54 Hope St, Brunswick VIC 3056
0406 154 886
Email Us
Probiotics vs prebiotics is a comparison that gets more confusing the more labels you read. Walk down the drinks aisle of any Australian supermarket and half the bottles claim probiotics. Half the rest claim prebiotics. Plenty claim both. Most people pick one up without being clear on the difference, and without knowing whether the claim on the label means anything at all.
At Good Brew, we’ve been making raw kombucha in Brunswick since 2007, and we get the ‘is it a probiotic?’ question constantly. The honest answer is more nuanced than either side of the argument usually admits. Here’s what probiotics and prebiotics are, what kombucha contains, and which one you might need.
Probiotics vs prebiotics at a glance
Both matter. They do different jobs, and most gut-health routines benefit from a bit of both.
| Type | What it is | Common food sources | What it does |
|---|---|---|---|
| Probiotics | Live bacteria and yeasts | Yoghurt with live cultures, kefir, sauerkraut, kimchi, raw kombucha, miso | Adds live microbes that may support your existing gut community |
| Prebiotics | Plant fibres your body can’t digest | Garlic, onion, leeks, asparagus, oats, legumes, slightly underripe bananas | Feeds the beneficial microbes already living in your gut |
Probiotics: what they are (and why ‘contains probiotics’ often means nothing)
Probiotics are live microorganisms that, when consumed in adequate amounts, confer a health benefit on the host. That’s the definition set by the International Scientific Association for Probiotics and Prebiotics (ISAPP), adopted by the World Health Organization and the Food and Agriculture Organization.
Three words in that definition do the heavy lifting: live, adequate, and specific.
- Live means the microbes have to survive to reach your gut. Pasteurisation, heat treatment, and long shelf-life processing all kill them.
- Adequate means there needs to be enough of them. Different strains are studied at different doses, but Australian consumer advocate CHOICE notes that you typically need at least 10 billion colony-forming units (CFU) for most probiotic strains to have a measurable effect.
- Specific means the strain matters, not just the species. Lactobacillus rhamnosus GG is a different probiotic from Lactobacillus acidophilus La-14, which is a different probiotic again from Bacillus coagulans. Research on one strain doesn’t apply to the others. A 2021 review published in the Journal of Alternative and Complementary Integrative Medicine analysed 510 probiotic products on the Australian Register of Therapeutic Goods and found that none of the public summaries listed their strains, despite strain being the variable that determines effect.
So when a drink label says ‘contains probiotics’ without naming the specific strain and disclosing the CFU count at the end of shelf life, the claim is mostly marketing. It might be true in the loose sense that there are live cultures in the bottle. It’s rarely enough to back up any specific health claim.
Prebiotics: the fibres that feed the microbes you already have
Prebiotics are a type of dietary fibre that your body can’t digest, but that beneficial gut bacteria can. Monash University’s Department of Gastroenterology defines a prebiotic as fibre that passes through the gut undigested and stimulates the growth or activity of certain ‘good’ bacteria in the large intestine.
In plain terms: prebiotics feed your existing gut community. You don’t need to add new microbes if the ones you already have are well fed.
Common prebiotic foods Australians can find easily include garlic, onion, leeks, asparagus, Jerusalem artichoke, legumes, oats, barley, rye, and slightly underripe bananas. Most fruits, vegetables, and wholegrains contain some prebiotic fibre.
The problem is intake. The National Health and Medical Research Council (NHMRC) sets the Adequate Intake for dietary fibre at 25g per day for adult women and 30g per day for adult men. According to Healthdirect and the Queensland Department of Health, most Australians don’t hit these targets. A person eating a typical Australian diet is more likely to be short on fibre than short on probiotics.
This is why, for a lot of people, prebiotic fibre does more measurable gut work than taking a probiotic supplement. You can measure what you eat. You can reliably increase it. The gut community already adapted to you gets fed, rather than asking a handful of foreign microbes to survive stomach acid and take up residence.
Does kombucha have probiotics? The honest answer
It depends on the kombucha.
Raw, unpasteurised kombucha contains live cultures. Acetic acid bacteria including Komagataeibacter, Gluconobacter, and Acetobacter species, plus a range of yeasts, and sometimes Lactobacillus. Most supermarket kombucha is pasteurised or heat-stabilised to extend shelf life, which kills most or all of them. If the label doesn’t explicitly say ‘raw’ or ‘live’, it has probably been heat-treated.
Here’s where we have to be straight with you: even raw kombucha doesn’t automatically meet the formal probiotic threshold.
The US Office of Dietary Supplements, part of the National Institutes of Health, notes that kombucha is a fermented food containing live cultures but does not typically contain proven probiotic microorganisms. A 2023 study published in the journal Beverages surveyed 39 commercial kombucha products and found that only 6.3% of non-alcoholic kombuchas exceeded one million CFU per millilitre, the benchmark most research uses for a probiotic-adequate dose. The median was well below that.
That doesn’t mean live-culture kombucha isn’t valuable. It means the word ‘probiotic’ sets a specific bar that most kombucha, including ours, doesn’t reliably clear. What raw kombucha does reliably deliver is worth being specific about.
Live microbial cultures. Below the formal probiotic threshold, but still contributing to fermentation-derived compounds that research is continuing to map.
Organic acids. Acetic acid and gluconic acid produced during fermentation, which contribute to kombucha’s tartness and its low pH.
Polyphenols. From the tea base. Research suggests green and black tea polyphenols may support antioxidant activity in the body.
A genuine lower-sugar alternative to soft drinks. Live-culture kombucha ferments down most of the brewing sugar. What’s left in the bottle is a fraction of what you’d find in a soft drink, without added sweeteners.
At our Brunswick brewery we use organic tea, Daylesford spring water, and local honey. We don’t pasteurise, and we don’t add isolated probiotic strains to hit a CFU marketing claim. What’s in the bottle is what the live culture produces, which is how kombucha has been made for centuries.
Calling that ‘probiotic’ without qualification would be overstating it. Calling it ‘live-culture fermented tea with real organic acids and polyphenols’ is accurate, and that’s what you’re drinking.
Which one do you need?
The answer depends on what you’re trying to do. A few common scenarios:
- After a course of antibiotics. Antibiotics wipe out gut bacteria indiscriminately. A targeted probiotic supplement with a specific strain studied for post-antibiotic recovery, such as Saccharomyces boulardii or Lactobacillus rhamnosus GG, is generally a better fit. Raw kombucha on its own isn’t strong enough for this job.
- General gut maintenance with no symptoms. Prebiotic fibre from varied whole foods usually does more than a supplement. Aim for the NHMRC fibre target, include fermented foods (raw kombucha, live-culture yoghurt, sauerkraut, kefir) a few times a week, and you’re giving both sides of the system what they need.
- Ongoing digestive irregularity. Start with a food diary and talk to a GP or Accredited Practising Dietitian. Irregular digestion can have many causes, and a supplement isn’t the first place to look.
- Suspected IBS or more significant symptoms. Don’t self-diagnose from the supplement aisle. Monash University’s low-FODMAP protocol is the evidence-based starting point, and it restricts some prebiotic foods in the short term. Work with a qualified dietitian before restricting your intake.
- You just want a drink that isn’t a soft drink. Raw kombucha is a reasonable everyday swap. You’re getting live cultures, organic acids, tea polyphenols, and a fraction of the sugar of a soft drink.
None of this is medical advice. If you have specific symptoms, talk to a GP or dietitian before changing anything significant.
Frequently asked questions
Is kombucha a probiotic?
Not in the formal regulatory sense. Kombucha contains live cultures when it’s raw and unpasteurised, but most samples don’t meet the strain-specific, CFU-count threshold that defines a probiotic product. It’s better understood as a live-culture fermented food with its own set of benefits.
Can I take a probiotic supplement and eat probiotic foods at the same time?
Yes, and for most healthy people it’s fine. Healthdirect advises that people who are immunocompromised or seriously unwell should check with their doctor before starting any probiotic regime.
How many CFUs does kombucha have?
It varies enormously. Published research shows CFU counts in commercial kombucha ranging from around 100 to ten million per millilitre, with most falling well below the one million threshold used for probiotic claims. The count depends on brewing method, tea base, fermentation time, storage, and whether the product has been pasteurised or had isolated strains added after fermentation.
Is kefir better than kombucha for probiotics?
Yes, if strict probiotic content is what you’re after. Milk kefir and water kefir generally have higher and more diverse live microbial counts than kombucha, and are more likely to meet probiotic-adequate doses. Kombucha’s strengths sit elsewhere: lower sugar, tea polyphenols, organic acids, and a flavour profile most people find easier to drink regularly than kefir.
Last word: match the tool to the job
Probiotics and prebiotics aren’t competing products. They’re two parts of how your gut works. If you already eat well and drink live-culture kombucha a few times a week, you’re likely doing more for your gut than the average supplement-buyer. If you have a specific medical reason to use a probiotic, a targeted supplement with named strains and studied doses will do more than any fermented drink.
This article is general information, not medical advice. For anything ongoing, talk to a GP or an Accredited Practising Dietitian.
If you want live-culture kombucha that’s raw, unpasteurised, organic, and honest about what it is, our range is brewed in Brunswick and delivered across Melbourne. We also run monthly workshops at the brewery if you want to see the fermentation in person and ask the questions this article couldn’t cover.