Is Store Bought Sourdough Bread Low FODMAP?

October 21, 2025 •

4 min read

According to Monash University, the fermentation process can reduce the FODMAP content of sourdough bread, making certain types a better option for those with sensitive stomachs. This raises the critical question for many managing Irritable Bowel Syndrome (IBS): is store bought sourdough bread low FODMAP?

Quick Summary

Store bought sourdough bread can be low FODMAP, but it is not guaranteed. Authenticity depends on the fermentation process and specific ingredients used by the manufacturer. Consumers must inspect labels for a sourdough starter, suitable flour types like white wheat or spelt, and avoid high FODMAP additives for best results.

Key Points

Authenticity is Crucial: Only traditionally made sourdough bread that has undergone a long fermentation process is reliably low in FODMAPs, as the microbes break down the fructans.
Check the Ingredients: A true sourdough should list sourdough starter or culture. If it lists commercial yeast or vinegar, it may not be authentically fermented for low FODMAP purposes.
Flour Type Matters: Opt for sourdough made from wheat or spelt flour. Avoid varieties made with high-FODMAP flours like rye or kamut.
Seek Certification: The most reliable way to find a low FODMAP sourdough is to look for products certified by Monash University or another reputable organization.
Portion Control: Even with low FODMAP sourdough, portion sizes are important. Monash University recommends limiting servings to one or two slices, depending on the type of flour.

Understanding the 'Low FODMAP' Sourdough Exception

Wheat is traditionally a high-FODMAP food, primarily due to its fructan content, a type of fermentable carbohydrate. For individuals following a low FODMAP diet, this usually means avoiding most regular bread. Sourdough, however, represents a notable exception due to its unique preparation method. The defining characteristic of authentic sourdough is the long fermentation process, which utilizes wild yeast and lactic acid bacteria from a sourdough starter instead of commercial baker's yeast.

During this extended fermentation, the microorganisms in the starter actively consume the fructans in the flour, breaking them down into more easily digestible forms. This process significantly reduces the overall FODMAP content of the finished bread. Research from Monash University, a leading authority on the low FODMAP diet, has confirmed that traditionally made sourdough from wheat or spelt flours can be suitable for a low FODMAP diet within specific portion sizes. The key takeaway is that the low FODMAP nature of sourdough is not inherent to the bread itself, but a direct result of the long, traditional fermentation process.

The Commercial Sourdough Complication

This is where the distinction between artisanal bakery sourdough and commercially produced, store bought sourdough bread becomes crucial. Not all bread labeled 'sourdough' on supermarket shelves undergoes the long fermentation required to reduce FODMAP levels. Many mass-produced versions use commercial yeast to speed up the rising process, then add flavorings like vinegar to mimic the classic sourdough tang. This shortcut means the fructans are not sufficiently broken down, leaving the final product high in FODMAPs and potentially triggering IBS symptoms.

To ensure a store-bought loaf is likely low FODMAP, careful label reading is essential. You must look for explicit signs of a traditional process, such as 'sourdough starter' or 'sourdough culture' in the ingredients list, and avoid products with added yeast or high-FODMAP ingredients like honey or inulin. Some producers have even pursued formal low FODMAP certification, a process that involves independent laboratory testing to verify the product's FODMAP content.

How to Vet Store Bought Sourdough for FODMAPs

When at the grocery store, follow these steps to increase your chances of finding a low-FODMAP-friendly loaf:

Check the ingredients list: Look for simple, traditional ingredients like flour, water, salt, and sourdough starter. An ingredient list that also includes vinegar or commercial yeast is a red flag for a non-traditional process.
Ask the baker: If you're shopping at a grocery store with an in-house bakery, or at a small, local bakery, don't be afraid to ask about their process. Inquire about the fermentation time, specifically if they use a long, slow-rise method.
Look for certification: For maximum certainty, search for products with official low FODMAP certification, such as the Monash University certification label. This eliminates guesswork entirely.
Choose the right flour: Sourdough made from white wheat or spelt flour is generally a safer bet than other grain varieties. Rye and kamut sourdough, for instance, are high in FODMAPs regardless of the fermentation process.

Comparing Sourdough and Regular Breads

This table illustrates the key differences that impact the FODMAP content of breads, highlighting why sourdough is unique.


Characteristic	Traditionally Made Sourdough	Standard Commercial Bread	Gluten-Free Bread (read label)
Fermentation Process	Long, slow fermentation (often 12+ hours) using a live sourdough culture.	Rapid fermentation using commercial baker's yeast.	Varies widely by brand; some may have added high FODMAP ingredients.
Primary Fermenters	Wild yeast and lactic acid bacteria from the sourdough starter.	Commercial, fast-acting baker's yeast.	Often uses commercial yeast or chemical leaveners.
FODMAP Reduction	Significantly reduces fructan content by breaking down carbohydrates during fermentation.	Limited time for fructan breakdown, so high levels remain.	Contains no wheat-based FODMAPs, but check for other high FODMAP additives.
Primary Flour	Often white wheat or spelt, but can use other varieties.	Commonly high-fructan wheat flour.	Uses low-FODMAP flours like rice, corn, or oat flour.
Digestibility	Often easier to digest for those with IBS or fructan sensitivities.	Can cause significant digestive distress in sensitive individuals.	Digestibility depends on the specific ingredients and individual sensitivities.

Conclusion: Mindful Shopping is Key

While it's tempting to assume that any store bought sourdough bread is low FODMAP, the reality is more nuanced. The beneficial effect on FODMAP content is directly linked to the traditional, long fermentation process, which is not a standard practice for many commercial loaves. For individuals with IBS or other FODMAP sensitivities, being a discerning shopper is crucial. Prioritize products that explicitly list sourdough starter in their ingredients, verify the fermentation process with the baker if possible, or look for certified low FODMAP options. By taking these steps, you can confidently include sourdough bread in your diet and enjoy its unique flavor and texture without the digestive consequences of a high FODMAP load.

Reference

Monash University Low FODMAP Certified™ Products: https://www.monashfodmap.com/ibs-central/i-have-ibs/get-the-app/

Frequently Asked Questions

Sourdough bread can be low FODMAP because the long fermentation process, driven by a natural sourdough starter, allows wild yeasts and bacteria to 'predigest' and break down the fructans found in the flour, which are a common FODMAP trigger.

Traditional sourdough relies on a slow, natural fermentation process. Many commercial 'sourdough' loaves use commercial yeast and added flavorings to speed up production, skipping the long fermentation that breaks down FODMAPs effectively.

When looking for low FODMAP sourdough, avoid products with added commercial yeast, high-fructose corn syrup, honey, inulin, garlic, onion, or high-FODMAP flours like rye or kamut.

No. Sourdough fermentation reduces FODMAPs but does not remove the gluten. Individuals with celiac disease or a non-celiac gluten sensitivity must follow a strictly gluten-free diet and should not consume sourdough made with wheat or spelt flour.

Spelt flour is naturally lower in fructans than modern wheat, and the sourdough fermentation process reduces the remaining FODMAPs. However, it's still best to choose a spelt sourdough made with a traditional, long fermentation for the lowest FODMAP content.

Yes, even low FODMAP sourdough bread should be consumed in moderation. According to Monash University, a typical low FODMAP serving is two slices for wheat or spelt sourdough.

The most reliable method is to look for a product that has been independently tested and certified as low FODMAP, often displaying a certification label from an organization like Monash University.