The Gluten-Free Fiber Gap: Why This Dietitian Recommends Gum-Free Sourdough

“I went gluten-free, and now I’m constipated.” As a registered dietitian who works with clients managing celiac disease, non-celiac gluten sensitivity, and general gut health, I hear variations of that statement more often than almost anything else. It’s not a coincidence, and it’s not just you.

Research has consistently shown that gluten-free diets tend to be lower in fiber compared to diets that include gluten-containing grains. The reason for this is evident in the bread aisle. Most gluten-free flour alternatives—such as white rice, corn, tapioca, and potato starch—are refined starches.

While they can replicate the texture of wheat flour, they do not retain the fiber content. This is what I refer to as the “gluten-free fiber gap,” and it's the first thing I check for when a client provides me with their grocery list.

 

Why Standard Gluten-Free Diets Fall Short on Fiber

The Importance of Fiber

Fiber is often regarded as a nice-to-have nutrient, but it plays a crucial role in maintaining gut health. It feeds the beneficial bacteria in your gut microbiome, which ferment fiber into short-chain fatty acids. These fatty acids help to maintain the gut lining, regulate immune function, and reduce inflammation throughout the body.

According to the Dietary Guidelines for Americans, most adults need between 22 and 34 grams of fiber each day, depending on their age and sex. Unfortunately, many adults fall short of this target: approximately 90% of women and 97% of men do not meet the recommended intake on a standard diet. 

Lower Fiber in Gluten-Free Items

When a gluten-free diet is added to this, the fiber deficit tends to widen. Multiple studies comparing gluten-free diets to standard diets have found that gluten-free options often provide lower amounts of fiber, folate, and B vitamins, while containing higher levels of sugar and fat. This is often due to processed gluten-free products such as bread, crackers, and baked goods, which replace whole grains with refined starches.

For those aiming for gut health on a gluten-free diet, it's essential to prioritize fiber intake; it should not be treated as an afterthought.


Where Gum-Free Sourdough Fits In

Xanthan gum and similar hydrocolloids are commonly found in gluten-free bread because they serve the same purpose as gluten—holding the dough together and providing structure and stretch.

These additives are recognized as safe for consumption, and for most people, they pose no problems. It’s important to clarify that gums are not the enemy. I'm not here to demonize an ingredient that has been well-studied and is useful in many gluten-free baking recipes, including some products made by Bread SRSLY.

Digestive Ease

However, gums are also a type of soluble fiber that ferments quickly in the gut. For individuals with sensitive digestive systems, particularly those managing irritable bowel syndrome (IBS) or who are prone to bloating, this rapid fermentation can lead to increased gas and discomfort.

This is where gum-free sourdough has its advantages. Traditional sourdough fermentation has been shown to enhance the digestibility of bread by breaking down some of the harder-to-digest compounds during the lengthy fermentation process, even before the bread reaches your plate. 

When you combine this natural fermentation with a gum-free formula, you create bread that is easier to digest from the start—no need for an elimination diet.

If you have never experienced adverse reactions to gums, there’s no need to worry about what’s in your pantry. However, if you are among the many whose gut is sensitive to added gums, or if you prefer to achieve your bread’s texture through fermentation and fiber-rich flours rather than additives, it is worthwhile to seek out gum-free gluten-free bread.


Meet the Fiber MVP: Bread SRSLY’s Gum-Free Sandwich Rolls

I seek the ideal bread, and Bread SRSLY’s gum-free Sandwich Rolls meet my needs. With 5 grams of fiber per serving and no added gums, thanks to slow sourdough fermentation, they provide nearly a quarter of the daily fiber target for adult women.

Their XL loaf also offers 3 grams of fiber per serving, making it great for sandwiches or toast. For those rebuilding a gluten-free diet that supports digestion, I focus on fiber content, beneficial fermentation, and gum-free ingredients. This bread checks all the boxes.


5 Ways to Build a Higher-Fiber Gluten-Free Toast

Bread is only part of the fiber equation—what you choose to put on it also matters. Here are five topping combinations I recommend for clients who want their toast to contribute to their fiber intake, not just their calorie count:

  1. Raspberries + Almond Butter: Raspberries provide about 8 grams of fiber per cup, making them one of the highest-fiber fruits. Spread them on French toast made with gum-free sourdough for a delicious mix of fiber and protein that keeps you satisfied. Hot tip: you can use de-thawed frozen raspberries for this too, as a year-round snack. 
  2. Mashed Avocado + Hemp Seeds + Chili Flakes: Avocado offers healthy fats and fiber, while hemp seeds contribute plant protein and an extra fiber boost without altering the flavor. We call hemp seeds “sprinkles” in my house.
  3. Cottage Cheese + Sliced Pear + Cinnamon: Pears, especially with the skin on, are high in fiber. Adding cottage cheese provides protein to keep you full.
  4. Nut Butter + Chia Seeds + Banana: Chia seeds add about 5 grams of fiber per tablespoon, making this topping one of the easiest ways to enhance fiber in your pantry.
  5. Smashed White Beans + Olive Oil + Everything Bagel Seasoning: This surprising combination features white beans, a powerhouse of fiber and protein, and tastes more like savory bruschetta than a typical “diet” food.


Looking Ahead: How To Incorporate Fiber In Your Gluten-Free Diet

Going gluten-free doesn’t have to result in a lower fiber intake. It just requires a more careful reading of labels and a choice of products, such as gum-free sourdough, that are designed with fiber and digestion in mind, rather than just texture. Best of all, your gut will appreciate the difference.


Sources

  1. Evidence of high sugar intake, and low fibre and mineral intake, in the gluten-free diet — PubMed: https://pubmed.ncbi.nlm.nih.gov/20528829/
  2. Gluten-Free Diet Reduces Diet Quality and Increases Inflammatory Potential in Non-Celiac Healthy Women — PubMed: https://pubmed.ncbi.nlm.nih.gov/34516338/
  3. How Much Fiber Do You Need per Day? — Cleveland Clinic: https://health.clevelandclinic.org/how-much-fiber-per-day
  4. Dietary Fiber and the Human Gut Microbiota: Application of Evidence Mapping Methodology — NCBI/PMC: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5331556/
  5. Sourdough Fermentation as a Tool to Improve the Nutritional and Health-Promoting Properties of Its Derived Products — MDPI: https://www.mdpi.com/2311-5637/7/4/246
  6. The Role of Xanthan Gum and Hydroxypropyl Methylcellulose in Gluten-Free Bread — NCBI/PMC: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12802409/
  7. Getting Fiber While Avoiding Gluten — Harvard Health: https://www.health.harvard.edu/heart-health/getting-fiber-while-avoiding-gluten

 

About the Author

Whitney Stuart, MS, RDN, CDECS is a registered dietitian nutritionist and founder of Whitness Nutrition, a virtual private practice focused on nutritional counseling for sustainable health through food. 

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