What are prebiotics? How can they help leaky gut? And what are the best nutrition sources? Well, we’re going to answer all these big questions in this ultimate guide to prebiotic fiber & leaky gut!
Last Updated: Nov 3, 2023
In this guide, you’ll discover…
I know what you’re thinking…
“Prebiotics…hang on a second, I’m confused. I know about probiotics. They are the good bacteria in kombucha, sauerkraut and supplements, which help with food digestion, immune system, mood etc. But what the heck are prebiotics? And how can they help with leaky gut?!”
And I feel you. After all, it’s hard enough to wrap our heads around probiotics, let alone get to grips with this new term ‘prebiotics’.
But here’s the thing…
…whilst probiotics have been the most talked about thing over the last 10 years (almost like the Kardashians of gut health!), their best buddy in the world – prebiotics – may be even MORE important!
Especially, when it comes to helping us maintain a strong gut barrier – ie stopping leaky gut1.
The research that is being conducted in this area of health is so cutting edge and exciting. And that’s why I have spent the last 4 months diving into it all like some sorta GI-crazed Dr House.
But of course, I don’t want to overwhelm or bore you with all the complicated science. So in this guide we’re going to focus on just the most important ideas. And we’ll do it nice and slowly – and of course keep it all in plain English.
Prebiotics vs probiotics – what’s the real difference?
Simply put, prebiotics are food that your good bacteria (probiotics) can eat.
In other words, they are fuel for the good bacteria that live inside your gut and help them to grow strong – kinda like spinach for Popeye!
Prebiotics are found in many fiber-rich foods like green bananas, garlic, onion, jerusalem artichoke etc.
Which is why many people use the term ‘prebiotic fiber’ to describe them.
Okay, so as we all know, leaky gut occurs when our intestinal lining (which is the barrier between our gut and our bloodstream) becomes too permeable/leaky.
i.e. just like a bad strainer, it lets things move through the gut wall and into our bloodstream that it shouldn’t – eg large undigested food particles, bad bacteria or other microorganisms, toxins etc.
Now, with that in mind, you might be really scratching your head and wondering:
“How can eating more prebiotic fiber possibly reduce the leakiness of your gut wall?”.
Well, the easiest way to understand this is through an analogy
So inside your gut, like right now, there is a huge party going on. There are literally probably 50-100 trillion party goers in fact2.
I am of course talking about all the bacteria, yeast and other microbial party goers – both good and bad – that reside in your gut.
Together this collection of party people is known as your gut’s microbiome. And they largely reside in your large intestine (aka colon).
Now, just like with any party, if you invite good guests and keep them well fed with the food they love, they will be amazing guests. They will have fun, not be too loud, and probably even help you clean up.
By contrast, if you invite a bad crowd, don’t feed your guests – and end up being a bad host – then things can turn.
And, before you know it, starving guests will be rampaging through your cupboards, fridge and diving into the drinks cabinet…without permission.
Now your party is a catastrophe!
So without food (prebiotics) your good bacteria (probiotics) can end up Breaking Bad
It really is a series of unfortunate events that causes your colonic party-goers to ruin the vibe, make a mess, and leave you feeling worse for wear in the morning.
It starts off with the host inviting the wrong crowd. These are like the less helpful bacteria that also reside in your gut.
Of course, you might think that these invited guests that show up aren’t as bad as their reputations, but it becomes quite clear that they really are a nuisance when they arrive at the door. Even though you have some trusted friends at the party, these hooligans steal the show.
The same happens in your gut; these less helpful bacteria don’t seem so bad at first, but then they dominate the beneficial bacteria, and overcrowd their good efforts.
Now, on top of that, if you leave your guests unfed, everyone is going to start to get aggravated.
Ever heard of the term hangry?
Well, when the hunger rage begins, it can turn even the best of guests a bit crazy.
So, imagine this, you’ve got a party going on with loads of guests – some more friendly than others – and now, everyone is hangry.
If you haven’t provided party snacks, what’s the solution? Eat what’s already in the house.
In this exact same way, your bacteria need to be fed to thrive and survive – and, if they aren’t, they become desperate and have to eat whatever’s available within the body.
In the case of a lack of prebiotic fiber, these bacteria look for an alternate carbohydrate source: the intestinal cell wall. Additionally, this alternate fuel causes your bacteria to stop producing the compounds that support gut functioning3,4,5. A double blow to the home that houses them!
Now, keep in mind, you’ve still got those unwanted guests making the good guys feel uncomfortable and spoiling the party mood. These guests are not only interested in rummaging through your pantry – they may also be interested in trashing the house for fun!
If your good guests aren’t well-fed, they have no energy to tell off and kick out the bad guests. They become powerless and exhausted and simply let the bad guys take over and do even more damage.
The same with our good bacteria, if we don’t nourish them with sufficient food – AKA, prebiotic fiber – bad bacteria have the chance to overgrow, take over and cause some serious damage to the gut6,7.
So how’s that party going?
As you can see, the domino effect of a lack of prebiotics can result in good bacteria chomping away at your intestinal wall making it progressively thinner8,9, while bad bacteria is able to overgrow and cause all sorts of issues7!
The end result can leave you with leaky gut, poor digestion, and ongoing symptoms10,4.
This is why prebiotics are so important!
Providing sufficient prebiotic fiber allows good bacteria to flourish and even control the acidity of the stomach to fight off bad bacteria, while also repairing any damage to the carbohydrate-rich intestinal wall, which now has the time and resources it needs to rebuild itself6,7.
The result?
More of the good guys, less of those party poopers and a happier overall digestive system!
As you can see, when it comes to gut health, prebiotics provide a win from all angles!
A lack of prebiotic fiber is now thought to be a major contributing factor of increased intestinal permeability (i.e. leaky gut)
Although there are many potential causes of leaky gut – eg gluten, sugar, casein etc – a diet devoid of prebiotic fiber is starting to emerge as a leading cause11.
And given just how much of an impact it can have on the main line of defense – ie the mucus barrier – it will likely become the #1 focus of leaky gut protocols this year.
I am most fascinated because it looks like a potential root cause. Meaning if we can fix this, then we don’t need to spend so much time trying to fix knock on effects – eg food intolerances.
Here’s a question for you: what three types of meals would you rank as being the most delicious, that you wouldn’t think twice about munching on right now?
Did you say a juicy burger, a cheesy pizza and maybe a fat slice of chocolate cake?
That, unfortunately, is exactly the problem.
You see, these foods that make up a great deal of what we call a Westernized dietary pattern, are commonly no good for us12.
As happy as they may make your tastebuds, they are very low in nutritional value; and they’re very low in the essential fiber you’re now getting to know as being a critical part of your health.
Even many natural foods which are high in protein and nutrients, such as as grilled chicken or fish, provide you with very little in terms of the food you need to feed those friendly gut microbes – AKA, fiber13.
Our diets are filled with refined, processed and fatty foods, and it’s for this reason that most people only get around 15g of fiber a day. That’s a far cry from the minimum recommendation to have between 25-30g of the good stuff14, which should include at least 5g of prebiotic fiber that goes straight to feeding our lovely microbes!
Increasing your intake of fiber is easier than you think. And it really is an essential part of health, with research showing without any hint of doubt, that meeting your daily fiber requirements can reduce the risk of multiple diseases15.
There are so many healthy and tasty foods to include in your current meals – steak dinner, here’s looking at you – so that you’ll be able to meet your fiber requirements16.
Every. Single. Day.
As a general rule, if you want to get the most prebiotic fiber out of the following foods17, they are best eaten raw or lightly cooked.
And that’s because preparatory methods such as cooking and juicing can break down and even fully remove the fiber from them.
1) Jerusalem artichoke
This is a funny looking root veg, but also one really powerful prebiotic food, as it is packed with inulin. Best way to add this to your diet is to thinly shave it and use it in salads or soups.
Another approach – and one that can be done with most of these prebiotic foods – is to simply blend it into a tasty dip, along with other flavorful ingredients.
2) Garlic
Obviously garlic is super easy to cook with, but if we want to maximize the prebiotics in it, we need to try and eat it raw! Vampires begone!!
Now, the easiest way to consume it like this would be in salad dressings (ie crush a clove of garlic into your dressing) or mix a crushed clove into some savory dips/spreads.
Just keep in mind, that a little raw garlic goes a long way!
3) Green (under ripe) banana / plantain
Admittedly, green bananas don’t taste amazing by themselves. And that’s because they have not become ripe and thus the sugar content in them is quite low.
But given they are packed with resistant starch – which has prebiotic properties – we need to think of smart ways to incorporate them into our diet.
My favorite way is really simple. I just add 1 green banana to my daily shake and blend! If you haven’t seen my shake before, you can see the recipe in my free ebook.
4) Potato
I often get asked from people: “Do potatoes really have much of a prebiotic effect?”.
And well, if you just cook them and eat straight away (like most people do), the answer is not really. You see, potatoes really need to be cooked, then cooled, and then eaten, in order to deliver you big servings of resistant starch.
For example, in the form of a potato salad.
5) Fermented jicama and asparagus
Jicama is an underrated root vegetable that looks similar to a small turnip on the outside, while being completely white on the inside.
As for asparagus – most people are pretty familiar with its long green stem and spikey spears.
Raw asparagus & jicama are filled with beneficial prebiotics, but can be a bit hard to eat. So, try fermenting in spices (or lightly steaming) to make them edible.
Additionally, if you’d like to experiment with raw asparagus, look for young asparagus at the grocery store. You’ll know you’ve found them when the lower part of the stalk is still bright and green. The spears will be very soft, which makes them great for chopping and adding to salads.
6) Psyllium husk
Psyllium husk is a soluble fiber typically used to help with constipation as it draws water into the intestines, which helps to add bulk to stools. It does have a small prebiotic effect in that the gut bacteria ferment it more slowly than typical ‘stronger’ prebiotic fibers18.
One bonus is that it is often a cheaper source of prebiotics, and can be easily added to shakes, juices, soups and stews.
Warning: be sure to consume a lot of liquid when you’re using psyllium – otherwise, it can make constipation worse!
7) Raw chicory root powder
Chicory is very high in the prebiotic inulin. In fact, around 47% of its fiber is inulin-based19. Be wary, this ultra-high fiber content can make digestion a bit rough for sensitive tummies20.
It’s often used as a coffee substitute because of its rich, coffee-like flavour, which makes this prebiotic fiber an easy addition to your daily routine if you’re a coffee-lover.
Simply mix 2 teaspoons of the powder into your favourite shake or even into a serving of plain kefir or yogurt to boost the flavour and health benefits.
Adding it to yogurt can provide a double punch for your gut health; not only are you loading up on probiotics from the yogurt, but also prebiotics from the chicory root19.
8) Raw or cooked onions (or raw leeks)
Onions, which includes shallots and spring onions, are a great source of inulin prebiotic21. You may want to enjoy them raw in your salads, but they are also a fantastic option when they’re cooked and added to meals.
Leeks are another vegetable with a very distinct flavour. Their texture is a little tough when eaten raw, which makes cooked leeks the more popular option, although it’s not necessarily as fiber-rich as the raw form.
The bottom line is, your gut bacteria will probably enjoy that raw leek and onion salad a lot more than you will.
9) Avocado
Finally, a food that most of us can get down with!
Unlike the love-or-hate raw onion vibe, avocado has a much milder flavour and won’t send people running for the hills after they smell your post-meal breath.
Avocados are high in gut-friendly fibers and research has shown them to have beneficial effects on gut bacteria while also reducing inflammation22.
Slice them, smash them, turn them into a bowl of guac – there’s plenty of ways you can enjoy raw avocado and it’s benefits!
10) Dandelion greens
Dandelion greens are earthy, bitter, leafy greens which contain high levels of prebiotics23. They’re easy to toss into salads, but some people might be off-put by the bitter taste.
Try tossing this health-boosting plant into a bowl of mixed greens, so the bitter flavour doesn’t overpower your taste buds!
Now…
…before you go making a huge prebiotic salad with every ingredient on this list, you should first be aware of the potential issues with over-consuming most popular prebiotic foods.
Let me explain…
One of the things you need to be aware of when you begin increasing your intake of prebiotic fibers, is that they may have a tendency to cause a little digestive discomfort. O.K., in some people, it can be a lot of digestive discomfort.
Don’t let the thought of fibers fermenting in your colon, causing bloating, gas and maybe some diarrhea put you off, though! Your digestive tract is smart…it takes what you give it and works with it.
If you do have a sensitivity to prebiotics, start off slowly and then add more and more of the foods listed above every couple of days.
Often, the digestive system simply needs to get used to digesting the cell walls of the foods you’re eating; then, the healthy bacteria you do have, can start to use the prebiotic fibers to flourish and grow their army.
The more of these foods you eat, the bigger the army of good bacteria will grow, which will provide even more digestive ease as time goes on!
Pretty soon, you’ll be eating tons of these foods without so much as a rumble.
Of course, it’s best to get your prebiotic fiber from whole foods.
Why? Because you get so much more than you bargained for when you do (a host of other nutrients and different types of fiber that add even more value to your health).
But, let’s face it – not all of us are chomping on raw garlic and jerusalem artichokes in our lunch box each day.
In this case, fiber supplements certainly have their place.
If you find that you come up short every day on consuming prebiotic foods, supplements can be a great help to ensure you give your friendly gut bacteria the food they need to stay fed and flourish.
Prebiotic supplements are made from the same types of prebiotic fiber that are extracted directly from foods – such as those listed above. So, they’re all natural and have simply isolated the good stuff for feeding our gut bacteria!
The most common prebiotic fiber supplements contain inulin (a longer chain fiber) and fructooligoaccharide (a shorter chain fiber)24.
But, you go into a fiber-frenzy and start tossing prebiotics down your throat, let’s get into 3 warnings for how NOT to use prebiotic supplements that every prebiotic-user should abide by.
And believe me, these are some of the biggest yet most common mistakes I see people make, which can wreak gut havoc!
Tip #1 – Don’t fall for convenience
One of the most important factors to consider when you’re thinking about taking prebiotic supplements is that it should supplement the diet, and not replace the fiber you get from whole foods.
It’s easy to want to pop a pill and smash pizza and chocolate on the daily – but, that’s not how it works. Prebiotic supplements do not contain the full variety of fibers and nutrients you get from eating whole foods.
So, think of prebiotic supplements as your insurance policy – and a great one, at that! You’re ensuring your good bacteria gets the food it needs every single day.
Tip #2 – Go slow!
Don’t be this person:
“Prebiotic supplements? They’ll make my gut healthy? Great, I’ll take the whole bottle and then it will work really fast!”
It’s easy to get caught up in the more-is-better mentality. But, with prebiotics, that’s definitely NOT the case!
Unfortunately, this can backfire and cause some serious digestive discomfort such as bloating, pain, gas and more!
As discussed, your body needs time to adjust to higher levels of fiber and learn to digest it properly, as well as produce higher levels of the bacteria needed to process it25.
Go slow. Studies show doses starting at 2.5g/day of prebiotics can work well to begin providing bacterial benefits26, so beginning with this lower dose and increasing by an additional 2-3g weekly is a simple method for allowing your body to build increasing tolerance while getting the prebiotics it needs.
eg week 1 – 2.5g per day, week 2 – 5g per day, week 3 – 7.5g per day and then week 4 (and long term) sitting at 10g per day.
Tip #3 – Not all prebiotics are created equal.
Keep in mind that some types of fiber are easier on the digestive system than others.
For example, the commonly used prebiotic fiber, fructooligosaccharide has shown to have poor tolerance and cause symptoms even at low doses – while other fibers, such as acacia fiber have shown to be much gentler on the digestive system and provide greater benefits for gut health20.
Additionally, focusing on fibers that can survive the harsh digestive environment to get to where they’re needed are an important part of how effective they are27.
Choosing high quality, stable ingredients, as well as selecting fibers which are gentle on the digestive system are essential in order to maximize gut health benefits and avoid digestive distress.
Also, pay attention to capsules. Many capsule-based prebiotics have added fillers, colorants, and contain artificial ingredients which can rough up the gut as well, and end up doing more harm than good – especially for those with very sensitive tummies.
The best way to consume prebiotics is in a powder form, allowing you to adjust the dosage and go slow, as mentioned above, while ensuring you’re getting the fiber in its purest form – no additives, no fillers, just purely the good stuff!
So, how can you ensure you’re meeting all of these requirements?
From quality ingredients to supplement stability to digestive-friendly fibers – is there a supplement that ticks all these boxes at once?
With all of these considerations in mind, we wanted to create a prebiotic fiber supplement that ensured people could get their daily dose of prebiotics in a way that’s simple, convenient, and easy on the tummy.
That’s why we created this prebiotic.
It is a mix of two organic, non-GMO, plant-based prebiotics: acacia fiber and sunfiber.
Whilst most prebiotics use potentially gut irritating ingredients like chicory root, GOS or resistant starches, which can cause bloating, gas and even diarrhea20, these prebiotics uses fibers clinically proven to work gently.
In fact, research has found acacia fiber to produce greater increases in good bacteria with fewer gastrointestinal effects compared to the equivalent dosage of inulin20.
Our second amazing ingredient – Sunfiber – has shown to stay stable within the stomach environment and overall one of the most beneficial dietary fibers on the planet!27
This combination makes this prebiotic is a safe choice for a variety of digestive issues and those simply looking to keep their gut health tip-top!
Additionally, it comes in a powder form with a handy 2.5g scoop, instead of using capsules with set dosages, allowing you to go as slow or fast as you wish when adjusting the dosage!
Starting with just one 2.5g scoop daily is a great way to get your tummy used to digesting these prebiotics.
You can increase the dosage weekly by an additional scoop, or simply add half a scoop extra every 2-3 days.
By using fibers which are clean, gentle on the tummy, and have no artificial additives, you can improve your gut health and symptoms with ease and ensure you’re feeding your gut bacteria the food that it needs. Every. Single. Day.
So, if your digestion has been hungry for a change, feed your bacteria these prebiotics and start improving your gut health today!
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- Jalanka, J., et al. The Effect of Psyllium Husk on Intestinal Microbiota in Constipated Patients and Healthy Controls. Int J Mol Sci. 2019 Jan; 20(2): 433.
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