Dietary Fibers and Fermentation: Improving Digestibility through Biotechnological Approaches

Insoluble dietary fibers (IDF), including cellulose, hemicellulose, and lignin, play a critical role in gastrointestinal health, metabolic regulation, and chronic disease prevention. Despite their physiological benefits, IDFs exhibit low fermentability and limited bioavailability, which constrain their full potential in human nutrition and food technology. Recent advances in biotechnology have highlighted controlled fermentation as a promising strategy to enhance the functional properties of IDFs. Through the activity of specific microbial consortia, particularly lactic acid bacteria and yeasts, fermentation can improve the solubility, fermentability, and nutritional impact of these fibers. This chapter provides an overview of the classification, structure, and physiological roles of IDFs while exploring the application of controlled fermentation in improving their digestibility, especially in the context of cereal-based food systems such as bread. The integration of fermented fibers into bakery products may contribute to improved dough properties, increased nutritional value, and enhanced health outcomes, supporting broader dietary fiber intake recommendations.