The probiotics and prebiotics are everywhere: in yoghurts, in supplements, in conversations about the gut. They sound alike, but they are not the same thing. In this guide you will see what each one is, which foods contain them, what research really shows, what officially applies in the European Union and 6 things worth knowing.
What probiotics are
According to the definition of the international scientific association ISAPP (2014), probiotics are live microorganisms that, when taken in adequate amounts, provide a health benefit. The best known belong to the genera Lactobacillus and Bifidobacterium, while the yeast Saccharomyces boulardii.
What matters is the strain: two strains of the same species can act differently. That is why the results of a study apply to the strain and dose tested, not to “all probiotics”.
What are prebiotics
Prebiotics are the “food” of the good bacteria. The ISAPP definition (2017) describes them as substances that are selectively used by the microorganisms in our body, providing a health benefit. The most studied are inulin, fructooligosaccharides (FOS) and galactooligosaccharides (GOS).
Most prebiotics are dietary fibres, but not all dietary fibres are prebiotics.
Probiotics and prebiotics at a glance
| Question | Answer |
|---|---|
| Probiotics | Live “good” bacteria or yeasts. |
| Prebiotics | Fibres that feed the good bacteria in the gut. |
| Where probiotics are found | Yoghurt and kefir with live cultures, some fermented vegetables, supplements. |
| Where prebiotics are found | Onion, garlic, leek, asparagus, artichoke, legumes, oats, banana. |
| Approved EU claim for “probiotics” | There is none. |
Which foods contain them
| Food | What it offers |
|---|---|
| Yoghurt, kefir | Live bacterial cultures. Choose plain ones, without added sugar. |
| Fermented vegetables | Naturally fermented pickles, sauerkraut, kimchi. Those that have been pasteurised or made with vinegar contain no live bacteria. |
| Onion, garlic, leek | Inulin and FOS. |
| Artichoke, asparagus | Inulin. |
| Pulses | GOS and dietary fibre. |
| Oats, barley | Beta-glucans and dietary fibre. |
| Slightly unripe banana, cold boiled potato or rice | Resistant starch, which is fermented in the large intestine. |
A Mediterranean diet with vegetables, legumes, fruit and wholegrains naturally provides prebiotic fibre. EFSA recommends for adults at least 25 g of dietary fibre a day, but most Europeans get less.
What the research shows
- Fermented foods: in a Stanford University study (2021, 36 healthy adults, 10 weeks), a diet rich in fermented foods increased the diversity of gut bacteria and lowered 19 markers of inflammation in the blood. The group that only increased fibre did not see the same changes in the same period. It is a small study, but it shows that food matters.
- Antibiotic-associated diarrhoea in children: the 2019 Cochrane review (33 studies, 6,352 children) found diarrhoea in 8% of children who took probiotics, compared with 19% without. The benefit was seen mainly at high doses (at least 5 billion CFU a day) and with specific strains, such as L. rhamnosus and S. boulardii.
- Other uses, such as bloating or irritable bowel syndrome: results vary greatly from strain to strain and the evidence does not allow general conclusions.
The conclusion: probiotics are not a “magic” solution for everyone. The foundation of a healthy microbiome is everyday diet.
What officially applies in the European Union
In the EU, a product may state that it “contributes” to something only if the claim has been authorised after assessment by EFSA (Regulation (EU) 432/2012). There is no authorised health claim for probiotics. That is why in many EU countries the word “probiotic” is not even allowed on the packaging, and products simply list the strains they contain.
There are two authorised claims related to the topic:
- The live cultures in yoghurt improve lactose digestion of the product in people who have difficulty digesting lactose.
- The chicory inulin contributes to normal bowel function by increasing stool frequency. This beneficial effect is obtained with a daily intake of 12 g of chicory inulin.
6 things worth knowing
| What to know | Why |
|---|---|
| 1. Diet first | Vegetables, legumes and fermented foods feed the microbiome every day. A supplement does not replace them. |
| 2. The strain matters | Check on the label which strains it contains, not just the word “probiotic”. |
| 3. So does the amount | The label states the CFU, i.e. how many live bacteria each dose contains. |
| 4. Increase fibre slowly | Prebiotics may cause gas or bloating at first. Increase them gradually and drink enough water. |
| 5. After antibiotics | Ask your doctor or pharmacist which strain to take and when, in relation to the antibiotic. |
| 6. Caution in vulnerable groups | In seriously ill or immunocompromised people, probiotics are given only on medical advice. |
Who should be careful
- People with a weakened immune system or a serious illness: only after discussing it with their doctor.
- Pregnancy and breastfeeding: ask your doctor before starting any supplement.
- People with severe gastrointestinal symptoms (pain, blood, weight loss): medical assessment first, not a supplement.
Probiotics and dietary fibre in Active Woman products
The Slim Probiotics contains 6 different strains of friendly bacteria (Bifidobacterium animalis, B. bifidum, B. longum, Lactobacillus acidophilus, L. casei rhamnosus, Streptococcus thermophilus), a total of 10.2 billion CFU per capsule, together with 100 mg of inulin. Like all probiotics in the EU, it has no authorised health claim.
For dietary fibre, the Xtra Fibre & Prebiotics and the My Fibre Plus are high in fibre. Sugar beet fibre contributes to an increase in faecal bulk.
Slim Probiotics and Xtra Fibre & Prebiotics are available together in the package Gut Health Support.
Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle.
Get to know your own microbiome
Read more about the gut microbiome and the 6 eating habits that support it, about glucomannan and to metabolism. If you want to see what is happening in your own gut, there is the gut microbiome analysis. For a personalised programme, you can book an online appointment or start with the Digital Diet.
Frequently asked questions
What is the difference between probiotics and prebiotics?
Probiotics are live good bacteria. Prebiotics are fibres that feed them, such as inulin.
Do I need a probiotic supplement?
Most healthy people are covered by a diet rich in vegetables, legumes and fermented foods. If you are considering a supplement, discuss it with your doctor or dietitian.
Do I take them with antibiotics?
In children, certain strains at a high dose reduced antibiotic-associated diarrhoea. Your doctor or pharmacist will tell you which strain and when to take it.
Is yoghurt enough?
Yoghurt with live cultures is a good choice, especially plain. Together with vegetables and legumes, it gives the gut both bacteria and their food.
Why do I get bloated with fibre?
Bacteria ferment the fibre and produce gas. Increase fibre gradually and drink enough water so that the gut gets used to it.
Are there side effects?
In healthy people, probiotics are generally well tolerated. Mild gas may occur at first. Immunocompromised or seriously ill people need medical advice.
Sources
- Hill C. et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol, 2014.
- Gibson GR. et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics. Nat Rev Gastroenterol Hepatol, 2017.
- Guo Q. et al. Probiotics for the prevention of pediatric antibiotic-associated diarrhea. Cochrane Database Syst Rev, 2019.
- Wastyk HC. et al. Gut-microbiota-targeted diets modulate human immune status. Cell, 2021.
- Regulation (EU) 432/2012 – List of authorised health claims.
- Regulation (EU) 2015/2314 – claim for chicory inulin.
- EFSA NDA Panel. Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fibre. EFSA Journal, 2010.
- ISAPP. «Probiotic» on food labels in Europe.
This article is for information purposes and is not a medical diagnosis, nor does it replace a doctor’s advice.
