How to Recognise the Signs of an Unhealthy Gut

Your gut is home to trillions of microorganisms that together form the gut microbiome. These microorganisms interact with your digestive system and play a role in processes ranging from breaking down certain foods to supporting normal immune function.

But how can you recognise the signs of an unhealthy gut? Digestive symptoms such as persistent bloating, constipation, diarrhoea or abdominal discomfort can indicate that something in your digestive system needs attention. However, these symptoms can have many different causes and cannot tell you exactly what is happening in your microbiome.

Here are some common signs to look out for, factors that can influence your gut microbiome and practical ways to support your digestive health.

What Is the Gut Microbiome?

The gut microbiome is the community of bacteria, fungi, viruses and other microorganisms living primarily in your large intestine.

Rather than simply dividing these microorganisms into "good" and "bad" bacteria, researchers increasingly look at the microbiome as a complex ecosystem. Its composition differs considerably from one person to another and can change in response to diet, medication, lifestyle and other factors.

Gut microorganisms perform several important functions. For example, some bacteria help break down dietary components that our own digestive enzymes cannot fully process, particularly certain types of fibre.

During this process, gut bacteria can produce compounds such as short-chain fatty acids. The gut also interacts closely with the immune system and the intestinal barrier.

What Does an Unhealthy Gut Mean?

There is no single definition of an "unhealthy gut microbiome". Scientists sometimes use the term dysbiosis to describe changes in the composition or function of the microbial community that are associated with certain health conditions.

Importantly, there is currently no universal microbiome profile that defines a perfectly healthy gut for everyone.

For everyday health, it is therefore often more useful to pay attention to your digestive function, diet and persistent symptoms rather than trying to identify an ideal combination of gut bacteria.

What Are Common Signs of an Unhealthy Gut?

Digestive symptoms are among the most obvious signs that your gastrointestinal system may need attention.

Common symptoms can include:

• Frequent or persistent bloating
• Excessive gas
• Abdominal discomfort or pain
• Constipation
• Diarrhoea
• Changes in bowel habits
• Nausea
• Discomfort after eating certain foods

Occasional digestive discomfort is common and does not necessarily mean that something is wrong with your microbiome.

However, symptoms that are persistent, severe or significantly affect your daily life should be discussed with a healthcare professional.

Can an Unhealthy Gut Cause Symptoms Outside the Digestive System?

The gut interacts with several systems throughout the body, including the immune and nervous systems. This has led to growing scientific interest in connections such as the gut-brain axis and gut-skin axis.

However, symptoms such as fatigue, changes in mood, skin problems or poor sleep are not reliable indicators of an unhealthy microbiome on their own. They can have many possible causes.

Rather than assuming that every unexplained symptom starts in the gut, consider your overall health and seek professional advice when symptoms persist.

What Can Affect Your Gut Microbiome?

Your gut microbiome is dynamic and can be influenced by many different factors.

Diet

What you eat provides nutrients not only for you, but also for the microorganisms living in your gut.

A varied diet containing different plant foods and sources of fibre provides substrates that gut bacteria can ferment. Dietary patterns can therefore influence the composition and activity of the gut microbiome.

Antibiotics and Other Medications

Antibiotics are designed to treat bacterial infections, but they can also affect other bacteria living in the gut.

Changes to the microbiome following antibiotic treatment can vary depending on the antibiotic, treatment duration and individual person.

Antibiotics should always be taken according to medical advice and should not be avoided when they are medically necessary.

Lifestyle

Sleep, physical activity, stress and other lifestyle factors may also interact with digestive health and the gut microbiome.

Rather than focusing on one isolated factor, supporting your general health through consistent everyday habits is a practical place to start.

How Can You Support a Healthy Gut?

You do not need an extreme diet or complicated "gut reset" to support digestive health. Start with the foundations.

1. Eat a Variety of Fibre-Rich Foods

Dietary fibre is found in plant foods and plays an important role in normal digestive function.

Good sources include:

• Vegetables
• Fruit
• Whole grains
• Beans and lentils
• Nuts and seeds

Different plant foods contain different types of fibre, so variety can be particularly useful.

2. Include Prebiotic Foods

Prebiotics are substrates that are selectively used by microorganisms in the body and can provide a health benefit.

Certain types of fermentable fibre occur naturally in foods such as:

• Onions
• Garlic
• Leeks
• Oats
• Bananas
• Legumes

If you are not accustomed to eating much fibre, increasing your intake gradually can help your digestive system adapt.

3. Include Fermented Foods

Fermented foods can add variety to your diet and some contain live microorganisms.

Examples include:

• Yoghurt with live cultures
• Kefir
• Sauerkraut
• Kimchi

Not every fermented food contains live microorganisms by the time you eat it, so fermented and probiotic are not necessarily the same thing.

4. Stay Hydrated

Fluid intake is another important part of normal digestive function, particularly when you are increasing your fibre intake.

Water needs vary between individuals and can depend on factors such as physical activity, climate and diet.

5. Stay Physically Active

Regular movement supports general health and normal digestive function.

This does not need to mean intense exercise every day. Walking, cycling, swimming and other activities you enjoy can all become part of a healthy routine.

Can Probiotics Support Gut Health?

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.

However, probiotics are not all interchangeable. Different products contain different microorganisms, strains and quantities, and their effects can be strain-specific.

This means that simply having a high number of strains or bacteria does not automatically make one probiotic better than another.

If you choose a probiotic supplement, look carefully at which microorganisms it contains and follow the recommended use of the specific product.

When Should You Speak to a Healthcare Professional?

Digestive symptoms are common, but persistent problems should not automatically be blamed on your gut microbiome.

Speak with a healthcare professional if you experience ongoing or concerning symptoms, particularly:

• Persistent abdominal pain
• Long-lasting diarrhoea or constipation
• Blood in your stool
• Unexplained weight loss
• Persistent vomiting
• Significant changes in your bowel habits

These symptoms can have many possible causes and may require appropriate medical assessment.

Support Your Gut With Consistent Habits

There is no single sign, food or supplement that defines a healthy gut. Your digestive health is influenced by your diet, lifestyle, medications and many individual factors.

Instead of trying to create a "perfect" microbiome, focus on habits that support your overall digestive health: eat a varied diet rich in fibre, include different plant foods, stay hydrated, move regularly and pay attention to persistent changes in how your digestive system feels.

Small, consistent habits can help create a strong foundation for long-term gut health.