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For Expert nutritional advice Contact Alan Gordon MSc. Clinical Nutrition
For Expert nutritional advice Contact Alan Gordon MSc. Clinical Nutrition
A flat lay of prebiotic, probiotic, and postbiotic foods including garlic, oats, yoghurt, kefir, and kimchi.

Prebiotics vs Probiotics vs Postbiotics

Gut health can feel complicated. With terms like prebiotics, probiotics, and the newer postbiotics, it is easy to feel lost. What do they all do? And do you really need all of them? Let’s clear up the confusion with no-nonsense advice.
Your gut is home to trillions of microorganisms, a complex community known as your gut microbiome. A healthy, balanced microbiome is crucial for more than just digestion. It supports your immune system, influences your mood, and plays a role in your overall health. Think of it as an internal ecosystem that needs the right care to function well. The ‘biotics’—pre, pro, and post—are the three key pillars that support this ecosystem.

What are prebiotics?

Think of prebiotics as the fertiliser for your gut. They are specific types of dietary fibre, like inulin and fructo-oligosaccharides (FOS), that your body cannot digest. Instead, they travel to your large intestine intact, where they become a targeted food source for your friendly gut bacteria. As the bacteria feed on these fibres, they ferment them and produce beneficial compounds.
According to , a leading voice on digestive health, a prebiotic is a substrate that is selectively used by host microorganisms to confer a health benefit. This fermentation process helps nourish your existing good bacteria, encouraging beneficial strains like Bifidobacterium to grow and thrive. This, in turn, helps to crowd out less desirable microbes.
Common prebiotic food sources include:
Garlic
Onions
Leeks
Oats
Jerusalem artichokes
Asparagus
Chicory root
Slightly under-ripe bananas
Including a range of these foods in your diet is the best first step. If you struggle to get enough fibre, a supplement like , which contains a blend of natural fibres including psyllium husk and flaxseed, can help support your daily intake.

What are probiotics?

Probiotics are the good bacteria themselves. The as live bacteria and yeasts that are promoted as having various health benefits. They are thought to help restore the natural balance of bacteria in your gut when it has been disrupted by illness, medication, or a poor diet.
These live microorganisms can be found in fermented foods or taken as supplements. To be effective, they must survive the acidic journey through your stomach and provide a health benefit. The most common groups are Lactobacillus and Bifidobacterium. Their mechanisms are surprisingly direct. They can compete with harmful bacteria for space and resources, produce substances that inhibit pathogens, and help to strengthen the gut wall lining.
Common probiotic food sources include:
Live yoghurt
Kefir
Sauerkraut (unpasteurised)
Kimchi
Miso
Tempeh
The that fermented foods like these are a great way to introduce beneficial microbes into your diet. For those looking for a more concentrated or targeted dose, a multi-strain supplement like provides a high-strength combination of eight different live cultures to support gut balance.

What are postbiotics?

Postbiotics are the new player in gut health, but they are not actually new at all. They are the beneficial compounds produced when probiotics (the good bacteria) feed on prebiotics (the fibre). Think of them as the valuable ‘byproducts’ of the fermentation process that happens inside your gut.
These compounds include short-chain fatty acids (SCFAs) like butyrate, acetate, and propionate. Professor Simon Gaisford of are “very important in maintaining good gut health.” Butyrate, for example, is the primary energy source for the cells lining your colon, helping to keep your gut wall strong and intact. This is critical for preventing a ‘leaky gut,’ where toxins could otherwise pass into your bloodstream.
Postbiotics are non-living, which makes them more stable than live probiotics. They help support the gut barrier, regulate the immune system, and reduce inflammation. You get them naturally when you consume prebiotics and probiotics, but they are also present in fermented foods where the microbes have already been at work.

How to build your gut health stack

Supporting your gut does not need to be complicated. The relationship is simple and synergistic: prebiotics feed probiotics, which in turn produce postbiotics. A healthy gut has a good supply of all three.
1.Start with prebiotics. Your first and most important job is to feed the good bacteria you already have. Focus on adding more fibre-rich, plant-based foods to your diet. Aim for variety. A breakfast of porridge (oats) with sliced banana is a great start. A lunch salad with onions and a side of asparagus provides even more fuel.
2.Introduce probiotics. Next, add fermented foods to your routine to introduce new, beneficial bacteria. Start small. A tablespoon of live yoghurt with your breakfast or a small glass of kefir is an easy win. Adding a forkful of sauerkraut or kimchi to your evening meal adds diversity.
3.Let postbiotics happen. By consistently consuming a diet rich in prebiotics and probiotics, you are creating the perfect environment for your body to produce its own postbiotics. This is the most effective way to benefit from these powerful compounds.
For most people, a balanced diet rich in a variety of plant foods and some fermented options is enough. However, if you are looking for extra support, particularly for issues like bloating or after a course of antibiotics, supplements can be a useful and targeted tool. You can explore a range of options in our .
Taking care of your gut is one of the best things you can do for your overall health. Start with small, consistent changes, and your body will thank you for it.
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