Think of your gut as a garden. Probiotics are like seeds or new plants added to the soil, and prebiotics are more like the compost that nourishes particular plants already growing there. The comparison is not perfect, but it explains why two words that differ by only a couple of letters refer to quite different things.
Probiotics in brief
Probiotics are live microorganisms that provide a health benefit when consumed in adequate amounts. To earn the name, a specific strain needs supporting evidence. The US National Center for Complementary and Integrative Health notes that effects vary by strain, so a benefit shown for one strain does not transfer to another. Live-culture yoghurt and kefir contain bacteria, although not every fermented food meets the strict definition of a probiotic.
Prebiotics in brief
An expert panel of the International Scientific Association for Probiotics and Prebiotics, writing in Nature Reviews Gastroenterology and Hepatology in 2017, defined a prebiotic as a substance that microorganisms in the host use selectively, with a resulting health benefit. The panel kept two requirements at the centre: the effect must work through the microbes, and the health benefit must be documented. Most prebiotics in food are types of fibre, such as inulin, fructo-oligosaccharides and galacto-oligosaccharides. You do not digest them yourself. They travel to the large intestine, where bacteria ferment them.
The prebiotics you meet in food are essentially fibre-like, but not every kind of fibre counts as a prebiotic under that definition.
The difference at a glance
- Probiotics are living organisms, and prebiotics are not
- Probiotics are sensitive to heat and storage, while prebiotics are generally more stable
- Probiotic effects are tied to strain, while prebiotics feed the microbes already present
- Both have research behind them, and in both cases NCCIH describes the evidence for general wellness in healthy people as unsettled
Where to find prebiotics on a Jordanian table
You may already be eating them. Good sources include:
- Onions, garlic and leeks in everyday cooking
- Lentils, chickpeas and fava beans, so mujaddara, hummus and ful all count
- Oats and barley
- Slightly green bananas and asparagus
Whole grains such as freekeh add useful fibre to the plate too, and variety is the point. The NHS advises adults to aim for about 30 grams of fibre a day, and notes that most adults get only around 20 grams. It links a higher-fibre diet with a lower risk of heart disease, stroke, type 2 diabetes and bowel cancer, and with better digestion. Its suggestions are simple: wholegrain bread and cereals, potatoes with their skins, beans and lentils in meals, plenty of vegetables and fruit, and nuts or seeds as snacks.
Add fibre gradually
Increasing fibre quickly often brings gas and bloating. Add one extra portion every few days and drink more water as you go. People with irritable bowel syndrome may find that some prebiotic foods make symptoms worse, so a doctor or dietitian can help tailor the approach.
See a doctor if you have ongoing changes in bowel habits, pain, blood in your stool or unexplained weight loss. If you are pregnant, have a weak immune system or a chronic condition, or take regular medication, check with a doctor or pharmacist before using supplements. Some fibre products can affect the absorption of medicines, so ask about timing. Food remains the foundation here. Any supplement comes second.
Sources
- The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics · Nature Reviews Gastroenterology & Hepatology
- Probiotics: Usefulness and Safety · National Center for Complementary and Integrative Health (NCCIH), NIH
- How to get more fibre into your diet · NHS
This article is general health information for educational purposes and is not medical advice. It does not promote any product. Talk to your doctor or pharmacist before starting a supplement, especially if you are pregnant, breastfeeding, have a health condition or take medication.