Friday, March 1, 2024

Gut health guide

The body is home to trillions of bacteria and other microbes that play a crucial role in keeping us healthy. Nowhere is this more beneficial than in the gut, which has more microbes than anywhere else in the body.

Gut health and the microbiome

This clever internal ecosystem is dubbed the ‘microbiome’. A healthy microbiome helps to keep digestion, immune function and weight regulation in order and can weigh up to five pounds. Lots of factors impact the health of the gut, but positive lifestyle choices are vital if you want to keep this precious bacteria in balance.

People with higher levels of certain bad bacteria are more likely to suffer from gut health problems, from stomach upsets and bowel problems to more serious conditions like Crohn’s disease, ulcerative colitis and irritable bowel syndrome (IBS).

In this guide

What is gut health?

There’s still lots to learn about the microbiome, but experts believe that certain environments, foods and lifestyle factors can have an impact on our gut health. Microbes are constantly adapting, and factors like stress, diet, age, gender and everything we touch can alter the composition of our gut bacteria.

A healthy gut contains a diverse range of organisms – mostly bacteria, but also viruses, fungi and other microbes. These may not sound too pleasant, but they’re critical when it comes to many elements of our wellbeing. When there’s a lack of diversity, it can lead to an unhealthy gut, causing inflammation and certain gut health problems – medically known as dysbiosis.

Gut bacteria is finely tuned to play a dual role in both fighting and promoting inflammation. When the microbiome is healthy, these roles are kept in equilibrium – but when they’re out of balance the inflammatory bacteria can take over and even spread inflammation to other parts of the body.

Gut health advice

Gut health facts and figures

  • The gut ecosystem is home to trillions of bacteria, viruses and fungi, which can weight up to five pounds.
  • A healthy gut contains a diverse range of organisms – a lack of diversity can lead to certain gut health problems such as bloating, gas, diarrhoea and stomach pain.
  • When the microbiome is out of balance it can have an effect on your immune system and make it harder to fight off infection.
  • Antibiotics can cause disruption to your gut health, but with the right diet and lifestyle it’s possible to nurture a happy and healthy gut.

Why is gut health important?

What’s remarkable about the gut is its ability to influence nearly every function of the human body in some way.

Healthy digestive system

The bacteria that live in the stomach are vital in preventing issues with the gastrointestinal tract and maintaining an effective digestive system.

If the microbiome is thrown out of balance, you’re likely to feel it through your digestive system. Bloating, gas, diarrhoea, stomach pain and nausea are all clear indicators that the gut isn’t working as well as it should. In more serious cases, gut health effects can be seen in conditions like Crohn’s disease, ulcerative colitis and IBS.

The rest of the body

When the gut’s delicate ecosystem isn’t in harmony it can have far-reaching effects. Your general health can take a dive and be less able to fight off illness, as your immune system struggles to function effectively.

Longer term, a lack of diversity in the microbiome may have more serious consequences. Specific types of bacteria have been linked with a lower incidence of cancer, heart disease, liver disease, diabetes, asthma and many allergies.

Brain, mood and behaviour

The gut is home to 100 million neurons, which is why it’s sometimes dubbed ‘the second brain’. Researchers believe this enables our gut to ‘talk back’ to our brain, which could impact mood and influence behaviour.

This link has led scientists to suspect that changes in the microbiome’s balance may play a role in mental health conditions like anxiety and depression and even have a connection with autism.

Gut health in numbers

  • The gut is home to 100 million neurons which may enable our gut to ‘talk back’ to our brain, impacting mood and influencing behaviour.
  • Probiotics may play a role in as much as 80% of our body's immune response, according to research.

Signs of gut health problems

Bad gut health can cause a range of symptoms including:

  • Changes in bowel habits – constipation and diarrhoea can be one of the first obvious symptoms. Everyone’s movements vary, so get to know what’s normal for you.
  • Stomach upsets – gas, bloating and heartburn are all signs that the gut is out of balance.
  • Skin problems – irritated skin, rashes and eczema can all be linked to ‘leaking’ of proteins into the body as a result of inflammation in the gut.
  • Bad breath – a metallic taste in your mouth and bad breath could be a result of an imbalance in your gut’s bacteria.
  • Feeling sluggish – when the gut is out of synch it can cause toxins and waste to build up, making us feel tired and sluggish.
  • Trouble sleeping – the gut produces most of our serotonin (a hormone that affects mood and sleep), so when it’s damaged it can have a knock-on effect on our quality of sleep.
  • Weight changes – the gut helps to absorb nutrients, regulate blood sugar and store fat. So, if you’ve lost or gained weight without making any changes to your diet or exercise regime, your gut could be to blame.

How to tell if your gut is healthy

There are a number of ways to find out more about what’s going on in your gut:

Home testing kits – many home gut health tests are available, but the jury is still out on how helpful they are. Most involve sending off a stool sample for analysis. You’ll receive information about the types of microbes in your gut and advice on how to improve your wellbeing through diet, supplements and lifestyle changes.

Medical tests – it’s uncommon for doctors to test for gut health. Instead, they are likely to take a stool sample to see if it contains blood or parasites. They may refer you to a digestive specialist such as a gastroenterologist for further evaluation, or recommend procedures such as a colonoscopy, a sigmoidoscopy or an ultrasound.

Microbiome testing – to map out the health of your microbiome with a professional, you’ll need to go to a private gut health clinic for testing such as the GI-map stool test or a Small Intestinal Bacterial overgrowth (SIBO) test.

When to see your doctor

It’s time to see your doctor if symptoms persist for more than a few days and start to affect your day-to-day life. Always see your doctor immediately if you notice blood in your stools.

Gut health diet

What affects gut health?

We all have a unique microbiome, some of which is predetermined at birth, but our environment and lifestyle also affect how it develops.

How to improve gut health

Gut health diet – what we eat feeds the community of bacteria in our gut, so look after it with a diet rich in plant-based food, fibre and low in sugar and processed food. Our microbiome loves probiotic foods as they help boost the diversity of microbes.

Lifestyle – we know that stress and lack of sleep can affect gut health. Try to make positive lifestyle choices like exercising regularly, staying social, cutting down on caffeine and alcohol, reducing screen time and getting regular bedtimes.

Medication – antibiotics can play havoc with the equilibrium of bacteria in the gut. As well as killing the ‘bad’ bacteria they can also wipe out the good. Pay attention to your diet if you’re taking antibiotics to help keep the balance in check.


This is a term you’re probably familiar with, thanks to the huge range of ‘probiotic’ drinks and yoghurts available. But it’s not just branded products that contain probiotics.

What are probiotics?

Probiotics are ‘friendly’ bacteria that live naturally in many foods and help to prevent the bad bacteria from setting up home in your gut. There’s evidence to show that they can improve symptoms in IBS and diarrhoea and could even make a difference to cold and flu outcomes.

Types of probiotic food

Probiotics occur naturally in food such as yogurt, tempeh (soy product), sauerkraut, kefir (fermented milk drink), kombucha and miso. There are also a range of supplements available.


Prebiotics may not be as well known as probiotics, but they are just as important when it comes to gut health.

What are prebiotics?

They often exist in starchy foods that are laden with complex carbohydrates. As they can’t be digested by our body, they remain in the stomach and pass through to the digestive tract. Then the magic happens, as they feed existing gut bacteria and microbes, encouraging them to thrive and grow.

Types of prebiotic food

There are many different types of prebiotic foods and it’s worth eating a wide range of them to encourage a healthy gut. These include onions, garlic, leeks, apples, bananas, oats and asparagus. Read our guide on prebiotic foods to boost wellness for more detailed advice.

Should you take probiotic or prebiotic supplements?

There are a range of supplements available, each designed to treat different symptoms, so it’s a good idea to do some research before deciding.

Popular prebiotic supplements include ‘fructooligosacharides’ (FOS) and inulin which both help to promote the size, diversity and function of our gut bacteria.

When choosing a probiotic, make sure it contains enough bacteria (107 to 1010 probiotic cells per gram) to have an effect. It’s also important that it can survive the stomach’s acidic environment in order to reach the large intestine, such as Alforex, Yakult, Symprove and VSL #3.

Did you know?

There are many more probiotics in your gut than there are cells in your body. An average person has around 10 trillion probiotic yeast and bacteria in their stomach compared to just 1 trillion cells in the human body. Food for thought!