Gut health


Gut health – fact versus fiction

31 January 2024

The gut is an incredibly complex system, which does a lot more than just digest our food. It’s connected to almost every bodily function and is central to our overall physical and mental health.

The ‘gut’ refers to your gastrointestinal (GI) system – the stomach, large and small intestines. The GI system contains trillions of bacteria and other microbes, collectively known as the gut microbiota. Some types of bacteria are bad for us, but a lot of them are ‘friendly’ and essential to our health.

This good bacteria grows and develops throughout our lives, interacting with the body and controlling food digestion and impacting many other bodily processes.

Various studies have linked the gut to:

  • the immune system
  • mental health
  • certain cancers
  • cardiovascular disease (including cholesterol)
  • type 2 diabetes
  • gastrointestinal disorders
  • autoimmune diseases.

It’s also thought that up to 95% of our serotonin – a chemical that is key to regulating our mood, sleep, digestion, recovery and musculoskeletal health – is created within the gut.1

So, while a healthy diet is crucial, it’s not the only thing we need to consider when it comes to gut health.

Myth busters

To properly look after your gut health, it’s important to have all the facts and let go of any misconceptions. So, let’s start by debunking a few common myths about gut health.

MYTH - gut health is only determined by what you eat

Food is integral to a healthy gut, but there are many other variables that can impact or damage the delicate balance of your gut microbiota. The gut is intrinsically linked to the brain, so stress can severely impact digestion and alter the delicate balance of good bacteria. Sleep, medication, exercise and genetics can also affect this balance and impact your overall gut health.

MYTH - everyone’s gut is the same

No, in fact, everyone’s gut is different. Our bowel habits, rate of digestion, hormone levels and bacteria balance are all unique as they depend on countless different day-to-day variables like hydration, sleep and stress. So, not all guts are the same and there’s no one-size-fits-all approach to gut health.

MYTH - gluten and dairy are bad for gut health

This is a very common misconception. Unless you suffer from coeliac disease, which affects 1% of the entire population,2 or you’re lactose intolerant or have a dairy allergy, both gluten and dairy can be an essential part of a balanced diet.

A varied diet is key for diverse and healthy gut bacteria, so cutting out entire food groups is rarely necessary unless you’ve been advised to do so by a healthcare professional. For example, a lot of gluten-rich foods contain fibre, which is essential to gut health, while dairy is a great source of protein and minerals.

MYTH - gut health is only important for digestion

A healthy gut is vital for digestion, yes. But, just as gut health can be affected by other factors, the gut itself controls more than just digestion. The brain and gut are connected, and recent studies have found that it’s a two-way street.

That means poor gut health can affect our mental health, sleeping patterns, energy levels and immune system.

MYTH - a detox or colonic irrigation can restore gut health

This is another common misconception. The truth is that both detoxes and colonic irrigation can actually damage your gut health unless they’ve been specifically prescribed by a doctor.

Detoxes usually involve extreme dietary restrictions, which literally starve the gut of the variation it needs to keep healthy. Meanwhile colonic irrigation can damage the balance within the gut by washing away good bacteria, causing dehydration and even damaging the lining of the bowel.

What causes an unhealthy gut?

Poor gut health is caused when there’s a disruption to the balance or the health of the good bacteria in the gut. And, as the gut is connected to various bodily functions, it can be negatively affected by all kinds of different factors, including:

Stress – Stress hormones can slow down or speed up digestion. Stress also affects our appetite and can cause us to eat more unhealthy foods, making it harder for good bacteria to thrive.3

Smoking – Tobacco smoke contains harmful chemicals that can damage almost any organ within the body. It can cause acid reflux, inflammatory bowel disease (IBD) and an imbalance of healthy bacteria within the gut.

Poor diet – A healthy gut needs a rich and diverse range of gut bacteria. The food we eat provides us with nutrients that help this bacteria grow. So, a diverse and healthy diet means diverse and healthy gut bacteria.

Not eating right – It’s not just about what we eat. We also need to think about how we eat. Not chewing food properly, rushing meals, skipping meals or eating at strange times can all negatively impact gut bacteria.

Drinking too much alcohol – Too much alcohol can have a profound effect on our physical and mental health. It can cause an imbalance between good and bad gut bacteria, which can lead to weight gain, inflammation and diabetes.

Poor sleep – Good sleep is vital to our overall health. It enables us to recharge, both physically and mentally, and regulates our hormones and other bodily functions. Poor sleep can disrupt the balance within your gut and have a harmful effect on gut bacteria.

Lack of exercise – Exercise and physical activity are vital to our overall health. Being active helps reduce stress, prevent obesity and lower the risk of some diseases. It also promotes the production and abundance of healthy gut bacteria.

What’s your gut telling you?

Maintaining gut health can be a delicate balancing act, and it might not be easy to tell if there’s an issue. But there are a number of common signs and symptoms that could indicate an unhealthy gut.

1) Bloating, gas and stomach pain can be caused by food intolerances, which are linked to the gut bacteria not being able to break down certain types of food properly.

2) Weight fluctuations can also be an indication of poor gut health. We need a healthy gut to break down food, extract nutrients and regulate our metabolism. Unexpected weight loss or weight gain can therefore be a sign of an unhealthy gut.

3) Skin issues, including acne, rosacea, eczema, psoriasis and dandruff, can be caused or affected by an imbalance in gut bacteria.

4) Irritability, poor concentration or low mood are also very common symptoms of poor gut health. The gut and the brain are connected, and the digestive system produces serotonin, which plays an important role in our mood.

So, a vicious cycle can develop where poor gut health causes mental health issues and vice versa.

5) Fatigue or insomnia are also indicators of poor gut health. Issues with the digestive system can disrupt your circadian rhythm (sleeping cycle) which impacts the quality of your sleep and can lead to insomnia and fatigue. At the same time, gut issues can also mean fewer nutrients are extracted from your food, which can be another cause of fatigue as energy levels become depleted.

Poor gut health and imbalances in the levels of good bacteria can be linked to serious and chronic issues, including:

  • diabetes,
  • obesity,
  • inflammatory bowel disease
  • and colorectal cancer.

So, it’s important to pay attention to what your gut’s telling you by looking out for these symptoms and doing all you can to maintain your good bacteria.

What can I do to keep my gut healthy?

Maintaining a healthy gut relies on healthy habits and ongoing efforts. There isn’t always a quick fix and, if you’re suffering from poor gut health, you may find that improvements are gradual.

To look after or improve your gut health, try to focus on…

What you eat – Your diet is integral to the health of your gut microbiota. Try and eat home-cooked or freshly prepared meals as often as possible and use fresh ingredients wherever you can.

Fibre-rich and plant-based foods are particularly good for the gut, while processed foods, fast food and anything that’s high in saturated or trans fats can have a negative effect. The diversity and health of gut bacteria depends on a varied and balanced diet, so try not to eat the same foods every day.

>Discover some of our recipes for some home-cooked inspiration

Staying hydrated – Drinking plenty of water is essential to your overall health. It’s also a very important and a very simple way to help improve digestion, reduce the risk of constipation, and encourage diversity of gut bacteria.

Other drinks can help hydrate you, but it’s worth noting that fizzy drinks, artificially sweetened drinks, caffeine or anything with a lot of added sugar can cause inflammation and have a negative impact on gut bacteria.

Healthy choices – Smoking and drinking too much alcohol both have a significant impact on gut health. Too much alcohol adds to stress levels and causes inflammation in the gut, while smoking can damage the muscles and lining of the digestive system and is a risk factor for stomach cancer.

Only consuming alcohol in moderation, avoiding binge drinking and not smoking will all help when it comes to maintaining a healthy gut.

>Find out more on how to keep your gut healthy

While all these tips and suggestions can help with maintaining a healthy gut, it’s important to see a GP if you’re worried, or if you’ve been suffering with severe or prologued symptoms.

Digestive problems and the symptoms listed above can be linked to food intolerances and issues like coeliac disease and Crohn's & Colitis, so it’s worth monitoring your situation and speaking to a healthcare professional if you’re unsure about anything.


  1. Let’s talk about digestive health - Guts UK / Imodium
  2. Coeliac disease overview - NHS
  3. Stress, depression, diet, and the gut microbiota - National Library of Medicine