Prebiotics and probiotics sound similar, but they are not the same thing. Probiotics are live microorganisms that may provide a health benefit when consumed in adequate amounts. Prebiotics are substances used by microorganisms in the body that can provide a health benefit.
A simple way to remember the difference is that probiotics are selected microorganisms, while prebiotics are materials that certain microorganisms can use.
What are probiotics?
Probiotics are mainly bacteria, although some yeasts can also be probiotics. They are found in certain fermented foods and dietary supplements.
The word probiotic should not be treated as one universal ingredient. Effects can depend on the exact genus, species, strain, amount, storage conditions, and health question. A finding for one strain cannot automatically be applied to another product.
What are prebiotics?
Many prebiotics are types of fermentable carbohydrate or fiber. Examples include inulin, fructooligosaccharides, and galactooligosaccharides. They can be used by organisms in the gut and may influence the intestinal environment.
Not every fiber is officially considered a prebiotic, and a substance needs evidence of a health benefit connected with its use by host microorganisms.
What about fermented foods?
Yogurt, kefir, kimchi, sauerkraut, and other fermented foods can contain live organisms. A fermented food is not automatically a probiotic food. To call specific organisms probiotics, researchers need to identify them and connect an adequate amount with a demonstrated benefit.
Can you take prebiotics and probiotics together?
Yes. A product that combines them is sometimes called a synbiotic. Combining ingredients does not guarantee a stronger result. The specific organisms, prebiotic material, amounts, and evidence still matter.
How do you read a probiotic label?
Look for the complete organism name, including strain when available. Check the number of colony forming units, the date through which that amount is guaranteed, storage directions, serving size, and other ingredients.
A very large number on the label is not automatically better. The useful amount depends on the strain and intended use.
Possible side effects
Gas and digestive changes can occur, particularly when starting a fermentable prebiotic. Increasing the amount gradually may be easier for some people.
Probiotics are generally considered safe for many healthy people, but risk can be different for someone who is severely ill, has a weakened immune system, has a central venous catheter, or was born prematurely. Those situations require medical guidance.
Do probiotics interact with medicine?
The NIH notes that probiotics are not known for common medicine interactions, but antibiotics and antifungal medicines can reduce the effectiveness of some probiotic organisms. A clinician or pharmacist can help with timing.
Review the label for Fitness First Nutrition Probiotic 40 Billion with Prebiotics.
Trusted sources
- NIH Office of Dietary Supplements probiotics fact sheet for health professionals
- NIH probiotics fact sheet for consumers
Digestive symptoms can have many causes. Seek medical care for severe, persistent, or concerning symptoms.