Can your gut health affect your mental health?

Samantha Wild
Clinical Lead for Women's Health and Bupa GP
12 November 2019
Next review due November 2022

You may have noticed that gut health has become a really hot topic lately. From books to magazine articles, people seem to be paying more and more attention to the role our gastrointestinal system plays in our overall health. It’s thought that gut health can affect everything from mental wellbeing, to your risk of long-term conditions. Here I’ll explain what gut health means, what is meant by ‘good’ bacteria and how your gut and brain might be connected.

What is meant by gut health?

When you hear the term ‘gut health’, it’s referring to your digestive system, also known as your gastrointestinal (GI) tract. Your gut is where your body digests food, absorbs energy and nutrients, and gets rid of waste products. It goes all the way from your mouth to your back passage and also includes your throat, food pipe, stomach and intestines.

Your gut contains trillions of tiny bacteria and other microorganisms. In fact, there are more bacteria in your gut, than there are cells in your entire body. But unlike harmful bacteria that can make you ill or cause food to go off, the natural bacteria found in your gut are good for you. This is because they help to break down the food you eat, maintain the balance of bacteria in your gut and support your immune system to fight off other harmful germs.

You might also hear the bacteria in your gut referred to as good bacteria, friendly bacteria, gut flora, microorganisms, microbiota or microbes.

There are lots of things that can upset the balance of bacteria within your gut. For example, taking certain antibiotics, getting older, food poisoning or having a health condition such as irritable bowel syndrome (IBS) or inflammatory bowel disease. But one of the best things you can do to look after your gut is to eat well.

What are prebiotics and probiotics?

Prebiotics are a type of fibre that can’t be digested by your body, so they pass to your gut and feed the good bacteria there. Eating foods that contain prebiotics helps the good bacteria in your gut to grow. Prebiotics are found naturally in onions, garlic, asparagus, artichoke, chicory and bananas, and also available as a supplement.

Probiotics are ‘live’ microorganisms such as good bacteria and yeast. Eating foods that contain probiotics or taking a probiotic supplement helps to boost and balance the level of good bacteria in your gut.

You can find probiotics in some yoghurts and yoghurt drinks that contain live bacteria. They’re also present in fermented foods such as kefir, kombucha, kimchi, sauerkraut, miso and tempeh and available as supplements.

In some countries, dietary guidelines even recommend including probiotics as part of a healthy diet. But the European Food Safety Authority (EFSA) has banned labelling products as containing probiotics, so as not to imply that they benefit your health until more research has been done.

The mind-gut connection

To date, lots of the research on the effects of probiotics and gut health has focussed on specific gut conditions like IBS and inflammatory bowel disease. But more research is always ongoing, and findings suggests that the health of your gut could also have an impact on other systems in your body. For example, some studies have suggested that taking probiotics could reduce how long you have a cold for, while others have reported that they may help to you to fight off pollen allergies.

You may have also heard reports in the media claiming that your gut health could affect your mental health. This is a relatively new area of research, but what we do know, is that there is a link between your gut and your brain. This is sometimes known as the mind-gut connection, the brain-gut connection, or the gut-brain axis.

The communication between your gut and brain is thought to be a two-way street, involving your immune, hormone and nervous systems.

Have you ever heard of the saying ‘gut instinct’? Or began to feel sick when you’re anxious or upset? Your emotions and gut are often connected. Or perhaps you’ve felt pain in your stomach when you’re stressed? There is some evidence to show that chronic stress can disrupt the bacteria in your gut, cause inflammation and damage the wall of your intestine. Probiotics, however, may help to reverse this.

Just as your mind can influence your stomach, so can your stomach influence your mind. Gut problems such as bloating, indigestion, constipation and diarrhoea are naturally likely to make it harder for you to focus and may affect your concentration. You may feel worried or embarrassed or avoid certain situations where you might not be able to get to bathroom easily.

People with gut conditions like IBS or inflammatory bowel disease are more likely to be diagnosed with anxiety or other mental health conditions. But some studies have suggested that regulating your gut bacteria could influence your mood and may help to prevent and treat mental health conditions such as anxiety and depression.

There are many ways that our mind and gut can influence one another. But more evidence is needed before we can know for sure whether or not probiotics may be helpful in treating both gut and mental health conditions.

Should I take probiotics?

If you’re a healthy person of any age, taking probiotics is generally considered safe. But they may not be suitable for you if you have problems with your immune system.

Some research has suggested that taking the right amount of probiotics may be helpful if you:

  • are taking antibiotics as these can upset the balance of bacteria in your gut and sometimes cause diarrhoea
  • are travelling overseas to a country where food hygiene is poor and you’re at a higher risk of travellers’ diarrhoea
  • suffer from constipation
  • have irritable bowel syndrome (IBS)
  • have inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
  • have tummy pain, bloating or passing wind

Things to consider

  • There are lots of different types (known as strains) of good bacteria. And not all probiotics products or supplements are made or work in the same way. Different products will contain different types of bacteria in varying amounts.
  • When looking at the effects of probiotics on health, it’s difficult to know for sure which exact strain of bacteria may be responsible for having a positive impact on your health. Each single strain of bacteria needs to be tested individually before we can know for sure which ones may help certain conditions.
  • Not all probiotics survive the journey through your gut to be able to impact your health. Some are destroyed as they pass through your gastrointestinal (GI) tract, for example by your stomach acid. Those that do make it through may only live in your gut for a short while. So you have to take probiotics regularly to give them the best chance of reaching your intestines and influencing the environment there.
  • More research is also needed to find out how much of these probiotics you should take for them to have the optimum effect.

If you’re thinking of starting to take probiotics, you may need to trial different types to find the one that works for you. The strain that works for one condition, may not work for another. In general, it’s recommended to trial taking probiotics for four weeks, and if these don’t work for you, try another brand or stop taking them. Speak to your doctor or a dietitian for more advice.

If you’re worried about your mental health, our direct access service aims to provide you with the advice, support and treatment you need as quickly as possible. If you’re covered by your health insurance, you’ll be able to get mental health advice and support usually without the need for a GP referral. Learn more today.

Samantha Wild
Dr Samantha Wild
Clinical Lead for Women's Health and Bupa GP

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