Fermented foods have been part of the human diet since ancient times, and have remained a staple food for centuries. This centuries-old use of fermentation is largely due to its inherent ability to improve the functional properties of grains, vegetables, and other crops, and transforming them into nutritious or palatable products.
In recent years fermented foods have become increasingly popular, as consumers have become more interested in their nutritional benefits. Coupled with the idea of improving health by modulating the gut microbiome, more and more consumers are increasing their intake of fermented foods. In this regard, fermented foods, fiber-rich diets, and functional ingredients (such as probiotics, prebiotics, and postbiotics) can be used as dietary solutions for those seeking health benefits.
One such fermented product is sourdough, a traditional process used to improve the properties of baked goods. Sourdough fermentation is renowned for its bread flavor and texture-enhancing properties, but also for the increasing number of reports of its health benefits, such as faster gastric emptying, lower glycemic responses, higher concentration of total free amino acids, and improved digestibility associated with the consumption of sourdough.
Sourdough bread is baked at a high temperature, which results in the inactivation of the live lactic acid bacteria and yeast that ferment the bread dough; therefore, some health benefits from consuming sourdough bread must come from the postbiotic compounds, mainly the cell fragments and/or the heat stable metabolic and secreted compounds (lactic acid, short chain fatty acids, bacteriocins, amino acids, flavonoids, and many others) that are produced during the fermentation of the bread dough.
Postbiotics are an emerging trend belonging to “biotics” alongside prebiotics and probiotics. They are derived from microorganisms that have the potential to confer health benefits but, unlike probiotics, do not require living cells to induce health effects. Although there is currently neither consensus definition of what postbiotics are, nor a clear regulatory framework to communicate about their health benefits, their “innate” nature of postbiotics makes them suitable solutions for fermented foods with various types of cell-destroying steps during food processing, such as pasteurization or baking.
FIg 1. Summary description of components of a postbiotic according to ISAPP.
At Puratos, as world experts in sourdough fermentation and driven by our moto of “Food Innovation For Good”, we have embarked on a mission to transform bread, a global staple food product, into a vehicle that delivers postbiotic compounds to help consumers maintain a healthy and stable gut microbiome. To this end, we are conducting extensive research in the field of postbiotics with the financial support of Vlaio in collaboration with Prof. Tom Van de Wiele (CMET) and Prof. Lynn Vanhaecke (LIMET) of Gent University to identify those bacteria and their components that can provide health benefits.
This collaborative project aims to develop a functional sourdough that can contribute to human gut health and beneficially modulate the gut microbiome. Puratos' extensive expertise in food starter cultures and sourdough fermentation combined with CMET's and LIMET’s expertise in in vitro human digestion models (such as the SHIME and M-SHIME) and metabolomics will enable us to develop a sourdough bread enriched with postbiotic compounds (SCFA, beta-glucans, exopolysaccharides, and others). The aim is to transform a staple food like bread into a healthier and gut-friendly product that contributes to the beneficial modulation of the human gut microbiome.
1 Marco M L, Sanders M E, Ganzle, M et al The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nat Rev Gastroenterol Hepatol 18, 196–208 (2021) https://doi.org/10.1038/s41575-020-00390-5
2 Pérez-Alvarado O, Zepeda-Hernández A, Garcia-Amezquita LE, Requena T, Vinderola G and García-Cayuela T (2022) Role of lactic acid bacteria and yeasts in sourdough fermentation during breadmaking: Evaluation of postbiotic-like components and health benefits. Front. Microbiol. 13:969460. doi: 10.3389/fmicb.2022.969460
3 Salminen, S., Collado, M.C., Endo, A. et al. The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics. Nat Rev Gastroenterol Hepatol 18, 649–667 (2021). https://doi.org/10.1038/s41575-021-00440-6
4 Scott E, De Paepe K, Van de Wiele T. Postbiotics and Their Health Modulatory Biomolecules. Biomolecules. 2022 Nov 4;12(11):1640. doi: 10.3390/biom12111640. PMID: 36358990; PMCID: PMC9688025.