Bioengineered probiotics as a new hope for health and diseases: an overview of potential and prospects

Beyond conventional antibiotics approaches: Global perspectives on alternative therapeutics including herbal prevention, and proactive management strategies in bovine mastitis

Mastitis, an intramammary inflammation resulting from microbial infectious agents, continues to pose a significant challenge within the dairy sector, adversely affecting animal well-being and leading to substantial economic losses. These losses are attributed to decreased milk production, heightened culling rates, and the expenses related to diagnostics, veterinary care, medication, and labor. Moreover, additional costs emerge due to reduced forthcoming milk yields, compromised reproductive health, and increased susceptibility to various illnesses. Identifying the responsible agents is crucial for disease management and the implementation of antimicrobial treatments. Despite the prevalent use of antibiotic treatment, the pressing need for new therapeutic alternatives to combat bovine mastitis arises from limitations, including low cure rates, rising resistance, and the presence of antibiotic residues in milk. This review explores the potential application of herbal extracts and essential oils known for their antimicrobial properties as alternative options for managing pathogens in mastitis treatment. It examines various treatment methods and management strategies, particularly emphasizing the progress of herbal remedies and natural therapeutics in addressing mastitis, a significant concern in bovine populations and dairy herds.

Transcriptomic analysis reveals differential gene expression patterns of Lacticaseibacillus casei ATCC 393 in response to ultrasound stress

In recent years, there has been a growing interest in modulating the performance of probiotic, mainly Lactic Acid Bacteria (LAB), in the field of probiotic food. Attenuation, induced by sub-lethal stresses, delays the probiotic metabolism, and induces a metabolic shift as survival strategy. In this paper, RNA sequencing was used to uncover the transcriptional regulation in Lacticaseibacillus casei ATCC 393 after ultrasound-induced attenuation. Six (T) and 8 (ST) min of sonication induced a significant differential expression of 742 and 409 genes, respectively. We identified 198 up-regulated and 321 down-regulated genes in T, and similarly 321 up-regulated and 249 down-regulated in ST. These results revealed a strong defensive response at 6 min, followed by adaptation at 8 min. Ultrasound attenuation modified the expression of genes related to a series of crucial biomolecular processes including membrane transport, carbohydrate and purine metabolism, phage-related genes, and translation. Specifically, genes encoding PTS transporters and genes involved in the glycolytic pathway and pyruvate metabolism were up-regulated, indicating an increased need for energy supply, as also suggested by an increase in the transcription of purine biosynthetic genes. Instead, protein translation, a high-energy process, was inhibited with the down-regulation of ribosomal protein biosynthetic genes. Moreover, phage-related genes were down-regulated suggesting a tight transcriptional control on DNA structure. The observed phenomena highlight the cell need of ATP to cope with the multiple ultrasound stresses and the activation of processes to stabilize and preserve the DNA structure. Our work demonstrates that ultrasound has remarkable effects on the tested strain and elucidates the involvement of different pathways in its defensive stress-response and in the modification of its phenotype.

Plant-Derived Natural Products for the Treatment of Bacterial Infections

Bacterial infections are a significant public health concern, and the emergence of antibiotic-resistant bacteria (ARB) has become a major challenge for modern medicine. The overuse and misuse of antibiotics have contributed to the development of ARB, which has led to the need for alternative therapies. Plant-derived natural products (PNPs) have been extensively studied for their potential as alternative therapies for the treatment of bacterial infections. The diverse chemical compounds found in plants have shown significant antibacterial properties, making them a promising source of novel antibacterial agents. The use of PNPs as antibacterial agents is particularly appealing because they offer a relatively safe and cost-effective approach to the treatment of bacterial infections. This chapter aims to provide an overview of the current state of research on PNPs as antibacterial agents. It will cover the mechanisms of action of the main PNPs against bacterial pathogens and discuss their potential to be used as complementary therapies to combat ARB. This chapter will also highlight the most common screening methodologies to discover new PNPs and the challenges and future prospects in the development of these compounds as antibacterial agents.

Designer probiotics: Opening the new horizon in diagnosis and prevention of human diseases

Probiotic microorganisms have been used for therapeutic purposes for over a century, and recent advances in biotechnology and genetic engineering have opened up new possibilities for developing therapeutic approaches using indigenous probiotic microorganisms. Diseases are often related to metabolic and immunological factors, which play a critical role in their onset. With the help of advanced genetic tools, probiotics can be modified to produce or secrete important therapeutic peptides directly into mucosal sites, increasing their effectiveness. One potential approach to enhancing human health is through the use of designer probiotics, which possess immunogenic characteristics. These genetically engineered probiotics hold promise in providing novel therapeutic options. In addition to their immunogenic properties, designer probiotics can also be equipped with sensors and genetic circuits, enabling them to detect a range of diseases with remarkable precision. Such capabilities may significantly advance disease diagnosis and management. Furthermore, designer probiotics have the potential to be used in diagnostic applications, offering a less invasive and more cost-effective alternative to conventional diagnostic techniques. This review offers an overview of the different functional aspects of the designer probiotics and their effectiveness on different diseases and also, we have emphasized their limitations and future implications. A comprehensive understanding of these functional attributes may pave the way for new avenues of prevention and the development of effective therapies for a range of diseases.

The role of probiotics in tissue engineering and regenerative medicine

Tissue engineering and regenerative medicine (TERM) as an emerging field is a multidisciplinary science and combines basic sciences such as biomaterials science, biology, genetics and medical sciences to achieve functional TERM-based products to regenerate or replace damaged or diseased tissues or organs. Probiotics are useful microorganisms which have multiple effective functions on human health. They have some immunomodulatory and biocompatibility effects and improve wound healing. In this article, we describe the latest findings on probiotics and their pro-healing properties on various body systems that are useable in regenerative medicine. Therefore, this review presents a new perspective on the therapeutic potential of probiotics for TERM.

Recombinant Probiotic Preparations: Current State, Development and Application Prospects

The article is devoted to the latest achievements in the field of research, development, and implementation of various types of medicinal products based on recombinant probiotics. The benefits of probiotics, their modern use in medicine along with the most frequently used genera and species of probiotic microorganisms were highlighted. The medicinal and therapeutic activities of the studied probiotics were indicated. The review suggests various methods of creating recombinant probiotic microorganisms, including standard genetic engineering methods, as well as systems biology approaches and new methods of using the CRISPR-Cas system. The range of potential therapeutic applications of drugs based on recombinant probiotics was proposed. Special attention was paid to modern research on the creation of new, more effective recombinant probiotics that can be used for various therapeutic purposes. Considering the vast diversity of therapeutic applications of recombinant probiotics and ambiguous functions, their use for the potential treatment of various common human diseases (non-infectious and infectious diseases of the gastrointestinal tract, metabolic disorders, and allergic conditions) was investigated. The prospects for creating different types of vaccines based on recombinant probiotics together with the prospects for their implementation into medicine were considered. The possibilities of using recombinant probiotics in veterinary medicine, particularly for the prevention of domestic animal diseases, were reviewed. The prospects for the implementation of recombinant probiotics as vaccines and diagnostic tools for testing certain diseases as well as modeling the work of the human digestive system were highlighted. The risks of creation, application, including the issues related to the regulatory sphere regarding the use of new recombinant microorganisms, which can potentially enter the environment and cause unforeseen circumstances, were outlined.

A recombinant Bifidobacterium bifidum BGN4 strain expressing the streptococcal superoxide dismutase gene ameliorates inflammatory bowel disease

Background

Inflammatory bowel disease (IBD) is a gastrointestinal disease characterized by diarrhea, rectal bleeding, abdominal pain, and weight loss. Recombinant probiotics producing specific proteins with IBD therapeutic potential are currently considered novel drug substitutes. In this study, a Bifidobacterium bifidum BGN4-SK strain was designed to produce the antioxidant enzymes streptococcal superoxide dismutase (SOD) and lactobacillus catalase (CAT), and a B. bifidum BGN4-pBESIL10 strain was proposed to generate an anti-inflammatory cytokine, human interleukin (IL)-10. In vitro and in vivo efficacy of these genetically modified Bifidobacterium strains were evaluated for colitis amelioration.

Results

In a lipopolysaccharide (LPS)-stimulated HT-29 cell model, tumor necrosis factor (TNF)-α and IL-8 production was significantly suppressed in the B. bifidum BGN4-SK treatment, followed by B. bifidum BGN4-pBESIL10 treatment, when compared to the LPS-treated control. Synergistic effects on TNF-α suppression were also observed. In a dextran sodium sulphate (DSS)-induced colitis mouse model, B. bifidum BGN4-SK treatment significantly enhanced levels of antioxidant enzymes SOD, glutathione peroxidase (GSH-Px) and CAT, compared to the DSS-only group. B. bifidum BGN4-SK significantly ameliorated the symptoms of DSS-induced colitis, increased the expression of tight junction genes (claudin and ZO-1), and decreased pro-inflammatory cytokines IL-6, IL-1β and TNF-α.

Conclusions

These findings suggest that B. bifidum BGN4-SK ameliorated DSS-induced colitis by generating antioxidant enzymes, maintaining the epithelial barrier, and decreasing the production of pro-inflammatory cytokines. Although B. bifidum BGN4-pBESIL10 exerted anti-inflammatory effects in vitro, the enhancement of IL-10 production and alleviation of colitis were very limited.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01840-2.

Antibiotic Use in Livestock and Residues in Food-A Public Health Threat: A Review

The usage of antibiotics has been, and remains, a topic of utmost importance; on the one hand, for animal breeders, and on the other hand, for food safety. Although many countries have established strict rules for using antibiotics in animal husbandry for the food industry, their misuse and irregularities in compliance with withdrawal periods are still identified. In addition to animal-origin foods that may cause antibiotic residue problems, more and more non-animal-origin foods with this type of non-compliance are identified. In this context, we aim to summarize the available information regarding the presence of antibiotic residues in food products, obtained in various parts of the world, as well as the impact of consumption of food with antibiotic residues on consumer health. We also aim to present the methods of analysis that are currently used to determine antibiotic residues in food, as well as methods that are characterized by the speed of obtaining results or by the possibility of identifying very small amounts of residues.

Bioactive peptides produced by engineered probiotics and other food-grade bacteria: A review

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Synthetic biology improves probiotics therapeutic approaches.

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Engineering technologies contribute to design probiotics mechanisms of action.

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Edition of proteolytic systems induce the generation of specific bioactive peptides.

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Engineered probiotics should be evaluated as therapeutic agents in clinical trials.

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Therapeutical and technological uses of engineered probiotics are still controversial.

Synthetic biology is employed for the study and design of engineered microbes with new and improved therapeutic functions. The main advantage of synthetic biology is the selective genetic manipulation of living organisms with desirable beneficial effects such as probiotics. Engineering technologies have contributed to the edition of metabolic processes involved in the mechanisms of action of probiotics, such as the generation of bioactive peptides. Hence, current information related to bioactive peptides, produced by different engineering probiotics, with antimicrobial, antiviral, antidiabetic, and antihypertensive activities, as well as their potential use as functional ingredients, is discussed here. Besides, the effectiveness and safety aspects of these bioactive peptides were also described.

Lacticaseibacillus rhamnosus: A Suitable Candidate for the Construction of Novel Bioengineered Probiotic Strains for Targeted Pathogen Control

Probiotics, with their associated beneficial effects, have gained popularity for the control of foodborne pathogens. Various sources are explored with the intent to isolate novel robust probiotic strains with a broad range of health benefits due to, among other mechanisms, the production of an array of antimicrobial compounds. One of the shortcomings of these wild-type probiotics is their non-specificity. A pursuit to circumvent this limitation led to the advent of the field of pathobiotechnology. In this discipline, specific pathogen gene(s) are cloned and expressed into a given probiotic to yield a novel pathogen-specific strain. The resultant recombinant probiotic strain will exhibit enhanced species-specific inhibition of the pathogen and its associated infection. Such probiotics are also used as vehicles to deliver therapeutic agents. As fascinating as this approach is, coupled with the availability of numerous probiotics, it brings a challenge with regard to deciding which of the probiotics to use. Nonetheless, it is indisputable that an ideal candidate must fulfil the probiotic selection criteria. This review aims to show how Lacticaseibacillus rhamnosus, a clinically best-studied probiotic, presents as such a candidate. The objective is to spark researchers’ interest to conduct further probiotic-engineering studies using L. rhamnosus, with prospects for the successful development of novel probiotic strains with enhanced beneficial attributes.

Probiotic Releasing Angiotensin (1-7) in a Drosophila Model of Alzheimer's Disease Produces Sex-Specific Effects on Cognitive Function

BACKGROUND

While extensive research on the brain has failed to identify effective therapies, using probiotics to target the gut microbiome has shown therapeutic potential in Alzheimer's disease (AD). Genetically modified probiotics (GMP) are a promising strategy to deliver key therapeutic peptides with high efficacy and tissue specificity. Angiotensin (Ang)-(1-7) levels inversely correlate to AD severity, but its administration is challenging. Our group has successfully established a GMP-based method of Ang-(1-7) delivery.

OBJECTIVE

Since Drosophila represents an excellent model to study the effect of probiotics on complex disorders in a high throughput manner, we tested whether oral supplementation with Lactobacillus paracasei releasing Ang-(1-7) (LP-A) delays memory loss in a Drosophila AD model.

METHODS

Flies overexpressing the human amyloid-β protein precursor and its β-site cleaving enzyme in neurons were randomized to receive four 24-h doses of Lactobacillus paracasei alone (LP), LP-A or sucrose over 14 days. Memory was assessed via an aversive phototaxic suppression assay.

RESULTS

Optimal dilution,1:2, was determined based on palatability. LP-A improved memory in trained AD males but worsened cognition in AD females. LP-supplementation experiments confirmed that Ang-(1-7) conferred additional cognitive benefits in males and was responsible for the deleterious cognitive effects in females. Sex-specific differences in the levels of angiotensin peptides and differential activation of the kynurenine pathway of tryptophan metabolism in response to supplementation may underlie this male-only therapeutic response.

CONCLUSION

In summary, LP-A ameliorated the memory deficits of a Drosophila AD model, but effects were sex-specific. Dosage optimization may be required to address this differential response.

Insight of oral vaccines as an alternative approach to health and disease management: An innovative intuition and challenges

Vaccination is the most suitable and persuasive healthcare program for the prohibition of various deadly diseases. However, the higher production cost and purification strategies are out of reach for the developing nations. In this scenario, development of edible vaccine turns out to be the most promising alternative for remodeling the pharmaceutical industry with reduced production and purification costs. Generally, oral route of vaccination is mostly preferred due to its safety, compliance, low manufacturing cost and most importantly the ability to induce immunity in both systemic and mucosal sites. Genetically modified microorganisms and plants could efficiently be used as vehicles for edible vaccines. Edible vaccines are supposed to reduce the risk associated with traditional vaccines. Currently, oral vaccines are available in the market for several viral and bacterial diseases like cholera, hepatitis B, malaria, rabies etc. Herein, the review focuses on the breakthrough events in the area of edible vaccines associated with dietary microbes and plants for better control over diseases.

Gut-microbiota derived bioactive metabolites and their functions in host physiology

Every individual harbours a complex, diverse and mutualistic microbial flora in their intestine and over the time it became an integral part of the body, affecting a plethora of activities of the host. Interaction between host and gut-microbiota affects several aspects of host physiology. Gut-microbiota affects host metabolism by fermenting unabsorbed/undigested carbohydrates in the large intestine. Not only the metabolic functions, any disturbances in the composition of the gut-microbiota during first 2-3 years of life may impact on the brain development and later affects cognition and behaviour. Thus, gut-dysbiosis causes certain serious pathological conditions in the host including metabolic disorders, inflammatory bowel disease and mood alterations, etc. Microbial-metabolites in recent times have emerged as key mediators and are responsible for microbiota induced beneficial effects on host. This review provides an overview of the mechanism of microbial-metabolite production, their respective physiological functions and the impact of gut-microbiome in health and diseases. Metabolites from dietary fibres, aromatic amino acids such as tryptophan, primary bile acids and others are the potential substances and link microbiota to host physiology. Many of these metabolites act as signalling molecules to a number of cells types and also help in the secretion of hormones. Moreover, interaction of microbiota derived metabolites with their host, immunity boosting mechanisms, protection against pathogens and modulation of metabolism is also highlighted here. Understanding all these functional attributes of metabolites produced from gut-microbiota may lead to the opening of a new avenue for preventing and developing potent therapies against several diseases.

Evolutionary concepts in the functional biotics arena: a mini-review

Over the years, the attempts to elucidate the role of beneficial microorganisms in shaping human health are becoming fairly apparent. The functional impact conferred by such microbes is not only transmitted by viable cells or their metabolites but also through non-viable cells. Extensive research to unveil the protective action of such wonder bugs has resulted in categorizing the beneficial microflora and their bioactive metabolites into a variety of functional biotic concepts based on their intended applications in various forms. In the modern era, these are often termed as probiotics, prebiotics, synbiotics, postbiotics, next-generation probiotics, psychobiotics, oncobiotics, pharmabiotics, and metabiotics. Currently, the concept of traditional probiotics is being widened to include microbes beyond lactic acid bacteria. Indeed, this diversification has broadened the functional food portfolio from food to pharmaceuticals. In this context, the present review aims to summarize the existing biotic concepts and their differences thereof.

Angiotensin (1-7) Expressing Probiotic as a Potential Treatment for Dementia

Increasing life expectancies are unfortunately accompanied by increased prevalence of Alzheimer's disease (AD). Regrettably, there are no current therapeutic options capable of preventing or treating AD. We review here data indicating that AD is accompanied by gut dysbiosis and impaired renin angiotensin system (RAS) function. Therefore, we propose the potential utility of an intervention targeting both the gut microbiome and RAS as both are heavily involved in proper CNS function. One potential approach which our group is currently exploring is the use of genetically-modified probiotics (GMPs) to deliver therapeutic compounds. In this review, we specifically highlight the potential utility of utilizing a GMP to deliver Angiotensin (1-7), a beneficial component of the renin-angiotensin system with relevant functions in circulation as well as locally in the gut and brain.

Therapeutic Delivery of Ang(1-7) via Genetically Modified Probiotic: A Dosing Study

In recent years a number of beneficial health effects have been ascribed to the renin-angiotensin system (RAS) that extend beyond lowering blood pressure, primarily mediated via the angiotensin-converting enzyme-2 (ACE2)/angiotensin (1–7) or Ang(1–7)/MAS receptor axis. Moreover, once thought as merely a systemic effector, RAS components exist within tissues. The highest tissue concentrations of ACE2 mRNA are located in the gut making it an important target for altering RAS function. Indeed, genetically engineered recombinant probiotics are promising treatment strategies offering delivery of therapeutic proteins with precision. An Ang(1–7) secreting Lactobacillus paracasei (LP) or LP-A has been described for regulation of diabetes and hypertension; however, we are the first to the best of our knowledge to propose this paradigm as it relates to aging. In this Research Practice manuscript, we provide proof of concept for using this technology in a well-characterized rodent model of aging: the Fisher344 x Brown Norway Rat (F344BN). Our primary findings suggest that LP-A increases circulating levels of Ang(1–7) both acutely and chronically (after 8 or 28 treatment days) when administered 3× or 7×/week over 4 weeks. Our future preclinical studies will explore the impact of this treatment on gut and other age-sensitive distal tissues such as brain and muscle.

Futuristic Non-antibiotic Therapies to Combat Antibiotic Resistance: A Review

The looming problem of resistance to antibiotics in microorganisms is a global health concern. The drug-resistant microorganisms originating from anthropogenic sources and commercial livestock farming have posed serious environmental and health challenges. Antibiotic-resistant genes constituting the environmental "resistome" get transferred to human and veterinary pathogens. Hence, deciphering the origin, mechanism and extreme of transfer of these genetic factors into pathogens is extremely important to develop not only the therapeutic interventions to curtail the infections, but also the strategies to avert the menace of microbial drug-resistance. Clinicians, researchers and policymakers should jointly come up to develop the strategies to prevent superfluous exposure of pathogens to antibiotics in non-clinical settings. This article highlights the present scenario of increasing antimicrobial-resistance in pathogenic bacteria and the clinical importance of unconventional or non-antibiotic therapies to thwart the infectious pathogenic microorganisms.

Engineered Akkermansia muciniphila: A promising agent against diseases (Review)

Achieving a harmonious gut microbial ecosystem has been hypothesized to be a successful method for alleviating metabolic disorders. The administration of probiotics, such as Lactobacillus and Bifidobacteria, is a known traditional and safe pathway to regulate human commensal microbes. With advancements in genetic sequencing and genetic editing tools, more bacteria are able to function as engineered probiotics with multiple therapeutic properties. As one of the next-generation probiotic candidates, Akkermansia muciniphila (A. muciniphila) has been discovered to enhance the gut barrier function and moderate inflammatory responses, exhibit improved effects with pasteurization and display beneficial probiotic effects in individuals with obesity, type 2 diabetes, atherosclerosis and autism-related gastrointestinal disturbances. In view of this knowledge, the present review aimed to summarize the effects of A. muciniphila in the treatment of metabolic disorders and to discuss several mature recombination systems for the genetic modification of A. muciniphila. From gaining an enhanced understanding of its genetic background, ingested A. muciniphila is expected to be used in various applications, including as a diagnostic tool, and in the site-specific delivery of therapeutic drugs.

Antibiotics in Food Chain: The Consequences for Antibiotic Resistance

Antibiotics have been used as essential therapeutics for nearly 100 years and, increasingly, as a preventive agent in the agricultural and animal industry. Continuous use and misuse of antibiotics have provoked the development of antibiotic resistant bacteria that progressively increased mortality from multidrug-resistant bacterial infections, thereby posing a tremendous threat to public health. The goal of our review is to advance the understanding of mechanisms of dissemination and the development of antibiotic resistance genes in the context of nutrition and related clinical, agricultural, veterinary, and environmental settings. We conclude with an overview of alternative strategies, including probiotics, essential oils, vaccines, and antibodies, as primary or adjunct preventive antimicrobial measures or therapies against multidrug-resistant bacterial infections. The solution for antibiotic resistance will require comprehensive and incessant efforts of policymakers in agriculture along with the development of alternative therapeutics by experts in diverse fields of microbiology, biochemistry, clinical research, genetic, and computational engineering.

Probiotics-A complete oral healthcare package

Probiotics are living bacterial cells that have significant therapeutic potential for treating human infectious diseases. There is a huge market for probiotics in the pharmaceutical sector. They have been frequently used to treat the gastrointestinal diseases and improve gut immunity. In this review, the strains currently in use for manufacturing oral probiotic formulations are discussed. The review further recommends the use of probiotics for the control of various oral health disorders, like dental caries, periodontitis, gingivitis, halitosis, burning mouth syndrome, and oral cancer. Finally, this review also explores the use of various commercial probiotic products in maintaining oral health, their market values, and government acts and regulations that are relevant to the production and marketing of probiotics. Probiotics have tremendous therapeutic potential and more in-depth research must be done on these beneficial bacteria to make them one of the leading drugs in treating oral disorders.

The Gut Microbiome as a Therapeutic Target for Cognitive Impairment

Declining cognitive functions in older individuals have enormous emotional, clinical, and public health consequences. Thus, therapeutics for preserving function and keeping older adults living independently are imperative. Aging is associated dysbiosis, defined as a loss of number and diversity in gut microbiota, which has been linked with various aspects of cognitive functions. Therefore, the gut microbiome has the potential to be an important therapeutic target for symptoms of cognitive impairment. In this review, we summarize the current literature regarding the potential for gut-targeted therapeutic strategies for prevention/treatment of the symptoms of cognitive impairment. Specifically, we discuss four primary therapeutic strategies: wild-type and genetically modified probiotics, fecal microbiota transplantation, physical exercise, and high-fiber diets and specifically link these therapies to reducing inflammation. These strategies may hold promise as treatment paradigm symptoms related to cognitive impairment.

Angiotensin (1-7) delivered orally via probiotic, but not subcutaneously, benefits the gut-brain axis in older rats

To (1) investigate the efficacy of multiple doses of an orally delivered probiotic bacteria Lactobacillus paracasei (LP) modified to express angiotensin (1-7) (LP-A) in altering physiologic parameters relevant to the gut-brain axis in older rats and to (2) compare this strategy with subcutaneous delivery of synthetic Ang(1-7) peptide on circulating Ang(1-7) concentrations and these gut-brain axis parameters. Male 24-month-old F344BN rats received oral gavage of LP-A, or subcutaneous injection of Ang(1-7) for 0×, 1×, 3×, or 7×/week over 4 weeks. Circulating RAS analytes, inflammatory cytokines, and tryptophan and its downstream metabolites were measured by ELISA, electrochemiluminescence, and LC-MS respectively. Microbiome taxonomic analysis of fecal samples was performed via 16S-based PCR. Inflammatory and tryptophan-related mRNA expression was measured in colon and pre-frontal cortex. All dosing regimens of LP-A induced beneficial changes in fecal microbiome including overall microbiota community structure and α-diversity, while the 3×/week also significantly increased expression of the anti-inflammatory species Akkermansia muciniphila. The 3×/week also increased serum serotonin and the neuroprotective analyte 2-picolinic acid. In the colon, LP-A increased quinolinate phosphoribosyltransferase expression (1×/week) and increased kynurenine aminotransferase II (1× and 3×/week) mRNA expression. LP-A also significantly reduced neuro-inflammatory gene expression in the pre-frontal cortex (3×/week: COX2, IL-1β, and TNFα; 7×/week: COX2 and IL-1β). Subcutaneous delivery of Ang(1-7) increased circulating Ang(1-7) and reduced angiotensin II, but most gut-brain parameters were unchanged in response. Oral-but not subcutaneous-Ang(1-7) altered physiologic parameters related to gut-brain axis, with the most effects observed in 3×/week oral dosing regimen in older rats.

The Inoculation of Probiotics In Vivo Is a Challenge: Strategies to Improve Their Survival, to Avoid Unpleasant Changes, or to Enhance Their Performances in Beverages

The inoculation of probiotics in beverages (probiotication) requires special technologies, as probiotic microorganisms can experience stress during food processing (acid, cold, drying, starvation, oxidative, and osmotic stresses) and gastrointestinal transit. Survival to harsh conditions is an essential prerequisite for probiotic bacteria before reaching the target site where they can exert their health promoting effects, but several probiotics show a poor resistance to technological processes, limiting their use to a restricted number of food products. Therefore, this paper offers a short overview of the ways to improve bacterial resistance: by inducing a phenotypic modification (adaptation) or by surrounding bacteria through a physical protection (microencapsulation). A second topic briefly addressed is genetic manipulation, while the last section addresses the control of metabolism by attenuation through physical treatments to design new kinds of food.

Internalin AB-expressing recombinant Lactobacillus casei protects Caco-2 cells from Listeria monocytogenes-induced damages under simulated intestinal conditions

Background

Listeria monocytogenes is an intracellular foodborne pathogen that employs a number of strategies to survive challenging gastrointestinal conditions. It proliferates in the gut and subsequently causes listeriosis in high-risk individuals. Therefore, inhibition of its adherence to the intestinal receptors is crucial in controlling its infection. In this study, the effect of our previously developed recombinant Lactobacillus casei strain expressing invasion protein, Internalin AB of L. monocytogenes (Lbc^InlAB) on epithelial infection processes of the latter under simulated intestinal conditions was investigated.

Materials and methods

The confluent Caco-2 cell monolayer was pre-exposed to different L. casei strains at a multiplicity of exposure (MOE) of 10 for various periods before infection with L. monocytogenes at a multiplicity of infection (MOI) of 10 under simulated intestinal conditions. Subsequently, L. monocytogenes adhesion, invasion, and translocation, cytotoxicity and impact on tight junction integrity of the Caco-2 cells were analyzed.

Results

Under the simulated gastrointestinal condition, Lbc^InlAB showed a significant increase (p<0.0001) in adherence to, invasion and translocation through the Caco-2 cells when compared with the wild type strain. Although Lbc^InlAB strain exhibited enhanced inhibition of L. monocytogenes, it was not able to displace L. monocytogenes cells already attached to the monolayer. Additionally, pre-exposure to Lbc^InlAB reduced L. monocytogenes-mediated cytotoxicity and protected the tight junction barrier function.

Conclusion

The recombinant L. casei expressing InlAB shows potential for use as a prophylactic intervention strategy for targeted control of L. monocytogenes during the intestinal phase of infection.

AllergoOncology: Microbiota in allergy and cancer-A European Academy for Allergy and Clinical Immunology position paper

The microbiota can play important roles in the development of human immunity and the establishment of immune homeostasis. Lifestyle factors including diet, hygiene, and exposure to viruses or bacteria, and medical interventions with antibiotics or anti-ulcer medications, regulate phylogenetic variability and the quality of cross talk between innate and adaptive immune cells via mucosal and skin epithelia. More recently, microbiota and their composition have been linked to protective effects for health. Imbalance, however, has been linked to immune-related diseases such as allergy and cancer, characterized by impaired, or exaggerated immune tolerance, respectively. In this AllergoOncology position paper, we focus on the increasing evidence defining the microbiota composition as a key determinant of immunity and immune tolerance, linked to the risk for the development of allergic and malignant diseases. We discuss novel insights into the role of microbiota in disease and patient responses to treatments in cancer and in allergy. These may highlight opportunities to improve patient outcomes with medical interventions supported through a restored microbiome.

Targeting ideal oral vaccine vectors based on probiotics: a systematical view

Probiotics have great potential to be engineered into oral vaccine delivery systems, which can facilitate elicitation of mucosal immunity without latent risks of pathogenicity. Combined with the progressive understanding of probiotics and the mucosal immune system as well as the advanced biotechniques of genetic engineering, the development of promising oral vaccine vectors based on probiotics is available while complicated and demanding. Therefore, a systematical view on the design of practical probiotic vectors is necessary, which will help to logically analyze and resolve the problems that might be neglected during our exploration. Here, we attempt to systematically summarize several fundamental issues vital to the effectiveness of the vector of probiotics, including the stability of the engineered vectors, the optimization of antigen expression, the improvement of colonization, and the enhancement of immunoreactivity. We also compared the existent strategies and some developing ones, attempting to figure out an optimal strategy that might deserve to be referred in the future development of oral vaccine vectors based on probiotics.

A New Bifidobacteria Expression SysTem (BEST) to Produce and Deliver Interleukin-10 in Bifidobacterium bifidum

In the last years there has been a growing interest in the use of genetically modified bacteria to deliver molecules of therapeutic interest at mucosal surfaces. Due to the well-recognized probiotic properties of some strains, bifidobacteria represent excellent candidates for the development of live vehicles to produce and deliver heterologous proteins at mucosal surfaces. However, very few studies have considered this genus because of its complexity to be genetically manipulated. In this work, we report the development of a new Bifidobacteria Expression SysTem (BEST) allowing the production of heterologous proteins in Bifidobacterium bifidum. This system is based on: i) the broad host range plasmid pWV01, ii) a stress-inducible promoter, and iii) two different signal peptides (SPs) one issued from Lactococcus lactis (SP_Exp4) and issued from Bifidobacterium longum (SP_BL1181). The functionality of BEST system was validated by cloning murine interleukin-10 (IL-10) and establishing the resulting plasmids (i.e., pBEST_Exp4:IL-10 and pBEST_BL1181:IL-10) in the strain of B. bifidum BS42. We then demonstrated in vitro that recombinant B. bifidum BS42 harboring pBEST_BL1181:IL-10 plasmid efficiently secreted IL-10 and that this secretion was significantly higher (sevenfold) than its counterpart B. bifidum BS42 harboring pBEST_Exp4:IL-10 plasmid. Finally, we validated in vivo that recombinant B. bifidum strains producing IL-10 using BEST system efficiently delivered this cytokine at mucosal surfaces and exhibit beneficial effects in a murine model of low-grade intestinal inflammation.

Nanomedicine in cancer stem cell therapy: from fringe to forefront

Nanomedicine is the spin-off of modern medicine and nanotechnology and aims to prevent and treat diseases using nanoscale materials such as biocompatible nanoparticles and nanorobots. Targeted cellular and tissue-specific clinical applications with maximal therapeutic effects and insignificant side effects could be achieved by the pursuit of nanotechnology in medicine and healthcare regimen. The majority of conventional cancer therapies eliminate the cells of the tumor but not the cancer stem cells (CSCs). Conversely, the use of nanotechnology in CSC-based therapies is an emerging field of biomedical sciences. This article summarizes the recent trends and application of nanomedicine especially in CSC therapy along with its limitations.

Probiotics: A Promising Role in Dental Health

Probiotics have a role in maintaining oral health through interaction with oral microbiome, thus contributing to healthy microbial equilibrium. The nature and composition of any individual microbiome impacts the general health, being a major contributor to oral health. The emergence of drug resistance and the side effects of available antimicrobials have restricted their use in an array of prophylactic options. Indeed, some new strategies to prevent oral diseases are based on manipulating oral microbiota, which is provided by probiotics. Currently, no sufficient substantial evidence exists to support the use of probiotics to prevent, treat or manage oral cavity diseases. At present, probiotic use did not cause adverse effects or increased risks of caries or periodontal diseases. This implicates no strong evidence against treatment using probiotics. In this review, we try to explore the use of probiotics in prevention, treatment and management of some oral cavity diseases and the possibilities of developing designer probiotics for the next generation of oral and throat complimentary healthcare.

Designer Probiotics: Paving the Way to Living Therapeutics

Enhancing the functional repertoire of probiotics is a promising approach to cope with the inexorable rise of antibiotic-resistant pathogens and the rather slow development of new antibiotics. Probiotics that deliver novel therapeutics efficiently and with site specificity are emerging living therapeutics that may transform existing paradigms of disease diagnosis and prevention.

(Dis)Trust your gut: the gut microbiome in age-related inflammation, health, and disease

Chronic inflammation represents one of the most consistent biologic features of aging. However, the precise etiology of persistent low-grade increases in inflammation remains unclear. Recent evidence suggests that the gut microbiome may play a key role in age-related inflammation. Indeed, several studies have indicated that older adults display an altered composition of the gut microbiota, and early evidence indicates that this dysbiosis is associated with the presence of several key circulating inflammatory analytes. The present review summarizes knowledge on age-related inflammation and discusses how potential relationships with gut dysbiosis may lead to novel treatment strategies in the future."The pattern of disease is an expression of the response of man to his total environment (physical, biological, and social); this response is, therefore, determined by anything that affects man himself or his environment." - Rene Dubos, 1961.

Probiotic engineering: towards development of robust probiotic strains with enhanced functional properties and for targeted control of enteric pathogens

There is a growing concern about the increase in human morbidity and mortality caused by foodborne pathogens. Antibiotics were and still are used as the first line of defense against these pathogens, but an increase in the development of bacterial antibiotic resistance has led to a need for alternative effective interventions. Probiotics are used as dietary supplements to promote gut health and for prevention or alleviation of enteric infections. They are currently used as generics, thus making them non-specific for different pathogens. A good understanding of the infection cycle of the foodborne pathogens as well as the virulence factors involved in causing an infection can offer an alternative treatment with specificity. This specificity is attained through the bioengineering of probiotics, a process by which the specific gene of a pathogen is incorporated into the probiotic. Such a process will subsequently result in the inhibition of the pathogen and hence its infection. Recombinant probiotics offer an alternative novel therapeutic approach in the treatment of foodborne infections. This review article focuses on various strategies of bioengineered probiotics, their successes, failures and potential future prospects for their applications.

Gut microbiota: A player in aging and a target for anti-aging intervention

Aging-associated alterations in composition, diversity and functional features of intestinal microbiota are well-described in the modern literature. They are suggested to be caused by an age-related decline in immune system functioning (immunosenescence) and a low-grade chronic inflammation (inflammaging), which accompany many aging-associated pathologies. The microbiota-targeted dietary and probiotic interventions have been shown to favorably affect the host health and aging by an enhancement of antioxidant activity, improving immune homeostasis, suppression of chronic inflammation, regulation of fat deposition and metabolism and prevention of insulin resistance. Recently, a high effectiveness and safety of novel therapeutic application such as fecal microbiota transplantation in the prevention and treatment of age-related pathological conditions including atherosclerosis, type 2 diabetes and Parkinson's disease has been demonstrated. In this review, recent research findings are summarized on the role of gut micribiota in aging processes with emphasis on therapeutic potential of microbiome-targeted interventions in anti-aging medicine.

In silico functional elucidation of uncharacterized proteins of Chlamydia abortus strain LLG

AIM

This study reports structural modeling, molecular dynamics profiling of hypothetical proteins in Chlamydia abortus genome database.

METHODOLOGY

The hypothetical protein sequences were extracted from C. abortus LLG Genome Database for functional elucidation using in silico methods.

RESULTS

Fifty-one proteins with their roles in defense, binding and transporting other biomolecules were unraveled. Forty-five proteins were found to be nonhomologous to proteins present in hosts infected by C. abortus. Of these, 31 proteins were related to virulence. The structural modeling of two proteins, first, WP_006344020.1 (phosphorylase) and second, WP_006344325.1 (chlamydial protease/proteasome-like activity factor) were accomplished. The conserved active sites necessary for the catalytic function were analyzed.

CONCLUSION

The finally concluded proteins are envisioned as possible targets for developing drugs to curtail chlamydial infections, however, and should be validated by molecular biological methods.