Sourdough helps moderate the effects of phytates. All seeds develop phytates to ensure reproduction. During fermentation, sourdough breaks down phytates and makes grains, seeds, and nuts easier to digest and more nutritious.
Sourdough is not a solution for celiac disease, however, some people who have certain intolerances can have sourdough if it is properly made.
The information on phytates was cited from:
“Chapter 3: Sourdough Primer.” Sourdough: Recipes for Rustic Fermented Breads, Sweets, Savories, and More, by Sarah Owens, Roost Books, 2015, pp. 40.