Handbook of Prebiotics and Probiotics Ingredients: Health Benefits and Food Applications
Consequently, E. We ought however to keep in mind that E. Originally isolated from neonatal stools, characterized and named Bacterium coli commune by Theodor Escherich , reprinted in Escherich, , E. Nevertheless, clinical and preclinical beneficial effects of certain E. This chapter summarizes current advances in understanding geno- and phenotypic features that allow to discern the pathogen from the commensal or the probiotic E. Findings in this field highlighted how complex it sometimes is to establish a clear border between probiotic and pathogenic features within E.
Consequently, ready-made guidelines for the use of probiotic E. Enterococcus species present a diversity of genetic and phenotypic features, allowing them to present a high capacity to survive and grow at different conditions, explaining its constant presence in food production and processing environments and in end products. These microorganisms are able to produce a wide variety of virulence factors, highlighting their relevance as safety indicators in foods; however, they are also able to produce bacteriocins, called enterocins, and to promote specific modifications in food during fermentation.
Enterococci are present in a variety of ripened cheeses, especially from the Mediterranean region, being responsible for specific aromas and flavors that determine the characteristics of these artisanal foods. Also, many Enterococcus species were characterized due to their probiotic potential, being included in commercial products to be consumed by humans and animals, aiming the promotion of health and well-being.
Despite being known for possessing virulence genes, many studies demonstrated the absence of expression of such genes, especially isolates obtained from food systems, leading to studies that investigate their real relevance as pathogenic microorganisms. So, this paradoxical role of enterococci in foods must be properly discussed by food microbiologists, which is the focus of this chapter. From Mouse To Man. Lactic acid bacteria LAB constitute a heterogeneous group of Gram-positive bacteria widely used in the food industry because of their generally regarded as safe GRAS status.
In this regard, LAB have been widely investigated and used as live vehicles for the production and delivery of heterologous proteins or cDNA of vaccinal, medical or technological interest because of its ease for protein secretion and purification. Here, we review the expression of heterologous protein and the various delivery systems developed to target heterologous proteins to specific cell locations cytoplasm, extracellular medium or cell wall , as well as the more recent research on LAB as DNA delivery vehicles and finale with the challenges and future trends to improve the existing strategies and develop new ones.
Bermudez-Humaran and Philippe Langella. Humans harbour a different microbiota depending on the tissue considered.
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Most of the microorganisms are contained in the gastro-intestinal tract GIT and this gut microbiota represents approximately cells that correspond to the highest bacterial density for any ecosystem. Our microbiota represents a huge diversity in term of species and functions. A healthy gut microbiota is composed of a well-balanced community of three permanent residents termed symbionts with beneficial effects , commensals no effect , and pathobionts potentially induce pathologies under certain situations , but no pathogens.
The term dysbiosis microbial imbalance has been related to many different kinds of pathologies although it is not clear whether the imbalance of such a microbiota is a cause or a consequence of the illness. Nowadays, the challenge of linking microbiota to human health and disease is being tackled by different research teams around the world with the aim to investigate the implication of potential beneficial bacteria that could be decreased in the studied microbiota of patients.
From this perspective, it could be interesting to use them as potential probiotics to try to resolve dysbioses. Hermien van Bokhorst-van de Veen, Peter A. Bron and Michiel Kleerebezem. This chapter describes stress responses of probiotic lactobacilli, in relation to gastrointestinal GI- tract robustness.
Handbook of Prebiotics and Probiotics Ingredients: Health Benefits and Food Applications
An overview is given of some newly developed tools to understand and improve stress responses of the model probiotic L. These include a relative simple GI-tract assay and the development of transcriptome-trait matching that associates a trait of interest e.
Furthermore, specific additives to the in situ delivery matrix may enhance the relative tolerance of specific bacterial strains to detrimental conditions they may encounter in different regions of the GI-tract.
Moreover, a methodology that allows the molecular quantification of single strains in a mixed bacterial population using engineered sequence-tags or naturally occurring discriminatory intergenic alleles in combination with next-generation sequencing offers another powerful tool for robustness evaluation. Finally, the stress responses of probiotic cultures in relation to improval of their GI persistence and some future directions for development and GI-tract research in the light of probiotic performance are discussed.
Marta C. Leite, Bryan Troxell, Jose M. Lactic acid bacteria LAB are important in food fermentations and in human health. Due to their physiological and ecological heterogeneity, they encounter a variety of stressors including acid, osmolality, heat, bile-salt, and oxygen. LAB are exposed to oxidative stress caused by the partially reduced reactive oxygen species ROS generated from endogenous sources as well as from the environment. Findings over the past fifty years have demonstrated that this group of organisms comprise a heterogeneous mixture of different genera, where some members of the group have the capacity to synthesis antioxidant enzymes like Mn-containing superoxide dismutase MnSOD , non-heme catalases i.
Furthermore, some members of the group can accumulate large intracellular concentrations of manganese to use in the detoxification of ROS. In this chapter, we discuss the natural defenses against ROS in LAB as well as the technological practices used in the food and nutraceutical industries to protect LAB from oxidative stress and loss of viability during processing and storage.
Over the past 2 or 3 decades we have learned a great deal about our gut microbiota.
It is well-established that the microbiota plays a role in just about any disease and disorder that human mankind suffers from. Primarily this is due to the interaction of the microbiota with the host at various levels: i modulation of the host immune system, which has effects far beyond the local effects in the gut and may reach up to the brain, and ii production of healthy or toxic microbial metabolites that also may have systemic effects, either directly or after co-metabolism by the host.
The composition, and hence the activity of the microbiota, is determined by food and medication. Certain food-components, such as prebiotics, fibers or polyphenols, may lead to production of health-promoting metabolites, while e. Antibiotics and other drugs may influence the composition and activity of the microbiota in such as way that the activity has deleterious effects on the host. This review discusses some of the functional aspects of the gut microbiota thought to be important for health of the host. This chapter will review recent insight in the functional role of the microbiota in health and disease.
The human gut microbiota is now recognised as an important contributor to host health and disease, with diet:microbe interactions playing critical roles in immune function, energy balance and even brain development and cognitive function. Importantly, these advances in the fields of physiology and nutrition have come at a time when methodologies for studying microbial communities are providing a comprehensive tool-kit of unparalleled resolution and breadth of coverage, allowing for the first time efficacious measurement of important ecological parameters within the gut microbiome.
These methods too allow us to measure both the metabolic potential and metabolic kinetic of the gut microbiota allowing researchers to shed new light on what was until very recently the black hole of microbiota ecological function within the gut. This chapter describes a collection of molecular genetic and metabolomic approaches used to study the human gut microbiota.
The human gut is comprised of diverse microbiota, which put substantial impact on various human diseases. The gut microbiota is linked to the maintaining gastrointestinal homeostasis and the association between metabolic and inflammatory diseases such as obesity, type 2 diabetes, low-grade chronic inflammation, and inflammatory bowel disease. Consequentially, the growing interest in gut microbiota has resulted in the development of functional foods such as probiotics and prebiotics, which have been reduce the risk of disease and improve host health. Recent advances in nucleotide sequencing technology widen the profile of the previously unknown microbial communities.
International collaborative projects such as the MetaHIT initiative and the Human Microbiome Project HMP revealed the diversity of the gut microbiota and their metabolic functions and interactions in the host using this new technique. Current advancement of these tools eases analysis of the massive datasets, yet challenges remain for a complete construction of the microbiome. Here we discuss the development of metagenomics along with the challenges and future perspectives for metagenomic studies to find new probiotics and prebiotics.
Prebiotics are non-digestible food ingredients that invigorate and boost proliferation of health-promoting bacteria in the gastro-intestinal tract, while inhibiting enteric pathogens.
Handbook of Prebiotics and Probiotics Ingredients - PDF Drive
The term prebiotics so far encompasses fermentable carbohydrates and oligosaccharides. Prebiotics were catapulted to prominence after their stimulatory role towards bifidobacteria was recognized. They are currently being implicated as sweetener, fat replacer, starter culture formulation, for bacteriocin induction as well as for gut health maintenance, laxative and colitis prevention. However, their functionality has now ramified to multiple significant domains.
The unconventional applications have been met with moderate to excellent success viz. The versatile usage of prebiotics has motivated intense research in this field. The exploration of new biological roles for established prebiotics, generation of new compounds from unconventional sources even extending beyond carbohydrates and up-grading of existing technology have been identified as promising.
This chapter presents in a nutshell, the known prebiotics and their conventional as well as evolving implications for enrichment of food, drugs, and cosmetics and use in the veterinary sector.
Prebiotics: Technological Aspects and Human Health. They are commonly described as short-chain carbohydrates containing between two and sixty monosaccharides, which are not digested by human or animal enzymes making them selectively fermented by specific beneficial colon bacteria.
Besides promoting the intestinal microbiota, they also prevent the incidence of gastrointestinal infections, modulate the immune system, increase the bioavailability of minerals, regulate metabolic disorders related to obesity and diabetes and decrease the risk of cancer.
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In addition to the functional characteristics, the use of prebiotics by the food industry has been prompted by their favorable technological aspects. New and Tailored Prebiotics: Established Applications. Shanthi G.