Pre, Pro & Postbiotics 101

“Trust your gut” is a phrase we often hear that encourages us to go along with our natural instinct. Every day we are tasked to make different decisions, and we hope that we make the right choices by listening to our gut instinct. But can we take this phrase literally? How much can we actually trust our gut? Will it naturally do the right thing, as the saying goes? Or do we need to guide it in the right direction in order to achieve balance? 

The microbes in your gut, commonly referred to as the microbiome, are extremely important to your overall health. Your gut is actually made up of different species of these microbes, and each one can be classified as being either “good” or “bad” for your health. These microbes play a vital role in not only digesting the food you eat but also in absorbing nutrients. About 30 to 50 trillion cells of bacteria make up the bulk of your microbiome. The human body itself contains about 37 trillion human cells, so actually, you’re roughly half bacteria and half human! The gut microbiome is hugely variable from person to person. Through research, it has been found that even identical twins have very different gut microbiomes, with unrelated individuals sharing 30% and twins sharing 34% of the same gut microbes

Everything you do to your body can affect your gut health. The food you eat, the topical products you apply, the exercise you undertake, even the amount of sleep you get – can 

positively or negatively impact the environment within your gut. The number of “good” bacteria within your gut’s microbiome can dictate how your body handles the aging process, digestion, immune system, protection against certain diseases, brain function and even your mood. This also means your skin is a direct reflection of your gut, or at least how healthy it is. You may have heard of prebiotics, probiotics and postbiotics, relating to foods and supplements that claim to boost the ‘good’ bacteria in your gut. Let’s break down the key differences between these three.

Prebiotics - Food For The Microbes

Prebiotics provide food for the bacteria (microbes) in your gut, and help to promote and encourage their growth. These bacteria microbes help our bodies to break down the many different types of fiber that we are otherwise unable to break down ourselves. When we eat, our gut is great at breaking down starch, which starts to degrade after we chew our food. Plant fibers, on the other hand, are not easily broken down by our gut microbiome. Fiber requires additional help to be broken down, and our microbe friends save the day by helping us to properly digest this. If you deplete your body of certain foods, certain strains of bacteria won’t be in your gut to help break down the fiber that your body needs. Providing your gut microbiome with the right food will result in the right microbe coming to eat it. Prebiotics can help to increase the number and the variety of microbes, which will result in a healthier gut microbiome overall. To be classified as a 'prebiotic,' the food molecule must selectively stimulate the growth or activity of microbes that are beneficial to our health. Most prebiotic molecules are plant fibers, so eating lots of plants is always a good start. As they are naturally occurring, you can find them in such foods as greens, bananas, whole grains, onions and garlic, or you can increase your intake of prebiotics through supplements. Essentially, they are a source of food for your gut’s healthy bacteria, and help to build a healthy digestive system overall!

Probiotics - The Microbes

Probiotics contain the live microbes that will (hopefully) populate our gut and give us health benefits. The World Health Organization defines "probiotics" as "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host." Essentially, the more strains of bacteria microbes that populate your microbiome, the better your gut is equipped to break down what your body isn’t able to. Fermented foods, including yogurt, kefir, kimchi, and sauerkraut contain live bacteria and act as probiotics. A healthy and diverse population of bacteria within your microbiome can help to aid digestion, boost the helpful chemicals that these microbes produce, prime the immune system, and also reduce the growth of “bad” bacteria microbes living in the gut. This natural bacteria is also essential for good skin health. 

Postbiotics - What Microbes Produce

After the bacteria microbes are done eating the indigestible fiber in your gut, they produce waste molecules called metabolites. These waste molecules, along with dead cells and parts of cells produced by your microbiome, are known as postbiotics. The benefits of taking postbiotics, or eating more postbiotic foods, include boosting your immune system, helping to reduce digestive symptoms and potentially helping and preventing future issues within the gut microbiome. Scientists have identified hundreds of postbiotic chemicals that are produced in the microbiome and play many different roles in protecting your health. They include:

  • Vitamins B and K that maintain cell health and help with blood clotting, respectively.
  • Short-chain fatty acids which help maintain your gut lining, act as signals to your body and brain, influence your metabolism, and have anti-inflammatory effects
  • Antimicrobial molecules that kill harmful microbes
  • Bacterial fragments and cells that can prime your immune system to help fight off infections.

Like we said before, the more strains of bacteria your gut microbiome has, the healthier it is. This means that a healthy, diverse microbiome that is well fed will naturally produce metabolites, so if you keep your microbiome robust and healthy, it will keep churning out these postbiotics! Whilst all of these can be found naturally in certain foods, taking more in the forms of supplements can benefit your gut (and overall) health.

We hope you enjoyed learning about pre, pro and postbiotics, and hopefully you understand the differences between them a little bit better now! If you have any questions at all you can always reach out to me at!



Nourished Academy. “Pre, Pro and Postbiotics – What's the difference?” Nourished, 29 July 2021, Accessed 17 December 2021.

Tyler, Caitlin, and Andrea Jones. “The importance of your microbiome.” Chuckling Goat, The Gut Health Experts, Accessed 17 December 2021.

ZOE. “What are prebiotics, probiotics, and postbiotics and how do they work?” ZOE, 1 October 2020, Accessed 17 December 2021.