Can I eat sourdough bread on FODMAP?

According to Monash University, the fermentation process of traditional sourdough breaks down much of the fructan content, which are the main FODMAPs found in wheat. This unique process means that yes, you can eat sourdough bread on FODMAP, provided you choose the right type and stick to specific serving sizes.

Quick Summary

Authentic sourdough bread can be low FODMAP because its long fermentation process reduces fructans. The key is choosing the right flour and ensuring a traditional, slow-rise method was used, as some commercial loaves are not suitable.

Key Points

• Fermentation Reduces FODMAPs: The long, slow fermentation process of traditional sourdough significantly reduces the fructan content, making it easier to digest than regular bread.

• Choose the Right Type: Opt for sourdough made from white wheat, wholemeal wheat, or spelt flour, which have been tested and found to be low FODMAP in specific serving sizes.

• Beware of 'Sourdough Style': Many supermarket breads labeled 'sourdough' use commercial yeast and have a quick rise, meaning they are not truly low FODMAP.

• Follow Serving Sizes: Even for low FODMAP varieties, portion control is important. For example, white wheat sourdough is low FODMAP at two slices per meal.

• Check Ingredients Carefully: A genuine low FODMAP sourdough should ideally contain only flour, water, and salt. Avoid products with added yeast, high FODMAP sweeteners, or rye flour during the elimination phase.

• Consider Baking Your Own: For complete control over ingredients and fermentation time, baking your own sourdough ensures it is genuinely low FODMAP.

The Fermentation Difference: Why Sourdough Can Be Low FODMAP

The reason certain sourdough breads are considered low FODMAP lies entirely in their production method. Regular bread relies on commercial yeast for a quick rise, which doesn't give the naturally occurring fructans in wheat flour enough time to break down. Fructans are a type of oligosaccharide (the 'O' in FODMAP) that can cause digestive issues for individuals with irritable bowel syndrome (IBS).

Traditional sourdough, on the other hand, uses a sourdough starter—a culture of wild yeast and lactic acid bacteria—to leaven the bread slowly over a period of 12 hours or more. During this prolonged fermentation, the beneficial bacteria consume and break down the fructans and other carbohydrates in the flour. The result is a finished product with a significantly reduced FODMAP content, making it much easier to digest for sensitive individuals.

How to Identify Authentic, Low FODMAP Sourdough

To ensure you're getting a genuine low FODMAP product, you need to be a savvy shopper. A loaf labeled simply 'sourdough' at a major supermarket may not be made with the traditional long fermentation process. Here are some tips for finding the real deal:

• Check the ingredients list: A true sourdough should contain only flour, water, and salt. If you see commercial yeast or added sweeteners like honey, it's likely a quick-rise bread and not suitable for a low FODMAP diet.
• Ask your baker: Local bakeries often use traditional methods. Don't hesitate to ask them about their leavening process and how long the dough ferments. A fermentation time of 12-24 hours is a good indicator of a low FODMAP loaf.
• Look for certification: Products certified by Monash University are lab-tested and confirmed to be low FODMAP at the recommended serving size.
• Avoid certain flours: While wheat sourdough can be low FODMAP due to fermentation, some flours remain high in FODMAPs even after the process. Avoid sourdough made with rye or kamut flour during the elimination phase.

Low FODMAP Sourdough Varieties and Serving Sizes

Different types of flour used for sourdough can influence the final FODMAP content. The serving sizes below are based on Monash University's testing and are important to follow, especially during the elimination phase of the diet.

• White Wheat Sourdough: Low FODMAP at a serving size of 2 slices (109g).
• Wholemeal Wheat Sourdough: Low FODMAP at a serving size of 2 slices (97g).
• Spelt Sourdough: Low FODMAP at a serving size of 2 slices, especially those with a higher percentage of spelt flour.
• Gluten-Free Sourdough: Often a safe choice, but should still be made with a long fermentation process and checked for high FODMAP ingredients.

Comparison: Sourdough vs. Regular Bread on a FODMAP Diet

Feature	Traditional Sourdough Bread	Regular Commercial Bread
Leavening Agent	Wild yeast and lactic acid bacteria in a sourdough starter.	Commercial baker's yeast.
Fermentation Time	Long, slow process (typically >12 hours).	Short, rapid process (a few hours).
FODMAP Content	Significantly reduced fructans and other FODMAPs.	High in fructans, as they are not fully broken down.
Digestibility	Easier on the gut for those with IBS due to lower FODMAPs.	Can trigger IBS symptoms like bloating and gas due to high FODMAPs.
Nutrient Absorption	Lower phytate levels can lead to better absorption of minerals.	Higher phytate levels can inhibit mineral absorption.

Making Your Own Low FODMAP Sourdough

For those who enjoy baking, making your own sourdough is the best way to control all the ingredients and ensure a long fermentation. You will need a sourdough starter, which can be purchased or cultivated at home. Once you have an active starter, the process is straightforward:

1. Feed your starter: Combine a portion of your starter with fresh flour and water. Allow it to become active and bubbly over several hours.
2. Mix and ferment: Combine the active starter with the rest of your flour, water, and salt. Allow the dough to ferment at room temperature for an extended period (12-24 hours) to properly break down the fructans.
3. Bake: Shape and bake your bread as usual. The long fermentation does the crucial work for you.

By following this method, you can be certain your bread is traditionally fermented and low in FODMAPs, free from any hidden ingredients that could cause digestive upset.

Conclusion

For individuals following a low FODMAP diet, the question of whether they can eat sourdough bread has a positive answer, but with important caveats. The traditional, long fermentation process is the key to reducing the fructan content that often triggers symptoms in IBS patients. By choosing a genuine sourdough made with white wheat, spelt, or wholemeal wheat flour, and adhering to the recommended serving sizes, it is possible to enjoy this flavorful and gut-friendly bread. Always check the ingredients and consider sourcing from local bakeries or making your own to avoid 'sourdough style' products with a shorter fermentation time. Sourdough offers a delicious way to reintroduce bread into your diet during the reintroduction or personalization phases of the FODMAP journey.

For further information on the low FODMAP diet, consider consulting the Monash University Low FODMAP Diet app.

Frequently Asked Questions

Why is sourdough bread low FODMAP when wheat is high FODMAP?

Wheat itself is high in FODMAPs (specifically fructans), but the long fermentation process used in traditional sourdough production allows the wild yeast and bacteria to break down and consume these fructans, reducing the overall FODMAP content.

How can I tell if a store-bought sourdough is truly low FODMAP?

Look for a product that is certified low FODMAP by a reputable source like Monash University. If not certified, check the ingredients for a traditional starter and a simple list of ingredients like flour, water, and salt, with no commercial yeast or high FODMAP sweeteners added.

What is the recommended serving size for low FODMAP sourdough?

According to Monash University, a standard serving for low FODMAP varieties like white wheat or spelt sourdough is two slices per meal. It is always wise to refer to the Monash app for the most accurate and up-to-date guidance.

Can people with celiac disease eat sourdough bread?

No, individuals with celiac disease must avoid all gluten. While the fermentation process in sourdough can reduce gluten and fructans, it does not eliminate them entirely. A gluten-free diet is required for celiac patients.

Are all types of sourdough flour low FODMAP?

No. While white wheat and spelt sourdough are typically low FODMAP, some flours remain high in fructans even after fermentation. It is recommended to avoid varieties made with rye or kamut during the elimination phase.

Is there a difference in FODMAP content between homemade and commercial sourdough?

Yes. Homemade sourdough or that from an artisan bakery is more likely to be genuinely low FODMAP, as it typically undergoes a traditional, long fermentation. Many mass-produced supermarket varieties use quick-rise methods that do not sufficiently reduce FODMAPs.

Does added yeast in sourdough make it high FODMAP?

Some commercially produced sourdoughs add baker's yeast to speed up the process, which can result in insufficient FODMAP breakdown. However, some low FODMAP certified sourdoughs do contain added yeast, so it is best to verify if the product is traditionally fermented or certified low FODMAP.