The best prebiotic and probiotic combination pairs named probiotic strains with a prebiotic fibre those bacteria can feed on, in a form you will take every day. Put the two together and you have a synbiotic.
Probiotics get most of the attention. But live bacteria need food to work with, and that food is prebiotic fibre. Below, you'll find what a synbiotic is, how the two parts work together, what to check on the label, and the everyday foods that give you both.
What is a synbiotic?
A synbiotic is a mix of live beneficial bacteria (probiotics) and the fibres or compounds those bacteria feed on (prebiotics). The word comes from "synergy". It is spelled with an n. "Symbiotic" is a different word, describing two organisms that live together.
In 2020, the International Scientific Association for Probiotics and Prebiotics (ISAPP) defined a synbiotic as "a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host" (Swanson et al., 2020).
The panel described two types:
- Complementary synbiotic: a probiotic plus a prebiotic, each of which meets its own criteria.
- Synergistic synbiotic: live bacteria plus a fibre chosen specifically for those bacteria to use.
| Probiotic | Prebiotic | Synbiotic | |
|---|---|---|---|
| What it is | Live beneficial bacteria | Fibre or compounds gut bacteria feed on | Both together |
| Food examples | Kefir, yoghurt with live cultures, sauerkraut | Garlic, onion, legumes, oats, kiwifruit | Yoghurt topped with kiwifruit and oats |
How probiotics and prebiotics work together
Probiotics add bacteria. Prebiotics feed bacteria. A synbiotic does both at once.
- Probiotics arrive. You take in live bacteria, from a fermented food or a supplement.
- Prebiotics are the fuel. Your body can't digest prebiotic fibres, so they reach the large bowel intact. There, gut bacteria ferment them.
- Fermentation makes new compounds. As bacteria break down the fibre, they produce short-chain fatty acids such as butyrate. Researchers are studying these for their role in the gut.
ISAPP adds one important point: a probiotic and a prebiotic don't automatically make a synbiotic just because they sit in the same tub. To meet its scientific definition, the combination itself should be studied, not just each part on its own (Swanson et al., 2020). Synbiotic research is still young, so it's worth checking what a brand says about its formula and why.
How to choose the best prebiotic and probiotic combination
The best combination for you is the one with a transparent label, a prebiotic your gut tolerates and a format you'll take daily. Check these six things.
| What to check | Why it matters | What to look for |
|---|---|---|
| Named strains | Research is strain-specific, so "probiotic blend" tells you little | Genus, species and strain code, e.g. Bacillus coagulans Unique IS-2 |
| CFU per serve | Shows how many live bacteria you get in each serve | A clear number per serve, ideally guaranteed to the end of shelf life |
| Prebiotic source | Different fibres feed different bacteria | The prebiotic named, not just "fibre blend" |
| FODMAP content | Common prebiotics such as inulin, FOS (both fructans) and GOS are FODMAPs (Monash FODMAP) | Certified low FODMAP if you're sensitive to FODMAPs |
| Storage and survival | Some strains need the fridge; spore-forming strains are hardier | Clear storage instructions; shelf-stable if you travel |
| A format you'll keep up | A supplement only helps if you take it consistently | A dose, flavour and format (powder or capsule) that suits your routine |
If you follow a low FODMAP diet, the prebiotic matters most. Chicory root inulin is one of the most common prebiotics in supplements, and it is a fructan.
Inulin, FOS and GOS: what's the difference? Inulin and FOS (fructo-oligosaccharides) are fructans, chains of fructose sugars, often taken from chicory root. GOS (galacto-oligosaccharides) are chains of galactose sugars, found naturally in legumes (Monash FODMAP). All three are prebiotics, and all three are FODMAPs. GOS added to supplements is usually made from lactose (milk sugar), so check the label if you're vegan.
Synbiotic foods list: easy pairings
You can build a synbiotic on your plate by pairing a fermented food that has live cultures with a prebiotic-rich plant food.
| Probiotic food | Prebiotic food | Try it as |
|---|---|---|
| Natural yoghurt with live cultures | Kiwifruit, rolled oats | A breakfast bowl, like our 5-Minute Gut Reset Yoghurt Bowl |
| Kefir | Slightly green banana, oats | A breakfast smoothie |
| Miso | Leek, garlic, spring onion | A warming miso soup |
| Unpasteurised sauerkraut | Lentils, red onion | A lentil salad |
| Kimchi | Asparagus, garlic | A vegetable stir-fry |
| Tempeh | Onion, garlic | A tempeh and greens bowl |
Two things to know:
- Not every fermented food has live cultures. Shelf-stable sauerkraut and many supermarket pickles are pasteurised or made with vinegar. Look for "live cultures" or a fridge-only product.
- Many prebiotic foods are high FODMAP. Garlic, onion and legumes are rich in fructans and GOS. If you're sensitive, lower FODMAP choices include kiwifruit and oats. Check serve sizes in the Monash FODMAP app.
Synbiotic foods or a supplement?
You don't have to choose. Food gives you variety, plus all the other nutrients that come with whole plants. A supplement gives you named strains and a set amount in every serve, which is easier to keep consistent on busy days.
| Foods | Supplement | |
|---|---|---|
| Strains | Vary by batch and brand, often not listed | Named on the label |
| Amount | Unknown, varies | Set CFU per serve |
| Extras | Fibre, vitamins, minerals, polyphenols | Depends on the formula |
| Convenience | Needs planning and prep | One drink or capsule |
Our Probiotic Plus Prebiotic
We created Probiotic Plus Prebiotic to put both parts in one daily drink. Each serve combines:
- 3 probiotic strains: Bacillus coagulans (Unique IS-2), Lactobacillus gasseri and Lactobacillus rhamnosus, at 7.5 billion CFU per serve
- Kiwifruit prebiotics: Actazin (green kiwifruit) and Livaux (gold kiwifruit)
- L-glutamine and L-taurine
It's certified low FODMAP by FODMAP Friendly, vegan, and has a kiwi-lime flavour. Mix 2 teaspoons (7g) into water, as directed on the label. Read more on why we created it, or see the Gut Health Bundle.
Want a plan to go with it? Get our free 5-day gut health cleanse plan.
Synbiotic FAQs
What is the best prebiotic and probiotic combination?
One with named probiotic strains, a clear CFU per serve, a named prebiotic your gut tolerates, and a format you'll take every day. If you're sensitive to FODMAPs, choose a certified low FODMAP formula.
What's the difference between a probiotic, a prebiotic and a synbiotic?
A probiotic is live beneficial bacteria. A prebiotic is the fibre gut bacteria feed on. A synbiotic combines the two.
Can you take prebiotics and probiotics at the same time?
Yes. That's what a synbiotic is. Follow the directions on the label.
What are examples of synbiotics?
In food: yoghurt with kiwifruit and oats, kefir with banana, or miso soup with leek. In supplements: a powder or capsule that combines named probiotic strains with a prebiotic fibre.
Are synbiotics low FODMAP?
Not always. Many use inulin, FOS or GOS, which are FODMAPs. Look for a product that is certified low FODMAP.
Is it synbiotic or symbiotic?
Synbiotic, with an n, means a probiotic and prebiotic combination. Symbiotic describes two organisms living together.
References
- Swanson KS et al. (2020). The ISAPP consensus statement on the definition and scope of synbiotics. Nature Reviews Gastroenterology & Hepatology 17(11): 687–701.
- Monash University FODMAP. What are the oligos (fructans and GOS)?
