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Prebiotics vs probiotics: differences, benefits and foods

prebiotics vs probiotics - image shows a variety of probiotic foods
(Image credit: Getty Images)

Prebiotics vs probiotics: which are better for gastrointestinal health? A healthy gut plays a major role in our overall health and wellbeing, and taking prebiotics and probiotics – either in food or supplement form – is one way to boost the digestive system and keep it working efficiently.

The gut microbiome consists of 100 trillion live bacterial microbes, both ‘good’ and ‘bad’, that influence nutrient absorption, metabolism, immunity, mental health, how well we sleep and even whether or not we get spots. A Harvard Medical School study (opens in new tab) found that a healthy gut could potentially also prevent some cancers and autoimmune diseases. 

Meanwhile, research from the University of Tsukuba (opens in new tab) in Japan suggests that a healthy gut can improve sleep quality. It found that gut bacteria might influence sleep patterns by helping to create important chemical messengers in the brain, such as mood-boosting serotonin and dopamine.

Here, we’ll take a closer look at prebiotics vs probiotics, what the key differences are between them, and how they can both benefit us. 

Prebiotics vs probiotics: what’s the difference?

“Probiotics are beneficial or ‘good’ live bacteria that have the ability to restore and improve your gut microbiome, or gut flora,” says gut health specialist Marilia Chamon, founder of Gutfulness Nutrition (opens in new tab). “You can find them in food and drink, or take them in pill or powder form.”

“Prebiotics, on the other hand, are non-digestible dietary fiber that act as food for good gut bacteria. You can find them in certain foods or supplements. Probiotics are transient, meaning they will survive in the gut for a short period of time, but do not set up residency. By feeding them prebiotic fiber, we give them the fuel they need to colonize the gut and improve digestive health.”

You can read more about gut health and why it's important for a more general  overview.

Prebiotics vs probiotics: where can you find them?

Chamon recommends eating a variety of the following foods to gain prebiotics. Each contains unique fibers which the different microbes in your gut like to feed on. This is one of the best ways to increase your microbial biodiversity, which is crucial for a healthy gut.

  • Artichokes
  • Onions
  • Garlic
  • Asparagus
  • Leeks
  • Unripe/green bananas

For probiotics, Chamon advises consuming a variety of cultured and fermented foods, including those listed below. 

  • Yogurt
  • Kefir
  • Sauerkraut
  • Kimchi
  • Miso
  • Kombucha
  • Pickles

“These are a dietary source of live bacteria that can favorably alter the gut’s microbial balance,” she says. “This is because they offer high concentrations of digestive enzymes – produced during the fermentation process by microorganisms in the food – so they can assist with the digestion of simple and complex carbohydrates including fiber, proteins and fats.”

Is it better to take a prebiotic or probiotic?

It’s perfectly fine to take prebiotics and probiotics together, a practice known as microbiome therapy (opens in new tab). You don’t need prebiotics for probiotics to work, but it might make them more effective. In fact, one 2020 study (opens in new tab) suggested doing this could even help to treat obesity. 

But when is it best to opt for a prebiotic vs probiotic? “Probiotic-rich foods can help to improve gut bacteria diversity and taking supplements can be used as a therapeutic tool to address specific symptoms, for example: bloating, constipation, diarrhea,” says Chamon.

She recommends, however, only using specific strains of probiotics that have been researched and proven to help with certain gut-related symptoms.

“Prebiotics, on the other hand, feed probiotics – for this reason, it is important to eat a varied plant-oriented diet, rich in prebiotic fiber. Prebiotic supplementation can also be helpful for those that struggle to eat enough fiber, with daily recommended intake in the US being 25-30g.”

What are postbiotics?

“Postbiotics are beneficial compounds made when the friendly bacteria in your gut – probiotics – digest and break down dietary fiber – prebiotics,” explains Chamon. “Some of the most important postbiotics are called Short Chain Fatty Acids (SCFAs) and these play important roles in our gut health by keeping the gut environment stable and nourishing beneficial bacteria. They also stop opportunistic bacteria from entering our intestinal ecosystem and sticking around.”

Maddy is a freelance journalist and Level 3 personal trainer specializing in fitness, health and wellbeing content. She has been a writer and editor for 22 years, and has worked for some of the UK's bestselling newspapers and women’s magazines, including Marie Claire, The Sunday Times and Women's Health. Maddy loves HIIT training and can often be found working out while her two young daughters do matching burpees or star jumps. As a massive foodie, she loves cooking and trying out new healthy recipes (especially ones with hidden vegetables so the kids eat them).