Prebiotics and Probiotics: Two Different Allies for Your Gut Health
🔬 What they are, how they work and why it is important not to confuse them
What do probiotics and prebiotics have in common?
Prebiotics and probiotics work together , but they are not the same thing.
👉 Probiotics are live microorganisms that provide health benefits to the host.
👉 Prebiotics are non-digestible fibers that selectively feed these beneficial microorganisms.
Both support the gut microbiota , but they do so in different ways. And knowing the distinction is essential to building a balanced diet, especially in an era in which gut health is considered central to the overall well-being of the organism.
🧫 What are probiotics?
Probiotics are defined by the World Health Organization as:
“Live microorganisms which, when administered in adequate quantities, confer a health benefit on the host.”
They are good bacteria, already present in the human intestine, which can be integrated through:
- Fermented foods (yogurt, kefir, sauerkraut, miso)
- Probiotic supplements with selected and vital strains
The most well-known strains:
- Lactobacillus
- Bifidobacterium
- Saccharomyces boulardii (a probiotic yeast)
☝ Probiotics must reach the intestine alive and in sufficient numbers to exert their effect. This is why formulation and storage are crucial.
🌱 What are prebiotics?
Prebiotics are indigestible substances , mostly fiber, that reach the colon intact, where they are fermented by the microbiota , selectively stimulating the growth of beneficial bacteria.
According to the updated ISAPP definition:
“A prebiotic is a substrate selectively utilized by host microorganisms that confers a health benefit.”
Not all types of fiber are prebiotics. Only a few substances have been scientifically proven to nourish specific “good” strains.
The most common:
- Inulin
- Fructooligosaccharides (FOS)
- Galactooligosaccharides (GOS)
- Resistant starch
- Beta-glucans
📊 Comparison table
| I wait | Probiotics | Prebiotics |
|---|---|---|
| What are they? | Live microorganisms | Non-digestible fibers |
| Function | Temporarily colonize the intestine | Feed the beneficial bacteria already present |
| Examples | Lactobacillus, Bifidobacterium | Inulin, FOS, GOS, resistant starch |
| Where are they located? | Yogurt, kefir, supplements, fermented | Vegetables, legumes, whole grains, supplements |
| Benefits | They regulate flora, support immunity | They promote the growth of beneficial microbiota |
| Risks | Rare, but to be evaluated in immunosuppressed patients | Initial swelling if taken in excess |
🧠 How do they work in the body?
✅ Probiotics:
- They colonize the intestine (temporarily)
- They produce acids and bacteriocins that fight pathogens
- They strengthen the intestinal barrier
- They modulate the immune response
✅ Prebiotics:
- They nourish probiotics (both ingested and endogenous)
- They promote the production of short-chain fatty acids (SCFA) such as butyrate, acetate and propionate
- They support the balance between beneficial and potentially harmful strains
- They act indirectly on metabolism, inflammation and mineral absorption
🧬 The perfect synergy: the concept of symbiotic
When a probiotic and a prebiotic are taken together to work synergistically, we are talking about:
Symbiont (or symbiotic) = Probiotic + Prebiotic in the same formulation
Example:
- Lactobacillus rhamnosus GG + Inulin
- Bifidobacterium lactis + FOS
These combinations optimize:
- The survival of the probiotic
- Intestinal colonization
- The effectiveness on the microbiota
⚠️ Do you need to be careful?
Yes, in some cases.
- Probiotics must be chosen carefully: each strain has specific effects, and not all are the same .
- Prebiotics , if taken too quickly or in excess, can cause:
-
- swelling
- gas
- accelerated transit
For this reason, it is advisable to start gradually , especially if you suffer from irritable bowel syndrome or are taking a supplement for the first time.
In the presence of intestinal pathologies, autoimmune conditions or chronic drug use, it is always advisable to consult your doctor or nutritionist before introducing probiotics or prebiotics in a targeted manner.
🧾 Practical examples: where can we find them?
Natural Probiotics:
- Yogurt with live cultures
- Kefir
- Fermented sauerkraut (unpasteurized)
- Miso, tempeh, kombucha
Prebiotic foods:
- Raw chicory
- Jerusalem artichoke
- Onion, leek, garlic
- Oats, rye
- Unripe banana
- Legumes
🔚 Conclusion: Two allies, one goal
Prebiotics and probiotics are not interchangeable , but complementary . Together they can support our gut, immune system, metabolic health and even emotional balance.
🧠 A healthy gut is much more than good digestion: it is a solid foundation for general well-being.
Knowing the difference between these two allies is the first step to eating better, with greater awareness… and with long-term benefits.