Thousands of years ago humanity started agricultural practice and the domestication of cattle. Milk from farmed animals represented a good source of nutrients and liquid for hydration. The fermentation of milk provided a simple way to increase its shelf-life while improving its safety. From the initial accidental phenomenon of fermentation, humans learned to control these processes. Incorporating the controlled fermentation of milk in domestic practices of these primitive societies gave rise to a progressive diversification of dairy products, as influenced by habits of different ethnicities, geographical environments, and type of dairy farming. European-derived populations show lactase activity into adulthood, exhibiting selection for a lactase persistence haplotype [
Therefore, fermented dairy products have been linked to the human nutrition and progress from ancient times. Nowadays they continue to be fundamental components of a balanced western diet. A huge variety of fermented dairy products are now available for consumers. Although a small proportion of these products are homemade, most of them are produced industrially; indeed, the dairy industry, particularly of fermented products, is economically important in many countries. Fermented products are generally populated by a diverse microbiota that impacts human health. Knowledge of microorganisms inhabiting underexplored natural fermented dairy products and their potential effects in human health, mechanisms underlying beneficial or detrimental effects of such microorganisms, and research in new safe alternative technologies to thermal processes constitute matters of current interest in food and health research. This special issue aimed to shed light on the role that microorganisms present in dairy fermented products play in human health and disease.
This special issue comprises reviews and experimental articles. Editors present first a general overview of the current state of the art. Although the special issue was opened to both beneficial and harmful microorganisms, contributions received focused on “good bugs.” Articles cover the following items: mechanisms of beneficial action of probiotics, food safety, and technological aspects of lactic acid bacteria and probiotics.
Relating mechanisms of probiotic action, the contributions address different aspects of microorganisms from the genus
M. J. Saez-Lara et al. reviewed the degree of scientific evidence in randomized human clinical trials for benefits associated with the use of lactic acid bacteria and bifidobacteria in the prevention and treatment of inflammatory bowel disease (Crohn’s disease and ulcerative colitis) and other related diseases such as pouchitis and cholangitis.
Polyphenols are characterized by the presence of large multiples of phenol structural units that are synthesized by many vegetables as defense compounds. Many of them have antioxidant and other beneficial effects in human health. Finally the beneficial action of polyphenols greatly depends on the generation of bioactive compounds through their biotransformation by the intestinal microbiota. The addition of polyphenols to fermented dairy products deserves further research and development of technological applications. Two manuscripts reviewed the interaction of dietary polyphenols and the intestinal microbiota. M. Dueñas et al. analyzed the current knowledge on the modulation of the intestinal microbiota by these compounds from the point of view of the experimental approaches used. In contrast, L. Marín et al. explored the potentially beneficial action of dietary polyphenols as antiviral, antibacterial, and antiparasitic agents.
Five articles addressed technological aspects of beneficial microorganisms included in fermented dairy products, either by considering the behavior of probiotics during the manufacture process or by focusing towards the production of specific beneficial compounds by microorganisms during the elaboration of such products. J. M. Castro et al. reviewed aspects related to the potential of cheeses as probiotic carriers and some technological aspects related to the maintenance of the viability of probiotics in cheeses. An experimental contribution presented the development of a potential probiotic fresh cheese using two
Finally, three papers deal with the role of lactic acid bacteria in the safety of fermented dairy products. J. L. Arqués and colleagues review the antimicrobial activity against pathogens of lactic acid bacteria in dairy fermented products as well as in the gut after ingestion. In addition, two experimental articles address different aspects of safety in dairy products. Metagenomic analysis was used to characterize the presence of antibiotic resistance genes in the microbiota of a specific dairy fermented product,
This editorial presents a brief summary of the topics discussed in the articles published in this special issue. We hope readers will find useful information on the topics discussed here.
We express our deep gratitude to the reviewers of articles submitted to this special issue. We thank the authors for providing such highly valuable contributions to this special issue.