Prebiotics vs. probiotics, what is the difference?...and why should I care?

Updated: Jul 6, 2018

Although they may sound similar, prebiotics and probiotics are very different things and play different roles in the digestive system (or gut).

The short is that prebiotics feed our gut bugs whereas probiotics are the new bugs being introduced to our guts. For more details, continue reading…

Prebiotics come in the form of prebiotic fibre (undigested plant fibres). Typically, foods that are high in fibre are also high in prebiotics. Chicory root, garlic, leeks, onion, wheat bran and banana have particularly high concentrations.

This prebiotic fibre remains undigested until it reaches our large intestine. The bacterial colonies here ferment the fibre to release energy and “feed” on this energy. In general, the more prebiotics or “food”, the probiotics have to eat, the more efficiently the bacteria work and happier your gut will be.

Probiotics come from supplements and some foods like yoghurt, and unpasteurised kombucha and sauerkraut. The definition of a probiotic is “live microorganisms (bacteria) that, when administered in adequate amounts, confer a health benefit on the host” [1]

So why do we even care about feeding the little critters in our guts?

Answer: our gut bugs owns us!

Its true! The composition of our microbiome is as unique to each individual as our finger prints are. In fact, we have about 10 times the bacterial cells in our gut than our whole human body. This means that there are more than 3 million microbial genes in our guts—approximately 150 times more genes than the human genome [2].

The type, amount and variety of prebiotic fibre we consume over our lifetime effects the composition of our gut micro-biota… and without it, the bacteria in our large intestine get very hungry!

So what can I do to feed my gut bugs?

Recent research results have suggested that a diverse plant-based diet including more than 30 different types of plants each week makes for a more bacterially diverse gut. Consuming more than 30 types of plants per week seemed to lowered antibiotic resistance. Researchers in the area currently don’t know which specific prebiotics will alter with bacterial types, however the “microbiome GPS” is beginning to emerge as more microbiome samples are collected. Each sample collected and studied is a step closer to unravelling the complex way the microbiome is associated with various health and disease states [3,4,5].

When it come to probiotics, there are well documented benefits in a diet full of probiotics. This may include supplement, food and/or drinks. This is particularly beneficial for people who have recently received antibiotic treatment and may be lacking in some of the beneficial gut bugs [6].

[1] Lorenzo M, Lucio C. FAO/WHO Guidelines on Probiotics: 10 Years later. Journal of Clinical Gastroenterology, 2012; 46: S1-S2. doi: 10.1097/MCG.0b013e318269fdd5

[2] Qui J, Li R, Raes J et al. A human gut microbial gene catalog established by metagenomic sequencing. Nature, 2010; 464 (7285): 59-65. Doi: 10.1038/nature08821

[3] Medical News Today. “Largest” microbiome study weighs in on our gut health. [Internet]. [2018 May 15]. Available from:

[4] American Gut. Gut, Skin & Mouth. [Internet]. [2018 June 27]. Available from:

[5] McMillian J. 8 Steps to better gut health. Cited 2018 June 27. Available from:

[6] Crowe T. How Gut Bacteria Control Your Weight. [Internet]. [2018 June 27]. Available from:



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