Does sourdough bread contain probiotics or prebiotics?

Written by: Kari Raman, PharmD, RPh
Published July 3, 2023

I used to work as a pharmacist in San Francisco, home of sourdough bread. I heard a lot of amazing things about sourdough bread, and tasted some amazing things too! When I first started working in the pharmacy, patients would ask (or sometimes state) about the health benefits of sourdough. 

Well, I decided to look into it and answer two of the most common questions I’d hear in the pharmacy about SF’s local bread: 1) does sourdough bread contain probiotics and 2) does sourdough bread have prebiotics.

Sourdough dough – the uncooked bread – has bacteria

Sourdough bread is made using a fermentation process that includes lactic acid bacteria and yeast. These organisms work together in a symbiotic relationship to ferment the dough, which gives the bread its characteristic tangy taste. 

When it comes to probiotics, these bacteria can indeed be a part of the sourdough culture (also known as the “starter”). So that’s the uncooked bread – some of my friends got into making this kind of bread at home, and they have these funny little dough balls in a bowl on their counter. It’s actually alive, well, to be more specific, has living bacteria in it. 

Does Sourdough bread have probiotics?

Baked sourdough bread does not have living probiotics. The baking process, which involves high temperatures, typically kills these bacteria. Therefore, although the dough does contain live cultures during the fermentation process, the finished baked bread is not a source of live probiotics. It is freaking delicious though!

Does Sourdough bread have prebiotics?

Yes, sourdough bread can be a source of prebiotics. Prebiotics are types of dietary fiber that feed the friendly bacteria in your gut, helping them to produce nutrients for your body.

The main prebiotic in sourdough bread is a type of resistant starch that remains after the baking process. This type of starch isn’t fully broken down and absorbed in your stomach or small intestine. Instead, it makes its way to your large intestine, where it feeds the beneficial bacteria in your gut.

It’s also worth noting that the fermentation process involved in making sourdough bread can modify the structure of the bread’s starches, making them more resistant to digestion. This can potentially increase the prebiotic content of the bread. However, the actual prebiotic content can vary based on factors such as the type of flour used, the specific process of fermentation, and the baking process.

In addition to resistant starch, sourdough bread made from whole grains can also contain other types of dietary fiber that act as prebiotics. So, while sourdough doesn’t contain live probiotics after baking, it can support gut health by providing prebiotic fiber that nourishes the beneficial bacteria in your gut. Whole wheats are one of the best sources of healthy foods for your gut microbiome, so the right bread can help. Of course, eating too many carbs can help you pack on the pounds, so everything in moderation! 

Why Probiotics and Prebiotics are Good for Your Health

While baking sourdough bread might not be the first thing that comes to mind when thinking about your gut health, it is worth considering. The science behind sourdough fermentation is quite fascinating, with the interaction of wild yeasts and bacteria creating that distinct sourdough tang and texture. But beyond creating delicious bread, this process can have potential health benefits linked to the world of probiotics and prebiotics. And this is what I’m going to talk about now.

First things first, let’s discuss the basics. 

Probiotics, like Lactobacillus acidophilus (I wrote an entire article on L. acidophilus), are beneficial bacteria that may contribute to a healthy gut microbiota. Your gut houses trillions of these tiny organisms, including bacteria, viruses, and fungi. But don’t be alarmed – many of these are beneficial and play a crucial role in digestion, nutrient absorption, and the functioning of our immune system. 

By taking probiotics, either in the form of food or supplements, we can help maintain a healthy balance of gut bacteria. They can aid in crowding out harmful bacteria, reducing inflammation, and improving digestion. They’ve also been linked to improved immune function and may alleviate symptoms of conditions such as irritable bowel syndrome (IBS), lactose intolerance, and certain types of diarrhea.

On the other hand, prebiotics are substances that our bodies can’t digest, but serve as food for the beneficial bacteria in our gut. Essentially, they help our good bacteria to thrive. They’re typically fiber or complex carbohydrates found in foods like whole grains, bananas, onions, garlic, and indeed, sourdough bread.

Including prebiotics in our diet can enhance the benefits of probiotics. They stimulate the growth and activity of beneficial bacteria, helping to maintain a healthy balance of gut flora. Evidence suggests that a diet rich in prebiotics may reduce the risk of certain diseases, promote better overall digestive health, boost the immune system, and even enhance nutrient absorption.

Now, you might be wondering – what does all of this have to do with sourdough bread?

Well, during the fermentation process that makes sourdough so uniquely tasty, the lactic acid bacteria present in the sourdough starter feed on the flour’s starches, producing lactic acid (which gives the bread its sour taste). But… the baking process kills off these bacteria, so they can’t function as a probiotic when you eat your tasty sourdough bread and sip your wine. 

On the other, healthier, hand, sourdough bread is a source of prebiotics. The fermentation process also breaks down some of the gluten, making it easier to digest for some people. Whole grain sourdough, in particular, is high in fiber, acting as a prebiotic and promoting gut health.

Maintaining a healthy balance of gut bacteria is crucial for our overall health. Probiotics and prebiotics play a vital role in achieving this balance. So, the next time you’re enjoying a slice of sourdough bread, know that you’re not just delighting your taste buds, but you’re also taking a step towards better gut health. Just save some for me!

Pharmacist Kari Raman

I’m Kari Raman PharmD, RPh, and I am a licensed, practicing pharmacist. I hold a Doctorate in Pharmacy from The University of the Pacific, and I’ve served patients in retail, compounding and hospital pharmacies.

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I hope Pharmacist Probiotics helps you find out if there is a type of probiotic that works for you!