In men, hormone imbalance can influence sperm quality.
Gut Microbiome and Fertility
The gut microbiome refers to the collection of microorganisms living in the digestive tract. A balanced microbiome supports digestion, hormone regulation and immune function.
When the microbiome is imbalanced, a condition known as dysbiosis, it can:
- Increase inflammation
- Affect hormone metabolism
- Contribute to oxidative stress
Oxidative stress can damage eggs and sperm and negatively affect fertility in both women and men.
Unhealthy Gut and Oxidative Stress
Oxidative stress occurs when the body has more free radicals than it can neutralise. Certain unhealthy gut microbes are associated with higher levels of oxidative stress.
Elevated oxidative stress can affect:
- Egg quality
- Sperm quality
- Hormonal signalling
Supporting gut health helps reduce oxidative stress and protect reproductive cells.
Gut Health, Stress and Fertility
Digestive symptoms themselves can be a source of stress and anxiety. Chronic stress can, in turn, worsen digestion and disrupt hormone balance.
This creates a cycle where poor gut health increases stress, and stress further impairs digestion. Over time, this cycle can negatively affect fertility. Supporting gut health can help reduce stress-related effects on the body.
Metabolic Health and an Unhealthy Gut
An unhealthy gut may increase the risk of metabolic imbalances such as insulin resistance. Metabolic health is closely linked to hormone regulation and fertility.
Imbalances in gut health can influence blood sugar regulation, which in turn can affect sex hormones in both women and men.
Tracking Digestion to Improve Awareness
Many people are unaware of patterns in their digestion. Tracking daily habits can help identify triggers and connections between food, symptoms and energy levels.
A digestion tracker may include:
- Foods eaten
- Fluid intake
- Supplements
- Digestive symptoms
- Stool consistency
- Sleep quality
- Mood and energy levels
Over time, patterns may emerge that help identify areas for improvement.
Why Improving Gut Health Supports Fertility
Improving gut health supports fertility by:
- Enhancing nutrient absorption
- Supporting hormone balance
- Reducing inflammation
- Lowering oxidative stress
- Improving metabolic health
These factors create a more supportive environment for conception and reproductive health.
Conclusion
Gut health and fertility are closely connected through nutrient absorption, hormone regulation, inflammation and immune function. An unhealthy gut can affect fertility by disrupting these systems and contributing to hormonal imbalances, oxidative stress and chronic inflammation.
Common unhealthy gut symptoms such as bloating, constipation, irregular stool, fatigue and hormonal issues should not be ignored, especially when they persist over time. Recognising the signs of an unhealthy gut is an important step toward improving overall health and supporting fertility.
By increasing awareness of digestive health and understanding how the gut influences the body, individuals can take meaningful steps toward better gut health, improved hormone balance and stronger reproductive wellbeing.



















