Prebiotics and Probiotics Explained

4th September 2018 / Health

Prebiotics and Probiotics Explained

Laura Tilt

Pre And Probiotics Explained


If you’re interested in gut health, you’ve probably heard the words pre and probiotics – but what do they mean, and why do they matter to our digestive wellbeing?


To make sense of prebiotics and probiotics, we first need to take a journey into your gut. Stretching almost 8 metres in length, your gut is home to an impressive 40 trillion (or so) bacteria. Together with the genes they instruct, these bacteria are collectively known as your microbiome.


The work of your gut bacteria


You probably don’t spend much time thinking about the families of bacteria living in your gut, but behind the scenes these little guys are busy protecting your health.


One of the most important jobs of your gut bacteria is defending against illness. Helpful bacteria lining your gut form a physical barrier, stopping harmful bacteria from invading your inner world. They also turn the fibre you eat into anti-inflammatory compounds, and manufacture B vitamins, which turn food into energy.   


Although your microbiome is fairly stable, it’s not immune to changes. Diet and exercise habits, antibiotic use and even stress levels can all affect the number and types of bacteria in your gut.


This is significant because changes in the microbiome seem to affect the risk of developing different diseases1. For example, changes in gut bacteria may be a trigger for IBS (irritable bowel syndrome), which can lead to symptoms like gas, bloating and tummy pain.


One thing is clear - taking care of your gut bacteria is important – and this is where pre and probiotics can play a role.


The role of probiotics and prebiotics


Probiotics are types of live bacteria – similar to the ones already living our guts. If consumed in sufficient numbers, they can benefit our health. They can help when our own gut bacteria are under pressure – when travelling, because of a poor diet, or due to antibiotic use. Probiotics can be consumed in foods (like yoghurt and cheese) or supplements, which contain various strains and doses of helpful bacteria.


Prebiotics aren’t live bacteria – they’re ingredients which feed your resident bacteria, encouraging them to multiply2. Prebiotics are mostly types of dietary fibre – they can be found in various foods (like onions, garlic, leek and oats) or taken as a supplement.


Both pre and probiotics are important because they have different effects on the gut. As probiotics pass through your digestive system, they interact with various cells, triggering helpful changes. However, they don’t necessarily increase the numbers of good bacteria on a long-term basis. This is the job of prebiotics, which encourage growth by providing food for the bacteria.


When consumed together, pre and probiotics have what we call a ‘symbiotic’ effect – they work together to balance the bacteria in your gut. Choosing to include both pre and probiotics in your diet is therefore a helpful move towards maintaining a beneficial balance in your gut’s flourishing garden.






  1. Enck P, Mazurak N. Dysbiosis in Functional Bowel Disorders. Ann. Nutr. Metab. 2018:296-306. doi:10.1159/000488773.
  2. Sanders ME, Merenstein D, Merrifield CA, Hutkins R. Probiotics for human use. Nutr. Bull. 2018;43(3):212-225. doi:10.1111/nbu.12334.


Link Nutrition's Synbiotic 7 contains both a prebiotic and 7 probiotic strands.

About the Author

Laura is a UK Registered Dietitian, health writer and columnist for Women’s Health Magazine. With ten years of experience in nutrition science, Laura is passionate about helping others understand the relationship between what goes on their plate and what happens in their bodies.