Long-Fermented Sourdough: A Bread That Makes Fiber Absorbable and Easy on Your Gut

Authentic sourdough bread may be a healthy option for some people with gluten sensitivity, experts say.

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Sourdough is the oldest form of leavened bread, dating back to at least 2000 B.C. when ancient Egyptians likely discovered it by accident. Wild yeast and bacteria may have drifted into dough left out to rest, triggering fermentation. The result? A naturally leavened bread with better flavor, texture, and—as we now know—several health benefits.

The fermentation process enhances digestibility and boosts fiber content. Some people with non-celiac gluten sensitivity may find sourdough easier to tolerate since fermentation helps break down gluten proteins. However, not all sourdough is created equal—it’s important to choose traditional, long-fermented varieties to reap these benefits.

Long-Fermented Sourdough Bread

Sourdough bread is created using a two-step fermentation process. Flour is mixed with water and yeast and allowed to ferment.

“Sourdough differs from store-bought bread primarily in its fermentation process,” Chantelle van der Merwe, a registered dietitian, told The Epoch Times. Unlike most commercial bread, which uses fast-acting yeast for quick fermentation, sourdough undergoes a slow fermentation process that can take several hours to days. This extended fermentation enhances its flavor, giving it a distinct tangy taste in addition to nutritional benefits, she added.

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“Sourdough starters can remain active for years or even decades with regular feedings of flour and water,” Julie Stefanski, a registered dietitian nutritionist, told The Epoch Times.

As the starter ferments, it naturally collects wild yeast and beneficial bacteria from its environment, making each batch unique to its place of origin. This long fermentation process also begins breaking down components of the wheat, potentially making the bread easier to digest, Stefanski said.

Health Benefits

The fermentation process has multiple benefits, including enhancing the nutritional quality of bread, increasing fiber and antioxidant levels, and reducing FODMAPs. These are the fermentable carbohydrates found in foods like wheat, beans, and certain fruits that can trigger digestive issues in some people, especially those with irritable bowel syndrome.

Sourdough fermentation enhances fiber availability and digestibility. It makes the fiber more absorbable and accessible by breaking down the components that make it harder to digest. The fermentation process activates enzymes that break down the tough cell walls of the grains, improving fiber digestibility. Sourdough fermentation also converts some fiber into forms that can feed beneficial gut bacteria, supporting digestion and gut health.

During long fermentation, complex molecules like proteins and starches are broken down into simpler forms, making certain compounds and minerals more bioavailable (easier to absorb and use), nutritious, and digestible. The bioavailability of minerals such as iron and zinc is also enhanced by 10 percent and 25 percent, respectively, with fermentation.

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Compared with regular yeast fermentation, sourdough fermentation has also been shown to increase the amount of resistant starch by up to 120 percent. Resistant starch is a type of starch that isn’t digested in the small intestine, instead traveling to the large intestine, where it is fermented by gut bacteria. This type of starch offers many health benefits, including improved gut health, a balanced gut microbiome, better nutrient absorption, and lower insulin and glucose levels.

People with non-celiac gluten sensitivity may find sourdough bread easier to tolerate. The long fermentation process helps break down gluten. Sourdough disrupts the gluten protein network by breaking it into smaller, more digestible units. During fermentation, enzymes like proteases are also produced helping to partially break down gluten and modify its structure, making it more digestible and causing fewer gut symptoms.

It’s important to note, however, that some people who experience discomfort after eating gluten may actually have celiac disease rather than just a gluten intolerance, as the symptoms of both conditions are similar. Those with celiac disease should avoid all forms of wheat, whether sourdough bread or a plain white roll. If you experience discomfort with wheat, it’s crucial to get tested for celiac disease, Stefanski advised.

How to Identify Authentic Sourdough

To ensure you’re getting true sourdough, it’s important to look for breads made with traditional methods and long fermentation. Many breads labeled as sourdough are actually made with added yeast and shortcuts, not the wild yeast and bacteria that define authentic sourdough. Getting the real deal is crucial, as these shortcuts can affect the bread’s flavor, texture, and health benefits.

“Authentic sourdough bread should have a simple ingredient list and a distinct flavor and texture,” said van der Merwe.

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Authentic sourdough typically has a denser crumb and a chewy, well-developed crust due to its slow fermentation process and higher hydration levels. Real sourdough should only contain flour, water, and salt, without added commercial yeast or preservatives. Many store-bought “sourdough” breads use sourdough flavoring or a small amount of starter combined with commercial yeast, she added.

The best way to find out about your bread’s origin is to ask bakery staff or check the company’s website, said Stefanksi. Since the fermentation process is long and not the most profitable approach for a company, they are likely to highlight their authentic processes on their website or social media.

Topping Ideas

Adding nutritious toppings to sourdough enhances its flavor and boosts its health benefits.

One of van der Merwe’s favorite combinations is avocado, hummus, and cottage cheese, seasoned with lemon juice, salt, and pepper. The healthy fats in avocado and hummus help facilitate smooth digestion, while the probiotics in cottage cheese aid in nutrient absorption.

For a more unusual topping, Stefanski discovered cranberry sauce paired with a dairy product like cream cheese, cottage cheese, or yogurt. The tartness of the cranberries, combined with the protein and probiotics in the dairy, creates a balanced, gut-friendly topping that complements sourdough’s natural ability to support digestion.