While the gluten-free diet is still the only treatment for celiac disease, research is ongoing all over the world trying to find a way to modify gluten in wheat so that people with CD can eat it, for example in breads. This would make the diet much more palatable. Many people with celiac disease miss the consistency of normal bread. Bread made with other flours is often not a satisfying replacement.
It is known that certain parts of the gluten in wheat trigger the immune response in celiac disease that leads to symptoms and damage. It is possible to add ingredients that break down the problematic parts of gluten when making sourdough bread from wheat flour.
Researchers in Italy have discovered a number of important things about wheat, sourdough bread, and gluten. Older baking methods have provided some answers. Perhaps some of the modern ways to make bread are contributing to the rise in celiac disease.
In the past, bread was always leavened by biological agents, which meant that aeration of the dough was accomplished either by lactobacilli bacteria or cultivated yeasts. Bread made with lactobacilli develops a sour taste because lactic acid is made during the leavening. The leavened dough containing the bacteria was called old dough, or mother dough. This is where the lactobacilli were.
More flour dough was added and mixed or kneaded. The dough would sit for the process to occur that puts air into the dough. Part of a batch of sourdough could be saved when the rest was baked. This could be starter dough for the next bread. During the time that the dough rested, lactobacilli were breaking down the gluten.
In many countries, leavening is now not usually done with lactobacilli, and most bread is not sourdough. Cultured yeast is usually the leavening agent. Certainly sourdough is still made, but it is believed to be made somewhat differently from times past, when the dough may have rested for longer periods.
Scientists now know which parts of the gluten protein contain the sequences of amino acids which trigger cells in the intestinal walls of patients with celiac disease to release harmful chemicals. They can do a number of tests to look for these parts of gluten.
One group of researchers wanted to see if they could use lactobacilli known to be able to break down the proteins in wheat, including gluten, in order to bake a more satisfactory but safe bread. This was a small test to see if this is practical and not dangerous.
Bread was made with gluten-free oats, millet and buckwheat, along with 30% wheat. This mix was felt to make bread satisfactory in taste and texture. Four types of lactobacilli were used for fermentation in one batch of bread, lactobacilli and their cellular extracts another, and a third with baker’s yeast. A control batch was acidified without any bacteria or yeast. All the tests were done on these dough mixtures that had been fermented. The tests all showed decreased evidence of the part of gluten that is toxic to patients with CD in the mixtures with lactobacilli.
Besides laboratory testing, two of these leavened mixtures were baked and given to people to eat.
One was made with baker’s yeast, the other with lactobacilli and cellular extracts. There was gluten in the wheat used to make the dough.
Seventeen patients with celiac disease who had been on a gluten-free diet for at least 2 years volunteered to try the bread. Their reactions to the bread were monitored by tests that indicate malabsorption, in order to detect if something was affecting their ability to absorb what they ate, in this case, something in the bread.
13 of the 17 had indications of decreased absorption when they ate the bread made with baker’s yeast. The same 13 did not show any decrease in absorption of nutrients with the bread made with lactobacilli. Four patients had normal tests after both breads.
This small study showed that bread made from a variety of flours together that includes wheat can be leavened with specific lactobacilli and their cellular extracts, allowed to sit, and after baking, be both palatable and apparently not toxic to celiac patients.
Another small study used baked goods made from wheat flour, fermenting the dough with either lactobacilli or fungal proteases. There were three groups of baked goods, one with a normal amount of gluten (200 grams), one with partially hydrolyzed gluten, and one with fully hydrolyzed gluten because of the lactobacilli.
The trial lasted sixty days, giving these baked goods to patients with celiac disease. The patients who ate baked goods with normal flour all had increased levels of anti-tTG antibodies and their small bowel biopsies were abnormal; 2 of the 6 patients stopped due to symptoms. Two patients who ate baked goods with partially hydrolyzed gluten developed subtotal atrophy on intestinal biopsy. Five patients who ate the fully hydrolyzed wheat flour felt normal, had no positive blood tests for celiac disease, and their small bowel biopsies were normal.
Much more work needs to be done. But it is heartening to think that researchers have been able to make good-tasting bread that people with celiac disease can eat.