The difference between probiotics and prebiotics explained
The topic of gut health has become more mainstream in recent years, with words such as prebiotic and probiotic being thrown around, but many of us are still confused about what these terms actually mean. So what is the difference between probiotics and prebiotics?
If you are one of these people, then don’t worry, I’m about to explain the difference between probiotics and prebiotics.
Let’s talk probiotics
These are live microorganisms, such as bacteria and yeast, that can have a positive effect on our health when consumed in the correct amounts.
Why are good gut bacteria important?
Well, they have many different functions in the body that you may never think of. For example, they help to develop the immune system, keep our digestive tract healthy, and reduce inflammation.
We know that probiotics are beneficial, but where can we actually get them from?
Good news for us! Probiotics can be found in common foods such as yoghurt containing ‘live cultures’, usually lactobacillus or bifidobacteria, and in other fermented foods such as kefir (fermented milk) and sauerkraut (fermented cabbage). As these foods contain live bacteria, they may have a positive role in gut health. Although it is hard to say how much of the bacteria actually makes it to the gut alive.
As well as the food sources I’ve just mentioned, probiotics are also available in capsule form. However, make sure that any probiotic supplements you buy are backed by good research. Unfortunately, not all probiotics are the same.
Let’s talk prebiotics
The scientific definition of a prebiotic is “a substrate that is selectively utilised by host microorganisms conferring a health benefit.”
What? In a nutshell, prebiotics are food for your good gut bacteria. We humans don’t have the digestive enzymes needed to break down prebiotic fibre. So, because of this, prebiotics make it all the way down to the large intestine, where trillions of bacteria and other microorganisms live. Amongst these trillions of bacteria in your gut, some like to ‘eat’ these prebiotic fibres, which helps the population of good bacteria to grow.
Why does this matter?
Well, we know that having a diverse range of bacteria in the gut is a good thing. Just like having a large population of beneficial bacteria helps to keep the bad bacteria in check.
So, where can we get prebiotics from?
Prebiotics can be found in many different plant foods such as fruit, vegetables, cereals, nuts, seeds and legumes. Some of the most studied prebiotics are fructooligosaccharides (FOS) and galactooligosaccharides (GOS), are in lentils, chickpeas, wheat, bananas, and leeks.
Prebiotic supplements are also available, and can be added to food and drinks. More recently, other compounds such as polyphenols and polyunsaturated fatty acids have been studied for their prebiotic potential. So prebiotics don’t necessarily have to be a type of carbohydrate.
Side note, if you have Irritable Bowel Syndrome (IBS), you may find that many prebiotic foods such as onion and garlic cause unpleasant symptoms.
This is because many prebiotics are also FODMAPs (Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols), which are a type of carbohydrate that good gut bacteria like. Fermentation of FODMAPs can lead to gas production and movement of water into the gut. This can lead to symptoms in some people. Speak with your dietitian for individualised advice on this.
What’s the best way to improve your gut health?
As everyone’s microbiota (a collective term for bacteria, yeast, fungi and viruses) is as unique as their fingerprint, there is no one size fits all!
We do know that one of the most important factors for maintaining a healthy and diverse population of gut microbes is the variety of plant foods in the diet, so this is a good place to start.
If you’re keen to optimise your gut health, try eating more types of fruit, vegetables, wholegrains, nuts, seeds and legumes. The more variety, the better. Also, keep in mind that if you’re not used to eating a high-fibre diet, it’s recommended that you increase your intake slowly, while making sure to drink plenty of water alongside it.
Fermented foods can be included regularly too if you enjoy them. A probiotic supplement may also be beneficial in certain conditions such as IBS.
It’s easy to make fermented foods at home, so get experimenting.
Aoife McDonald is a registered dietian based in Cork with a special interest in gut health, IBS and public health and promotion. For more information visit her Instagram on @thedigestivehealthclinic, which mainly focuses on IBS and gut health