You have probably heard of probiotics and prebiotics. Are they the same? Can a varied diet provide them, is supplementation needed, and why do they matter?
Our flora includes many bacterial species throughout the gastrointestinal tract, from mouth, pharynx, oesophagus and stomach through both intestines to rectum and anus.
The balance can be disrupted by antibiotics or poor diet, allowing unhelpful bacteria to proliferate, with poor digestion, nutrient absorption and immune function.
Here is how to support that balance.
What Are Probiotics?
Probiotics and prebiotics differ. Let us start with probiotics.
The term probiotics describes beneficial live microorganisms that support intestinal flora and health.
They can be consumed as probiotics in supplements or foods, including food-based products, supporting intestinal flora. Familiar beneficial bacteria include lactobacilli and bifidobacteria.
No clear consensus establishes the optimal dose. Studied doses range from 10⁸ to 10¹¹ colony-forming units daily.
What Are Prebiotics?
By contrast, prebiotics are not microorganisms but compounds supporting intestinal flora.
They are prebiotics because they provide food for beneficial bacteria, encouraging selective growth.
The category prebiotics includes soluble fibres in whole grains, pulses, fruit and vegetables.
Functions of Probiotics and Prebiotics
Having distinguished probiotics and prebiotics, here are their functions.
Possible probiotic functions include:
- Binding harmful molecules.
- Stimulating immunity.
- Reducing cholesterol and triglycerides.
- Producing vitamins such as vitamin K.
- Limiting pathogenic bacteria.
- Producing antioxidants.
What are the prebiotic functions?
- Feeding beneficial flora and stimulating growth.
- Promoting bacterial fermentation and short-chain fatty acids supporting intestinal mucosa.
- Regulating bowel movements by increasing bacteria and moisture, supporting appropriate stool bulk and digestive-tract movement.
- Reducing colon tumour risk by limiting compounds promoting tumour-cell growth.
- Lowering pH, increasing acidity in the intestine.
- Supporting production of vitamins the body cannot make alone.
- Supporting the immune system.
These explain why probiotics and prebiotics matter.
Which Foods Contain Them?
Many everyday foods can help.
Probiotic Foods
- Yoghurt: strain content varies, and not every yoghurt is rich in probiotics.
- Kefir: similar to yoghurt, with potentially three times more probiotics in this comparison.
- Fermented vegetables such as sauerkraut and kimchi, or other pickled vegetables.
Prebiotic Foods
- Leeks provide prebiotic inulin.
- Maize, potatoes, sweet potatoes, bananas and oats supply resistant starch.
- Soya contains oligosaccharides supporting colonic bacteria.
- Apples and onions provide prebiotic pectins.
- Pulses such as red lentils combine resistant starch and soluble fibre.
- Nuts, particularly walnuts.
Probiotics and Prebiotics for Athletes
Athletes fear illness during training or competition, where infection can disrupt preparation and performance despite substantial effort.
Evidence does not show probiotics and prebiotics directly improving performance, but suggests roles in illness prevention and reducing digestive symptoms.
The group athletes in cycling, swimming, rowing, triathlon and mountain ultras or other long-distance sports may experience more upper respiratory infections during intense training.
These infections relate to exercise-induced changes in immunity that can favour pathogens. However, upper respiratory symptoms may be non-infectious, arising from mechanical irritation during hyperventilation or inhaled particles, triggering inflammation that disrupts training or competition.
The problem gastrointestinal discomfort is also common in athletes through fuelling, travel or diet changes.
Consequently, athletes increasingly explore these products to improve resistance to infection and reduce illness risk affecting performance.
Use probiotics and prebiotics under professional guidance because gas and cramps may occur, often improving as the body adapts.
The intake of probiotic and prebiotic foods should accompany a varied, balanced diet for good nutrition and quality of life.
Recipe Ideas
Now you know probiotic and prebiotic sources, try including them daily.
How about kefir with oats, apple and walnuts, or lentils with potato, leek and sauerkraut?
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