Bread Sourdough Lactic Acid Bacteria—Technological, Antimicrobial, Toxin-Degrading, Immune System-, and Faecal Microbiota-Modelling Biological Agents for the Preparation of Food, Nutraceuticals and Feed

This review intends to highlight the fact that bread sourdough is a very promising source of technological, antimicrobial, toxin-degrading, immune system-, and faecal microbiota-modelling biological agents for the preparation of food, nutraceuticals, and feed, which has great potential at industrial biotechnology scale. There are many applications of sourdough lactic acid bacteria (LAB), which are the main microorganisms in spontaneous sourdough. In addition to their application as pure technological strains in the food and feed industries, taking into consideration the specific properties of these microorganisms (antimicrobial, antifungal, immuno-, and microbiota-modulating, etc.), they are used as valuable ingredients in higher-value food as well as nutraceutical formulations. Additionally, a very promising application of LAB is their use in combination with plant- and/or animal-based ingredients to increase the functional properties of the whole combination due to different mechanisms of action, as well as desirable symbiotic activity. In addition to traditional foods prepared using sourdough microorganisms (bread, biscuits, meat products, dairy, beverages, etc.), they could find application in the preparation of added-value ingredients for the food, nutraceutical, and feed industries. Finally, this mini-review gives a brief introduction to the possible applications of sourdough LAB in the food, feed, and nutraceutical industries.