There's been plenty of discussion in the media and health industry lately about prebiotics and probiotics. So, what exactly are they? In short, probiotics refer to the good bacteria or ‘microbiome’ found in your gut and prebiotics are the fuel source that feed these good bacteria.

The theory behind including more pre and probiotics in our diet is that they can help to improve the balance of good bacteria versus bad bacteria in our gut, which may have benefits to our overall health. Good bacteria kill and compete with harmful bacteria, which can produce toxic substances that can cause diarrhoea and infections.

However, it’s important to acknowledge that this is an emerging area of research and there’s still a lot that we don’t fully understand about this topic.


Probiotics are live, ‘friendly’ bacteria that can help to restore the balance of good bacteria in our gut. They can be found in your body right now, in certain foods and in the form of a supplement such as tablets, capsules, or sachets.

Probiotics found in food are called ‘live cultures’. Foods that contain live cultures include yoghurt, soft cheese, and fermented foods like kimchi, sauerkraut (cabbage), tempeh (fermented soybeans), kombucha, and kefir (fermented milk beverage).

It may be beneficial for your gut health to include these foods in your diet, but there’s not enough research yet to suggest that these foods will cure any conditions such as irritable bowel syndrome (IBS).

All fermented foods have a different mix of bacteria that might be beneficial, so you could experiment by adding a range of these foods to your diet. Kimchi and sauerkraut add a tangy flavour to a sandwich and kombucha (without added sugar) can be a great alternative to an alcoholic drink or fizzy drink.

It's important to keep in mind that some of these fermented foods (e.g. kimchi and sauerkraut) can also be very high in salt, so be mindful of this when adding to meals.

Should I take a probiotic supplement?

The average healthy person doesn’t need a probiotic supplement to have a healthy gut. There's research to suggest there are certain conditions when a probiotic supplement can be beneficial, for example throughout a course of antibiotics to help reduce the risk of antibiotic associated diarrhoea, or when travelling abroad to lower the risk of traveller’s diarrhoea.

If you do choose to take a probiotic supplement for a particular purpose, it can be really confusing knowing which one is best. There are hundreds of different strains and doses of probiotic supplements out there. It’s important you select the strain of probiotic that's been proven to be beneficial for that particular condition in clinical trials. We'd suggest discussing this with your GP.

As we mentioned before, there's still so much we don’t know about the role of our gut microbiome and the ways in which our lifestyle choices can affect our gut health. Each individual’s gut microbiome can also vary greatly, so it's difficult to make assumptions from person to person. Our own gut microbiomes change all the time in response to things like diet, stress, and environment (e.g. smoking, pollution, and hygiene).


Prebiotics are the food that the good bacteria (probiotics) eat and can help the good bacteria to grow in your gut. They're a type of carbohydrate that we can't digest, which is found in lots of plant-based foods.

Some examples of prebiotic containing foods include lentils, pulses, onions, asparagus, artichoke, chicory root, garlic, leeks, wheat bran, oats, apples, and bananas.

What about prebiotic supplements? You should be getting enough prebiotics by having a variety of plant-based foods, so prebiotic supplements aren’t necessary if you’re having a balanced, varied diet.

Some people with IBS can be sensitive to some prebiotics. It's often dose dependent, meaning that eating a large amount of them may cause IBS symptoms in those that have the condition, but a smaller amount might be tolerated. Before cutting these foods out of your diet completely, it's best to discuss this with your GP or Registered Dietitian that specialises in digestive health.

Key points:

  • Prebiotics and probiotics are an emerging area of research and we’re still learning about their effect on our health
  • It may be beneficial for your gut health to include foods containing prebiotics and probiotics (live cultures) in your diet such as fermented foods and plant-based foods like onions and garlic
  • If you’re including a variety of foods in your diet, you don’t need to be taking a probiotic or prebiotic supplement to have a healthy gut
Did this answer your question?