What is the difference between a prebiotic and a probiotic?

4th November 2022

Our gut contains a complex ecosystem of microbes. Both prebiotics and probiotics can help encourage a healthy gut microbiome but what’s the difference between them?


Prebiotics are compounds that are selectively used by gut microbes and give us health benefits.

Prebiotics feed the good gut microbes in our gut. They stimulate growth amongst pre-existing beneficial bacteria.

Complex carbohydrates and fibre from fruit and vegetables such as whole-wheat breads, barley, quinoa, potatoes, oatmeal and beans are prebiotics because they promote these beneficial bacteria.

Adults in the UK only eat about two thirds of the recommend ended daily intake of fibre of 30g. Here at the Quadram Institute we’re looking at ways to help increase the quality of fibre in foods.

It’s not just fibre that can have a prebiotic effect.

Research here at the Quadram institute has studied the prebiotic effect of human milk sugars, finding that they may improve gut health of adults by making the gut lining less leaky.


While prebiotics are the compounds that feed beneficial gut microbes, probiotics are products that contain the beneficial live gut microbes themselves.

Proposed health benefits of probiotics include helping restore gut balance after the microbiome has been disturbed, anti-inflammatory activity, competitive exclusion of disease-causing microbes, and stimulating the immune system.

Our researchers at the Quadram Institute have shown how probiotics can improve the microbiome in premature babies.

Specific strains of probiotic bacteria given to preterm babies along with breast milk help shape their gut microbial populations to help them fight potential infections. The probiotic bacteria Bifidobacterium and Lactobacillus are associated with a healthy term infant gut.

The probiotics help the babies get the full benefits from digesting breast milk and could help these vulnerable babies survive and get the healthiest start in life.

To work successfully, supplementation needs to mimic the symbiotic relationship found in nature by using bacterial strains that can unlock the prebiotics in breast milk to establish a healthy population, and in doing so keep the baby healthy too.

The beneficial impact of probiotics has been studied in animals too. When a specific probiotic is given to young chicks, it stops a dangerous bacteria colonising their gut.

At the Quadram Institute we’re studying the relationship between food, gut biology and health to learn more about prebiotics and probiotics.

Related Targets

Targeting food composition

Food Composition

Targeting Future Foods

Future Foods

Targeting personalised nutrition

Personalised Nutrition

Targeting the understanding of the microbiome

Understanding the Microbiome

Related Research Areas

Research area: microbes and health

Gut Microbes and Health

Research area: Food innovation

Food Innovation and Health