Lactic Acid Bacteria: A functional approach

Abstract

Lactic Acid Bacteria have been used for centuries in the food and beverage industries, first for food preservation, but in the last century also because of their health benefits. They are regarded as GRAS (generally regarded as safe) organisms for human consumption, and even benefit human health as in the case of probiotics. Probiotics are defined as “Life microorganisms, which, when administered in adequate amounts, confer a health benefit to the host”. Despite several decades of research on probiotics, the mechanisms of action of the bacteria are still far from being elucidated or understood. Topics covered in this book include such simple things as ‘what is an adequate amount?’, and ‘are multi-strain products better than single-strain products’? Probably, because health effects are strain dependent, and diseases and disorders are multifactorial, there are no straightforward answers to even these fundamental questions (Chapter 2). Lactic acid bacteria can also be used to enrich the vitamin B status of foods, through in situ production (Chapter 7), or they can interact with vitamin D and its receptor, through influencing the gut microbiota and thereby induce immunomodulatory effects (Chapter 6). They can also impact gut diseases and disorders such as inflammatory bowel disease and irritable bowel syndrome (Chapter 10). But also diseases and disorders distant from the gut, such as cardiovascular diseases (Chapter 12) and associated with that, obesity (Chapter 9), have been shown to be modulated by probiotics. Moreover, it has recently been discovered that they influence the brain and neurodegenerative pathologies too (Chapter 11). Several possible modes of action have been entertained, which range from the production of antimicrobial peptides called bacteriocins (Chapter 5); cell-cell communication through the production of quorum sensing molecules (Chapter 1); through (modulation of) production of short-chain fatty acids which play a role in gut homeostasis (Chapter 8) or metabolites of polyphenols with anti-inflammatory or even anticancer activity (Chapter 13). Furthermore, lactic acid bacteria may impact the bioavailability and digestibility of food components, such as minerals or proteins (Chapter 3), and in one particular application may be used to decrease the allergenicity of food by fermenting the immunostimulatory epitopes (Chapter 4). Apart from human health, they also impact animal health (and if these are used for human food consumption, then indirectly also again human health; Chapter 15). And because of their versatility, they can even be used as biological sensors for improving food safety (Chapter 14) and preventing spoilage, amongst others through their production of bacteriocins and acids. In this timely book, expert international authors have reviewed these selected hottopics to provide an up-to-date overview. This book is essential reading for everyone aiming to functionally apply lactic acid bacteria/probiotics for human health, from the PhD student to the experienced scientist.