If you are starting a low FODMAP diet and are confused about bread, you are not alone! Most types of bread are high in FODMAPs and may trigger bloating, gas, and GI discomfort. But what about sourdough bread? Is sourdough bread low FODMAP, and can you enjoy it on a low FODMAP diet?
As a dietitian specializing in FODMAPs and managing IBS, I often meet people who avoid all kinds of bread. This saddens me, as that is an unnecessary restriction. I want all my clients to enjoy as wide a variety of foods as possible without experiencing gut discomfort.
In this article, I explain what makes sourdough different, how to select authentic sourdough, and appropriate low FODMAP portion sizes.
Is Sourdough Bread Low FODMAP?
The short answer is yes! Sourdough is usually low FODMAP thanks to fermentation, the type of flour used, and the absence of high-FODMAP ingredients. Let’s dive in!
Fermentation lowers FODMAPs
An authentic sourdough is made through a long, slow fermentation process (typically 12-48 hours). This gives the natural yeast and bacteria in the sourdough culture time to break down the FODMAPs in the flour (called fructans), basically digesting them for you. That’s why sourdough is much lower in these fermentable carbohydrates.
Types of flour
But fermentation is not enough to lower the FODMAP content of bread. Some flours (such as rye, barley or oat) remain high in FODMAPs, even if the bread is made though the traditional fermentation process.
You want to select a bread that is made with wheat flour, white or whole wheat, or spelt flour. Spelt is an ancient variety of wheat that is naturally lower in FODMAPs.
High-FODMAP ingredients to avoid
Once you have a sourdough bread that is authentic and made with wheat or spelt flour, there is one more thing you need to check on the label. Some bakeries add other ingredients that are high FODMAPs. The most common are:
- Barley flour
- Malted barley
- High FODMAP sweeteners: honey, molasses, or agave (unless listed at the end of the ingredient list)
In addition, avoid breads that list vinegar, as that is how many manufacturers make a bread taste “sourdough” but don’t use the authentic fermentation process. These are usually the packaged breads you would find in the bread aisle of the grocery store.
Finally, you want to avoid bread that contains baker’s yeast or simply yeast. When yeast is used, the bread may not have gone through the long fermentation process needed to break down the FODMAPs.
Where to find an authentic sourdough bread
The easiest way to find authentic sourdough bread is to go to a local bakery, or the fresh bakery section of your grocery store. You can recognize it as the list of ingredients is usually very short: wheat or spelt flour, water, and salt. Sometimes, it will say “sourdough culture or starter” but it doesn’t have to.
Finally, the bread my not even be called “sourdough” but if the ingredient list is as above, you know that’s an authentic sourdough bread.
Portions suitable for a low FODMAP diet
As is often the case with FODMAPs, portion size matters! Sourdough bread is low FODMAP but not FODMAP-free. You can check the appropriate portions of different types of bread on the Monash FODMAP App). They are usually between 1 to 2 slices (about 1 oz each).
Is Sourdough Bread Low FODMAP? It’s a wrap!
Sourdough bread can absolutely be part of a low FODMAP diet, as long as it’s the real thing. Thanks to long fermentation, the right choice of flour, and a short ingredient list, authentic sourdough is easier on the gut than standard bread.
By learning how to spot true sourdough, avoiding high-FODMAP add-ins, and keeping portions in mind, you can enjoy bread without unnecessary restriction or digestive discomfort.
If, despite doing your best to follow a low FODMAP diet, you continue to struggle with IBS symptoms like bloating, abdominal pain, and unpredictable bowel movements, and want to learn how to find real, lasting relief, book your complimentary IBS Clarity Session.
We will review your symptoms and history and discuss the best next steps for you! You will come out of this call feeling relieved and hopeful that you can take control of your IBS.
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Published October 10, 2022. Updated January 26, 2026.
Antonella Dewell, MS, RDN | IBS Resolution Expert
Antonella Dewell is a registered dietitian and IBS specialist based in California. She has over 2 decades of experience working in clinical research at Stanford. Since 2018, she has been running a private practice. She helps people with IBS gain real, lasting relief from IBS symptoms in just 2-4 weeks without giving up all the foods they love, so they can stop feeling anxious around food and get back to fully enjoying food and life again.
