Confused by the concepts of prebiotics and probiotics? Don’t worry you are not alone! Understanding the distinction between these is incredibly important, especially if you are looking to optimise your health or address ongoing health concerns. So let’s unpack it.

I really like the analogy of a garden.


See your gut microbiome (sum of the total microbes in the gut) as a beautiful internal garden. This beautiful colourful garden composes of trillions of different species of flowers (microbes) that orchestrate your health. In order for your internal garden to be diverse, beautiful and strong, it requires food. Therefore, just like the flowers in your home garden need water, sun and possibly a little fertiliser to grow, so does your internal garden. This food/fertiliser is known as prebiotics, whereas the good bacteria are known as probiotics.


Prebiotics are a fairly new term that was first introduced by Glenn Gibson and Marcel Roberfroid in 1995.  They are classed as are non-digestible carbohydrates that act as food for the trillions of microbes in your gut. They serve an incredibly important purpose. Oligosaccharides form the foundation for prebiotics. This consist of Fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), pectic-oligosaccharide (POS) and more.




How to get prebiotics? 

There are thousands of plants providing non-digestible fibres. Choosing the right foods will undoubtedly support the diversity of your gut microbes and therefore your immune function. Here is a list of some of the best prebiotic food sources:

  • Raw Leeks
  • Onions
  • Raw Garlic
  • Jerusalem artichokes
  • Asparagus
  • Sugar Beet
  • Chicory
  • Banana
  • Oats
  • Berries
  • Wheat
  • Honey
  • Cow’s milk
  • Beans
  • Seaweed & Microalgae

Nevertheless, it is believed that a diet rich in prebiotics might not be enough for some. As a result, FOS and GOS are being added to foods. Consequently, this in itself, may well be quite problematic for some.

Let me explain.

Years of living on a typical western diet, whatever you want to call it, is leading to a garden devoid of diversity and colour. This garden might present as overgrown with little diversity, lots of weeds and definitely some pests. When this happens, a clinical picture of ‘dysbiosis’ unfolds.

Dysbiosis, is when the balance of bacteria is distorted, and it may present as:

  • Bloating
  • Gas
  • Indigestion
  • Constipation/Diarrhoea
  • Pain
  • Flatulence
  • Belching
  • Heartburn
  • IBS
  • Or worse Chron’s/Ulcerative Colitis (further down the line)

Prebiotics vs Probiotics

Why can prebiotics worsen dysbiosis?

The primary function of prebiotics is to provide fuel for your microbes (good or bad). Prebiotics can therefore feed the bad bacteria, which can lead to overgrowth and potentially Small Intestinal Bacterial Overgrowth (SIBO).

This is often very frustrating for people trying to improve their gut health. I am seeing people who are using prebiotics, including prebiotic foods in the hope that they will improve their digestive symptoms, only to find that it makes it so much worse. This is NOT the case for everyone.

What is the answer?

There is no one right answer that will suit everyone. Everyone’s gut is individual. Having said this, people with digestive imbalance/dysbiosis, will be better off first addressing the imbalance in their gut before considering high levels of prebiotic foods or supplements. Once the imbalance is restored, there should be no reason why these foods and/or supplements couldn’t be introduced. I very much believe that it is all about timing and that everyone can eventually benefit from prebiotics.

In this post, I discuss how the 5R protocol can be used to restore gut health. This method has been tried and tested with over millions of clients. I personally have used it with over a hundred clients and know that it works if done right.

IBS and prebiotics

My advice to anyone with IBS is review the impact of small amounts of prebiotics on symptoms. If it worsens symptoms, then I highly recommend that you work with a qualified practitioner to address the underlying cause of your IBS. If prebiotic foods trigger symptoms, then is best to check labels for foods containing FOS, GOS, or any other oligosaccharide. The important thing to add is that excluding these foods in the long term is far from ideal. Ultimately, long term exclusion can have a significant impact of your beneficial bacteria. People with IBS already appear to have lower levels of beneficial bacteria and long term exclusion of prebiotics will only worsen this.

Prebiotic supplements

For those healthy individuals wanting to optimise gut health and supplement with some additional prebiotics, here are my all-time favourites.

  1. MegaPreBiotic by Microbiome Lab
  2. BioCare BioAcidophilus Forte (which contains both pre- and probiotics in)
  3. Biotics Research BioDoph 7 Plus (again combined pre- and probiotics)
  4. Biotics Research BioDophilus FOS


In conclusion. Firstly, if you are healthy with no digestive issues, then ensure to include as many prebiotic foods into your diet on a daily basis. Secondly, if you are presenting with digestive symptoms and seem to react to prebiotic foods (garlic and onions are the main culprits), then it might be wise to work with a qualified practitioner to address the underlying issues.

Happy Wellness Wednesday all.


Nutritional Therapist Cheshire, Health, Nutritionist Cheshire, Functional Medicine Cheshire, Rootcause Solution