If you’re looking to incorporate more prebiotic foods into your diet, we’ve got you covered with a list of top choices.
First, let’s talk briefly about the difference between probiotics and prebiotics. Probiotics are live microorganisms that support your health when you consume them.
Prebiotics are compounds that support your health when certain gut microorganisms ferment them.
Prebiotics include certain types of fibre, plant chemicals and human milk oligosaccharides, which are found in breast milk.
Think of prebiotics as fuel for the good bacteria in your gut. You can read more about probiotics and prebiotics here.
The simplest way to feed your gut with prebiotics is to eat plenty of whole plants. Plants contain many types of fibre, including prebiotic fibres, such as inulin, fructooligosaccharides (FOS) and galactooligosaccharides.
Although all plants contain fibre, certain ones contain especially high levels of prebiotic fibre.
Different species of gut bacteria prefer different types of prebiotic fibre, so it’s best to eat a wide variety of plants to give your gut microbiome a real feast.
In turn, your ‘good’ bacteria will produce beneficial compounds such as short-chain fatty acids, which support your general health.
Experts recommend that we consume 30 grams of fibre a day, but most of us in the United Kingdom only get around 20 g a day. Focusing on eating enough prebiotics will help you reach that target.
There’s no official recommendation about consuming a certain amount of prebiotics, but some research suggests that we aim for around 3–5 g a day to get the health benefits.
Before we dive into our list of sources of prebiotics, here’s something to keep in mind: foods rich in prebiotics can trigger irritable bowel syndrome (IBS) symptoms. If you have IBS, check with your doctor or dietitian before you change your diet.
Now, on to our list of prebiotic foods.
1. Garlic
Garlic is renowned for its health benefits – so much so that Medieval Europeans believed it could ward off vampires due to its powerful antibiotic properties.
Modern science has confirmed some of garlic’s other health-promoting properties, including its potential to lower blood pressure and slow the progression of coronary artery hardening.
Garlic contains the prebiotic fibres inulin, FOS and allicin, which scientists believe may stimulate the growth of several ‘good’ types of gut bacteria, such as Lactobacilli, Bifidobacteria and Bacteroides.
2. Onions
Like garlic, onions contain inulin and FOS.
A bit more about FOS – some studies have shown that this type of prebiotic fibre has an anti-inflammatory and antioxidant effect, which improves the gut immune system and benefits overall health. This is important because 70% of your immune system sits along your gut.
Overall, adding onions and garlic to a recipe boosts flavour and your health, so it’s a win-win situation.
3. Leeks
Leeks belong in the same category as onions and garlic (the Allium genus, in case you’re wondering). Leeks offer similar prebiotic benefits, containing both inulin and FOS.
This long, thin vegetable is surprisingly versatile. You can use it in recipes like this roasted Mediterranean veggie frittata or this vegetable and pearl barley soup.
4. Jerusalem artichokes
Confusingly, Jerusalem artichokes aren’t native to Jerusalem – and they’re not artichokes. However, they are a prebiotic-packed plant and have been studied for their antioxidant activity.
Adding Jerusalem artichokes to a dish brings a sweet, nutty flavour, and either a crunchy or creamy texture, depending on how long you cook them.
Like leeks, they’re a versatile ingredient in many recipes.
5. Dandelion greens
Dandelion greens are the leaves of the dandelion plant. Though it’s often discarded as a weed, its leaves are highly nutritious.
Dandelion greens contain inulin, but they’re also rich in vitamins A, C, E, K and B, as well as a range of minerals.
Plus, these leaves contain flavonoids, which are a type of polyphenol.
Polyphenols are prebiotics that help support your gut microbiome. In fact, 90–95% of polyphenols are not absorbed and reach your gut microbiome ready for fermentation.
Taste-wise, dandelion greens have quite a bitter kick, so they’re not for everyone. But you can eat them raw or cooked, so they’re well worth a try.
6. Apples
A stranger to no one, the humble apple is a nutritional stronghold. It boasts a range of vitamins and minerals, as well as a healthy dose of fibre.
In fact, apples contain a range of fibres, including pectin.
Pectin is a soluble, viscous fibre that forms a gel in the gut. It's also a fermentable fibre that feeds gut microbes.
7. Oats
Oats are another humble ingredient and a great source of fibre. In particular, they contain high levels of a fibre called beta-glucans.
Studies suggest that beta-glucans may help lower cholesterol levels, thereby reducing the risk of cardiovascular disease.
This fibre may also improve your blood sugar responses after you eat. This is because, like pectin, it forms a gel in your gut.
Beta-glucans is also fermented by gut microbes and has prebiotic-like qualities.
So, maybe it’s time to try a new oatmeal recipe.
8. Barley
Like oats, barley is rich in beta-glucans, and it’s also a good source of vitamins and minerals.
Barley is usually ‘hulled’, which means that the grain’s tough outer coating (the hull) is removed during processing.
You might also find ‘pearled’ barley, in which case the hull and the kernel's outer coating are removed.
Both forms are still healthy, and both contain beta-glucans. Overall, hulled barley has slightly more total fibre than pearled barley.
With a slightly nutty taste and pleasantly chewy texture, barley works well in a range of dishes, including stews and soups.
9. Bananas
Worldwide, bananas are one of the most commonly consumed fruits.
Alongside inulin, bananas contain resistant starch, another fermentable fibre with prebiotic qualities which your digestive system can’t break down.
This means that the starch travels to your colon, where it feeds your gut microbes.
Resistant starch is good for your gut and overall health.
Both green and yellow bananas are healthy choices, but the greener they are, the more resistant starch they contain. As bananas ripen, their resistant starch is converted to simple sugars, such as fructose and glucose.
10. Avocados
Avocados are rich in healthy fats and prebiotic fibre, including pectin.
They also contain bioactive compounds, like phytosterols, which may support heart health.
If you’re looking for inspiration, why not make a quick, simple guacamole salad?
11. Asparagus
Asparagus contains inulin, which feeds your ‘good’ gut bacteria. It also contains xylose, a sugar that can have prebiotic effects.
Asparagus goes with all manner of savoury dishes, but it pairs particularly well with eggs and salmon.
12. Cocoa powder
Cocoa powder is made from fermented cocoa beans, which are rich in fibre. They also contain polyphenols with prebiotic powers.
Try sprinkling it in coffee, which also contains prebiotic fibre. Or, you might try cocoa powder on yoghurt, porridge or any other dish that needs a sweet pick-me-up.
13. Flaxseeds
Like many other plants, flaxseeds (or linseeds) are rich in fibre, including prebiotic types. A 100-g serving packs in about 26 g of fibre.
But unlike some other plants, flaxseeds are low in FODMAPs, making them suitable for people with IBS.
There’s also evidence that flaxseeds might ease constipation, reduce blood pressure and improve levels of fat in your blood.
Sprinkle them on salads or yoghurt, or add them to soups or smoothies.
14. Hazelnuts
Hazelnuts contain plenty of fibre and other healthy bioactive compounds.
They’re also rich in monounsaturated fatty acids (MUFAs), which are sometimes called ‘good’ fats. These can help reduce your levels of ‘bad’ cholesterol.
Most nuts and seeds contain MUFAs, but hazelnuts have particularly high levels.
15. Almonds
Like other nuts, almonds are a great source of prebiotic fibre, healthy fats, vitamins and minerals.
But compared with some other nuts, almonds have high levels of vitamin E.
They can be enjoyed on their own as a snack, but try to avoid products with lots of additives, sweeteners or salt.
16. Walnuts
Walnuts are another fibre-dense nutritional powerhouse, and when it comes to flavonoids and tannins, walnuts excel.
Flavonoids and tannins are polyphenols, so they have prebiotic activity.
17. Cashews
Like the nuts above, cashews contain a solid quota of healthy, bioactive plant compounds, as well as minerals and vitamins. They’re also rich in healthy fats and prebiotic fibre.
Try roasting cashews with some herbs or spices to get an extra dose of polyphenols.
18. Wheat bran
Wheat bran is the tough outer layer of the wheat kernel, and it’s packed with nutrients. It’s also low in calories and rich in prebiotic fibre.
Wheat bran contains a fibre called arabinoxylans, and studies show that adding even a small amount of wheat bran to your diet can improve your gut microbiome.
19. Mushrooms
Mushrooms, the first non-plant on our list, are highly nutritious fungi.
They contain several fibres with prebiotic potential, including chitin, hemicellulose, mannans and galactans.
In the past few years, mushrooms have been experiencing somewhat of a renaissance, and for good reason. They contain antioxidants, and there’s some evidence that they might reduce cancer risk and protect against viral infections.
For some fresh inspiration, try this crispy tofu, ginger and oyster mushroom stir-fry or these spiced mushroom pittas.
20. Fermented foods
Fermented fruit or vegetables – like those in kimchi, sauerkraut and miso – contain a range of fibres, including prebiotic fibres.
Because these dishes can contain prebiotics and live or inactive microbes, they can be synbiotics.
Overall, fermented foods can help support your gut microbiome, so try adding a portion per day into your routine.
21. Soybeans
Soybeans contain a good amount of prebiotic fibre, including oligosaccharides called raffinose and stachyose.
These beans are highly versatile and end up in a wide range of products. But it’s worth noting that soy milk has much less fibre than the whole bean, and soybean oil has none.
What are signs that you need prebiotics?
There are no specific signs that you need to eat more prebiotics. However, ensuring that your gut microbes are well fed is important for a stable, resilient gut microbiome.
As we mention above, it’s good to aim for 3–5 g of prebiotics a day, and this is achievable when you eat a wide range of plant-based foods.
The following could mean that you need to up your intake of fibre (including prebiotics):
- irregular bowel movements, like constipation or diarrhoea
- gut symptoms, including pain, bloating or gas
- piles or haemorrhoids
- feeling hungry after eating
Hunger right after a meal can indicate that you’re not getting enough fibre because fibre plays a key role in appetite.
If you’re planning to increase your intake of fibre, including prebiotics, take it slowly at first to give your gut time to adjust.
Summary
Prebiotics are fuel for your gut bacteria. They come in different forms, including fibre and polyphenols.
Most plants, including nuts, seeds, legumes, vegetables, fruits and whole grains contain healthy portions of prebiotics.
Some signs that you may need more fibre, including prebiotics, include changes to your bowel habits and digestive discomfort.
To learn more about gut health and other topics, visit Symprove’s Gut Hub.
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