Sourdough-Omics: Modern Analytical Approaches to Understanding an Ancient Fermented Food

Sourdough fermentation is an ancient food processing technology wherein wild bacteria and yeasts leaven dough in baked goods like breads. Known as “starter cultures”, the communities of bacteria and yeast used to inoculate dough can be generated de novo from the growth of microorganisms endogenous to the flour and water used to create dough, then re-used continuously in food production. Despite its longevity in the food system, relatively little is known about how unique sourdough starter cultures influence bread quality, safety and nutrition. By combining empirical food quality methods with amplicon sequencing and untargeted metabolomics, we have characterized key relationships between quality outcomes and individual microbial populations, as well as those between bioactive metabolites and predicted metabolic functions of starter culture communities as a whole. These findings provide critical insight towards the development of targeted processing approaches to produce more functional and sustainable bread products that meet the needs of modern consumers.