Gut health: What are probiotics and how can they help?

Sarah Tipping
Dietetic Assistant (Associate Registered Nutritionist), Cromwell Hospital
17 October 2018

Do you ever have a bloated stomach or tummy pain and not sure why? It could be due to the balance of the bacteria in your gut. This balance may be affected by the food that you eat, but here we look at the impact of probiotics and how these may help promote a healthy gut.

About your gut

The gastrointestinal tract, also known as your gut, is an organ system which takes in food in order to digest and absorb energy and nutrients. It also removes waste products such as urine. Your gut contains a large number of different strains of bacteria and other microorganisms (such as yeast) called the gut flora. These include viruses and bacteria, which all play a part in supporting your immune system to work correctly.

Creating a healthy environment in your gut can have positive effects on your health. For example, some research indicates it can help reduce how long you have a cold for. Your gut is extremely sensitive and an imbalance of its gut flora can lead to discomfort; for example, bloating and tummy pain. In some people it means they are unable to absorb certain nutrients.

So, where do probiotics come into this? What are probiotics?

Probiotics contain a large number of friendly bacteria and other microorganisms. Probiotics are live ‘good’ bacteria, which contributes to a healthier environment in your gut. There are also prebiotics, which are the food for the good bacteria. Both prebiotics and probiotics are found naturally in the following foods.

  • Prebiotics: garlic, onions, artichokes, leeks, asparagus and leeks.
  • Probiotics: some yoghurts (must say live cultures included), kimchi (fermented cabbage), kefir (fermented milk drink) and kombucha (fermented sweet tea).

You can also take prebiotics and probiotics as a supplement.

What are the benefits of probiotics?

In the right amounts, research has suggested probiotics can have positive effects on our health, though in some instances more research is needed. Much of the research into probiotics has focused on specific gut health conditions, including the following.

Bloating and tummy discomfort in healthy people

Some research suggests probiotics can help ease the symptoms of bloating and mild tummy ache in otherwise healthy people. They can also help soften hard stools.

Diarrhoea from a tummy bug

Studies have shown that probiotics might shorten the time of having diarrhoea from a stomach bug. It might also improve symptoms too.

Traveller’s diarrhoea

Probiotics can reduce your risk of getting traveller’s diarrhoea when you’re abroad.

Irritable bowel syndrome (IBS)

Probiotics may improve symptoms of IBS. Guidelines also recommend that patients who want to take probiotics should take them for at least four weeks and at the stated dose by the manufacturer.


Some research has shown probiotics can help improve constipation in elderly people.

Ulcerative colitis

Probiotics might help with ulcerative colitis, a condition in which your large bowel becomes inflamed and develops ulcers. However, more research needs to be done.

Crohn’s disease

Crohn’s disease is a condition where any part of your gastrointestinal tract can become inflamed. The research, to date, shows there is little benefit in helping this condition and more research is needed.

Diverticular disease

Some research has shown that probiotics may improve the symptoms of what’s called uncomplicated diverticular disease, a condition that affects your large bowel.

If you have a specific health condition it’s best to talk to your doctor about whether probiotics could help you.

So should I include probiotics in my diet?

You can include probiotics in your diet; people have been eating and drinking them safely for thousands of years. But there are a few things to bear in mind.

  • Not all probiotics are the same. There are lots of different strains of bacteria, which mean that some of the health effects may be specific to a single strain of bacteria. This can make it quite tricky to confirm the benefits, as a single strain of bacteria would need to be tested for each and every health outcome. For example, if a specific strain was found to ease IBS symptoms, it would be misleading to say that all probiotics help with IBS symptoms.
  • Getting the right amount is important. Probiotics need to be taken on a regular basis in the right dose to be effective (for at least four weeks). This is so they can survive the harsh journey to your gut (stomach acid makes it hard for them to survive).
  • Probiotics aren’t suitable for everyone. Probiotics are safe for most people but there’s a very small risk of sepsis for some people. Probiotics aren’t advised if you have a weakened immune system or after surgery, for example.
  • There’s no clear advice or specific guidelines on taking probiotics generally. While you can buy probiotics widely in various forms (food, powders, capsules etc), experts aren’t yet able to give specific advice on what you should take to make a difference to your health.

What’s our verdict?

So, with the mounting evidence, I’d say for a person with a healthy immune system, probiotics shouldn’t cause any unpleasant side-effects and may benefit your tummy health. And, with building evidence showing the benefits of these types of foods, this may be a great time to try something new in your diet! If you’d like to have a go at making your own probiotic-rich drink, take a look at the recipe below.

Homemade kefir recipe

What you’ll need:

  • 500ml full-fat milk
  • one tablespoon of kefir grains (you can get these in most large supermarkets)
  • fruit of your choice (try to choose fruits which are in season)


  • Pour the milk into a glass jar and add the kefir grains.
  • Cover the jar/glass with some cling film and leave out at room temperature (away from sunlight) for around 24 hours.
  • Taste the kefir often to see how the flavour changes over time. After 24 hours, strain out the kefir grains into a glass using a funnel and a sieve.
  • Chop and add your chosen fruit to the milk kefir.
  • Once you’re happy with the taste of the kefir, it’s ready to enjoy!
  • The kefir can be stored in the fridge for up to a week, as long as the lid is closed tight.

Even healthy people become unwell sometimes. Health insurance can help you get prompt access to the treatment and support you need to help you get back on the road to recovery. Learn more with our useful guide to understanding health insurance.

Sarah Tipping
Sarah Tipping
Dietetic Assistant (Associate Registered Nutritionist), Cromwell Hospital