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What are probiotics?

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Probiotics are foods and food supplements that contain live bacteria thought to be beneficial for gut health. Our digestive system is home to all kinds of “good” bacteria. By consuming probiotics that contain these good bacteria, it’s possible to support your gut health.

Probiotics tend to contain one of two types of bacteria: lactic acid bacteria (LAB) or bifidobacteria. Lactic acid bacteria is commonly used in fermented foods like yoghurt.

What are some good sources of probiotics?


In the supermarket, the most readily available products containing probiotics are yoghurts and yoghurt drinks. These tend to be popular because they’re really easy to incorporate into your lifestyle. Yoghurt with fresh fruit can be a great breakfast food, dessert, or afternoon snack.

Other foods

Probiotics can be found in a number of fermented foods i.e. foods that have had bacteria added to them. Simply adding these kinds of foods to your diet could help you get more good bacteria in your gut:

  • Kefir – a fermented milk drink
  • Tempeh – a fermented soybean product
  • Kimchi – salted and fermented vegetables, normally radish or cabbage
  • Kombucha – fermented black or green tea
  • Miso – Japanese seasoning made from fermented soybeans
  • Natto – fermented soybeans
  • Sauerkraut – fermented cabbage

Soft and/or aged cheese, and green olives are also good sources of probiotics.

Just remember: a healthy diet is one that is balanced, varied, and includes lots of carbohydrates and fruits and vegetables. For more guidance on following a healthy diet read our guide.

Food supplements

If you think you might struggle to get probiotic-rich foods into your diet, another option is to buy food supplements from your local pharmacy or health food shop.

Probiotic supplements tend to come in capsule, tablet, or chew form, or sometimes as a powder.

Popular brands include:

The NHS recommends taking probiotic supplements, or an equivalent product like a yoghurt, every day for four weeks to see if there’s any effect on your gut health.

What are the potential benefits of probiotics?

Probiotics are thought to have a few different benefits for the body. If you’ve been ill or had a treatment that’s affected your gut, it’s thought that taking probiotics can help restore normal gut health.

For example, the NHS advises that probiotics can be helpful for easing the symptoms of irritable bowel syndrome, and can prevent diarrhoea when you’re taking antibiotics – you can learn more about this in the sections below.

More generally, probiotics are thought to do the following:

  • Increase the amount of “good” bacteria (i.e. healthy organisms) in your gut
  • Reduce the amount of “bad” bacteria
  • Strengthen the digestive system against harmful substances
  • Reduce inflammation in the gut

Probiotics for IBS

IBS causes stomach pain and cramps, bloating, and diarrhoea or constipation. Symptoms are often triggered by alcohol, caffeine, spicy and fatty foods, and stress and anxiety.

If you think you have irritable bowel syndrome, you should visit your GP. They may suggest trying probiotics to ease the symptoms described above. You can also read our symptoms guide here.

Probiotics when you’re taking antibiotics

Taking antibiotics can strip out the good bacteria from your gut, allowing bad bacteria to thrive. This is why antibiotics can sometimes cause diarrhoea. If you have to take antibiotics, your GP may recommend trying probiotics to help you avoid getting an upset stomach.

Are probiotics safe and effective?

Probiotics tend to be classed as a food or food supplement, rather than a medicine. This means that they aren’t regulated in the same strict ways as medicines, and that it’s not always easy to tell what a product contains. 

In the context of a clinical study, probiotics can be an effective treatment for gut problems. In practice, however, a product you find in a health food shop or supermarket may not contain enough bacteria, or the right kind of bacteria to make a difference.

However, as explained on this page, the NHS considers probiotics safe for people with a healthy immune system. If you aren’t sure whether probiotics are right for you, it’s a good idea to speak to your GP first.