Live biotherapeutic products: the importance of a defined regulatory framework

Sensitive delivery systems and novel encapsulation technologies for live biotherapeutic products and probiotics

Live biotherapeutic product (LBP), a type of biological product, holds promise for the prevention or treatment of metabolic disease and pathogenic infection. Probiotics are live microorganisms that improve the intestinal microbial balance and beneficially affect the health of the host when ingested in sufficient numbers. These biological products possess the advantages of inhibition of pathogens, degradation of toxins, and modulation of immunity. The application of LBP and probiotic delivery systems has attracted great interest to researchers. The initial used technologies for LBP and probiotic encapsulation are traditional capsules and microcapsules. However, the stability and targeted delivery capability require further improved. The specific sensitive materials can greatly improve the delivery efficiency of LBPs and probiotics. The specific sensitive delivery systems show advantages over traditional ones due to their better properties of biocompatibility, biodegradability, innocuousness, and stability. Moreover, some new technologies, including layer-by-layer encapsulation, polyelectrolyte complexation, and electrohydrodynamic technology, show great potential in LBP and probiotic delivery. In this review, novel delivery systems and new technologies of LBPs and probiotics were presented, and the challenges and prospects were explored in specific sensitive materials for LBP and probiotic delivery.

Probiotics are beneficial for liver cirrhosis: a systematic review and meta-analysis of randomized control trials

Introduction

Gut dysbiosis may play a pivotal role in the pathogenesis of cirrhosis and the severity of complications. Numerous studies have investigated the probiotics as treatments for cirrhosis. However, there is still a lack of definitive evidence confirming the beneficial effects of probiotics on cirrhosis.

Methods

Databases including PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched for randomized controlled trials that compared the effects of probiotic intervention and control treatments, including placebo, no treatment, and active control, on cirrhosis, published from inception to February 2024. Outcomes included hepatic encephalopathy (HE) reversal, safety and tolerability of probiotics, liver function, quality of life, and other cirrhotic-related outcomes. A meta-analysis was conducted to synthesize evidence.

Results

Thirty studies were included. The quantitative synthesis results showed that compared with the control group, probiotics significantly reverse minimal hepatic encephalopathy (MHE) (risk ratio [RR] 1.54, 95% confidence interval [CI] 1.03 to 2.32) and improve HE (RR 1.94, 95% CI 1.24 to 3.06). Additionally, probiotics demonstrated higher safety and tolerability by causing a lower incidence of serious adverse events (RR 0.71, 95% CI 0.58 to 0.87). Probiotics could potentially improve liver function by reducing the Model for End-Stage Liver Disease (MELD) scores (standardized mean difference [SMD] -0.57, 95% CI -0.85 to -0.30), and displayed favorable changes in quality of life (SMD 0.51, 95% CI 0.27 to 0.75) and gut flora (SMD 1.67, 95% CI 1.28 to 2.06).

Conclusion

This systematic review and meta-analysis offers compelling evidence that probiotics are beneficial for cirrhosis by demonstrating reversal of HE, potential for liver function improvements, enhancements in quality of life, and regulation of gut dysbiosis. Furthermore, the apparent safety profile suggests that probiotics are a promising intervention for treating cirrhosis.

Clinical trial registration number

CRD42023478380.

Past, present, and future of microbiome-based therapies

Technological advances in studying the human microbiome in depth have enabled the identification of microbial signatures associated with health and disease. This confirms the crucial role of microbiota in maintaining homeostasis and the host health status. Nowadays, there are several ways to modulate the microbiota composition to effectively improve host health; therefore, the development of therapeutic treatments based on the gut microbiota is experiencing rapid growth. In this review, we summarize the influence of the gut microbiota on the development of infectious disease and cancer, which are two of the main targets of microbiome-based therapies currently being developed. We analyze the two-way interaction between the gut microbiota and traditional drugs in order to emphasize the influence of gut microbial composition on drug effectivity and treatment response. We explore the different strategies currently available for modulating this ecosystem to our benefit, ranging from 1st generation intervention strategies to more complex 2nd generation microbiome-based therapies and their regulatory framework. Lastly, we finish with a quick overview of what we believe is the future of these strategies, that is 3rd generation microbiome-based therapies developed with the use of artificial intelligence (AI) algorithms.

Can the Evidence-Based Use of Probiotics (Notably Saccharomyces boulardii CNCM I-745 and Lactobacillus rhamnosus GG) Mitigate the Clinical Effects of Antibiotic-Associated Dysbiosis?

Dysbiosis corresponds to the disruption of a formerly stable, functionally complete microbiota. In the gut, this imbalance can lead to adverse health outcomes in both the short and long terms, with a potential increase in the lifetime risks of various noncommunicable diseases and disorders such as atopy (like asthma), inflammatory bowel disease, neurological disorders, and even behavioural and psychological disorders. Although antibiotics are highly effective in reducing morbidity and mortality in infectious diseases, antibiotic-associated diarrhoea is a common, non-negligible clinical sign of gut dysbiosis (and the only visible one). Re-establishment of a normal (functional) gut microbiota is promoted by completion of the clinically indicated course of antibiotics, the removal of any other perturbing external factors, the passage of time (i.e. recovery through the microbiota's natural resilience), appropriate nutritional support, and-in selected cases-the addition of probiotics. Systematic reviews and meta-analyses of clinical trials have confirmed the strain-specific efficacy of some probiotics (notably the yeast Saccharomyces boulardii CNCM I-745 and the bacterium Lactobacillus rhamnosus GG) in the treatment and/or prevention of antibiotic-associated diarrhoea in children and in adults. Unusually for a probiotic, S. boulardii is a eukaryote and is not therefore directly affected by antibiotics-making it suitable for administration in cases of antibiotic-associated diarrhoea. A robust body of evidence from clinical trials and meta-analyses shows that the timely administration of an adequately dosed probiotic (upon initiation of antibiotic treatment or within 48 h) can help to prevent or resolve the consequences of antibiotic-associated dysbiosis (such as diarrhoea) and promote the resilience of the gut microbiota and a return to the pre-antibiotic state. A focus on the prescription of evidence-based, adequately dosed probiotics should help to limit unjustified and potentially ineffective self-medication.

Profiling of endogenous metabolites and changes in intestinal microbiota distribution after GEN-001 (Lactococcus lactis) administration

This study aimed to identify metabolic biomarkers and investigate changes in intestinal microbiota in the feces of healthy participants following administration of Lactococcus lactis GEN-001. GEN-001 is a single-strain L. lactis strain isolated from the gut of a healthy human volunteer. The study was conducted as a parallel, randomized, phase 1, open design trial. Twenty healthy Korean males were divided into five groups according to the GEN-001 dosage and dietary control. Groups A, B, C, and D1 received 1, 3, 6, and 9 GEN-001 capsules (1 × 1011 colony forming units), respectively, without dietary adjustment, whereas group D2 received 9 GEN-001 capsules with dietary adjustment. All groups received a single dose. Fecal samples were collected 2 days before GEN-001 administration to 7 days after for untargeted metabolomics and gut microbial metagenomic analyses; blood samples were collected simultaneously for immunogenicity analysis. Levels of phenylalanine, tyrosine, cholic acid, deoxycholic acid, and tryptophan were significantly increased at 5-6 days after GEN-001 administration when compared with predose levels. Compared with predose, the relative abundance (%) of Parabacteroides and Alistipes significantly decreased, whereas that of Lactobacillus and Lactococcus increased; Lactobacillus and tryptophan levels were negatively correlated. A single administration of GEN-001 shifted the gut microbiota in healthy volunteers to a more balanced state as evidenced by an increased abundance of beneficial bacteria, including Lactobacillus, and higher levels of the metabolites that have immunogenic properties.

Synthetic Communities of Gut Microbes for Basic Research and Translational Approaches in Animal Health and Nutrition

Microbes and animals have a symbiotic relationship that greatly influences nutrient uptake and animal health. This relationship can be studied using selections of microbes termed synthetic communities, or SynComs. SynComs are used in many different animal hosts, including agricultural animals, to investigate microbial interactions with nutrients and how these affect animal health. The most common host focuses for SynComs are currently mouse and human, from basic mechanistic research through to translational disease models and live biotherapeutic products (LBPs) as treatments. We discuss SynComs used in basic research models and findings that relate to human and animal health and nutrition. Translational use cases of SynComs are discussed, followed by LBPs, especially within the context of agriculture. SynComs still face challenges, such as standardization for reproducibility and contamination risks. However, the future of SynComs is hopeful, especially in the areas of genome-guided SynCom design and custom SynCom-based treatments.

Positioning the preventive potential of microbiome treatments for cystic fibrosis in the context of current therapies

Antibiotics and cystic fibrosis transmembrane conductance regulator (CFTR) modulators play a pivotal role in cystic fibrosis (CF) treatment, but both have limitations. Antibiotics are linked to antibiotic resistance and disruption of the airway microbiome, while CFTR modulators are not widely accessible, and structural lung damage and pathogen overgrowth still occur. Complementary strategies that can beneficially modulate the airway microbiome in a preventive way are highly needed. This could be mediated via oral probiotics, which have shown some improvement of lung function and reduction of airway infections and exacerbations, as a cost-effective approach. However, recent data suggest that specific and locally administered probiotics in the respiratory tract might be a more targeted approach to prevent pathogen outgrowth in the lower airways. This review aims to summarize the current knowledge on the CF airway microbiome and possibilities of microbiome treatments to prevent bacterial and/or viral infections and position them in the context of current CF therapies.

Exploitation of microbial activities at low pH to enhance planetary health

Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is, however, under-recognized that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing, and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization, or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical-chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective.

Tunable control of B. infantis abundance and gut metabolites by co-administration of human milk oligosaccharides

Precision engineering of the gut microbiome holds promise as an effective therapeutic approach for diseases associated with a disruption in this microbial community. Engrafting a live biotherapeutic product (LBP) in a predictable, controllable manner is key to the consistent success of this approach and has remained a challenge for most LBPs under development. We recently demonstrated high-level engraftment of Bifidobacterium longum subsp. infantis (B. infantis) in adults when co-dosed with a specific prebiotic, human milk oligosaccharides (HMO). Here, we present a cellular kinetic-pharmacodynamic approach, analogous to pharmacokinetic-pharmacodynamic-based analyses of small molecule- and biologic-based drugs, to establish how HMO controls expansion, abundance, and metabolic output of B. infantis in a human microbiota-based model in gnotobiotic mice. Our data demonstrate that the HMO dose controls steady-state abundance of B. infantis in the microbiome, and that B. infantis together with HMO impacts gut metabolite levels in a targeted, HMO-dependent manner. We also found that HMO creates a privileged niche for B. infantis expansion across a 5-log range of bacterial inocula. These results demonstrate remarkable control of both B. infantis levels and the microbiome community metabolic outputs using this synbiotic approach, and pave the way for precision engineering of desirable microbes and metabolites to treat a range of diseases.

Current Regulatory Issues for the Use of Probiotics

The chapter provides an overview of the current regulatory challenges surrounding the use of probiotics. It explores the global regulatory landscape, noting the need for uniform regulations across various regions. It emphasizes that these inconsistencies pose challenges for consumers, healthcare professionals, and industry stakeholders. Furthermore, the chapter highlights the ongoing efforts at the Codex Alimentarius to establish harmonized probiotic guidelines. The chapter also discusses labeling regulations, stressing the need for more accurate and comprehensive information on probiotic products to aid in evidence-based decision-making. Finally, it addresses safety concerns, particularly for vulnerable populations like children, and calls for a multi-layered approach to safety assessments. The chapter concludes by advocating harmonizing regulations and guidelines to facilitate probiotics' safer and more effective use.

Control points for design of taxonomic composition in synthetic human gut communities

Microbial communities offer vast potential across numerous sectors but remain challenging to systematically control. We develop a two-stage approach to guide the taxonomic composition of synthetic microbiomes by precisely manipulating media components and initial species abundances. By combining high-throughput experiments and computational modeling, we demonstrate the ability to predict and design the diversity of a 10-member synthetic human gut community. We reveal that critical environmental factors governing monoculture growth can be leveraged to steer microbial communities to desired states. Furthermore, systematically varied initial abundances drive variation in community assembly and enable inference of pairwise inter-species interactions via a dynamic ecological model. These interactions are overall consistent with conditioned media experiments, demonstrating that specific perturbations to a high-richness community can provide rich information for building dynamic ecological models. This model is subsequently used to design low-richness communities that display low or high temporal taxonomic variability over an extended period. A record of this paper's transparent peer review process is included in the supplemental information.

Comparing technology and regulatory landscape of probiotics as food, dietary supplements and live biotherapeutics

Application of beneficial microorganisms as probiotics targets a broad range of intended uses, from maintaining health and supporting normal bodily functions to curing and preventing diseases. Currently, three main regulatory fields of probiotic products can be defined depending on their intended use: the more similar probiotic foods and probiotic dietary supplements, and live biotherapeutic products. However, it is not always straightforward to classify a probiotic product into one of these categories. The regulatory nuances of developing, manufacturing, investigating and applying each category of probiotic products are not universal, and not always apparent to those unfamiliar with the various global probiotic regulatory guidelines. Various global markets can be significantly different regarding legislation, possible claims, market value and quality requirements for the development and commercialization of probiotic products. Furthermore, different probiotic product categories are also linked with variable costs at different stages of product development. This review outlines the current landscape comparing probiotic foods, probiotic dietary supplements, and live biotherapeutics as probiotic products from a regulatory lens, focusing on product development, manufacturing and production, and clinical research agenda. The aim is to inform and promote a better understanding among stakeholders by outlining the expectations and performance for each probiotic product category, depending on their intended use and targeted geographical region.

Gut microbiota and immunotherapy of renal cell carcinoma

The gut microbiome has recently been proposed as a key player in cancer development and progression. Several studies have reported that the composition of the gut microbiome plays a role in the response to immune checkpoint inhibitors (ICIs). The gut microbiome modulation has been investigated as a potential therapeutic strategy for cancer, mainly in patients undergoing therapy with ICIs. In particular, modulation through probiotics, FMT or other microbiome-related approaches have proven effective to improve the response to ICIs. In this review, we examine the role of the gut microbiome in enhancing clinical responses to ICIs in the treatment of renal cancer.

Clinical research with probiotics as an indicator of global valorization since the year 2000

Probiotics are becoming increasingly popular due to their potential health benefits. With this rise in popularity and demand as indicated by ever-growing market prospects, it seems evident that innovation and valorization are on the rise as well. However, an increasing body of literature shows that innovation is stagnating, which may be detrimental to the exploitation of the benefits of probiotics, for example the development of alternative therapies to manage the increasing prevalence of metabolic and autoimmune disorders. To this end, this study investigated global clinical trials that have been executed since the year 2000 as a first indicator of the status of probiotic valorization. The cumulative number of clinical trials has indeed increased significantly from 0 at the start of the century up to 2,517 registered trials in 2023. However, in Asia, Europe, and North America, the continents with the highest numbers of clinical trials, stagnating or declining trends have been found. In these locations, most clinical trials were funded by non-industry sponsors and targeting probiotic supplements or undefined products. Considering the overall stagnation in clinical trials and viewing these trends in the context of developments in local markets and regulations, the global valorization of probiotics appears to slow down. This could impact the transition from academic research to the development of products that are beneficial and accessible for consumers, either to maintain a healthy lifestyle or to treat medical conditions.

Recent advances in single-cell engineered live biotherapeutic products research for skin repair and disease treatment

The human microbiome has emerged as a key player in maintaining skin health, and dysbiosis has been linked to various skin disorders. Amidst growing concerns regarding the side effects of antibiotic treatments, the potential of live biotherapeutic products (LBPs) in restoring a healthy microbiome has garnered significant attention. This review aims to evaluate the current state of the art of the genetically or metabolically engineered LBPs, termed single-cell engineered LBPs (eLBPs), for skin repair and disease treatment. While some studies demonstrate promising outcomes, the translation of eLBPs into clinical applications remains a significant hurdle. Substantial concerns arise regarding the practical implementation and scalability of eLBPs, despite the evident potential they hold in targeting specific cells and delivering therapeutic agents. This review underscores the need for further research, robust clinical trials, and the exploration of current advances in eLBP-based bioengineered bacterial chassis and new outlooks to substantiate the viability and effectiveness of eLBPs as a transformative approach in skin repair and disease intervention.

Gut microbiota research nexus: One Health relationship between human, animal, and environmental resistomes

The emergence and rapid spread of antimicrobial resistance is of global public health concern. The gut microbiota harboring diverse commensal and opportunistic bacteria that can acquire resistance via horizontal and vertical gene transfers is considered an important reservoir and sink of antibiotic resistance genes (ARGs). In this review, we describe the reservoirs of gut ARGs and their dynamics in both animals and humans, use the One Health perspective to track the transmission of ARG-containing bacteria between humans, animals, and the environment, and assess the impact of antimicrobial resistance on human health and socioeconomic development. The gut resistome can evolve in an environment subject to various selective pressures, including antibiotic administration and environmental and lifestyle factors (e.g., diet, age, gender, and living conditions), and interventions through probiotics. Strategies to reduce the abundance of clinically relevant antibiotic-resistant bacteria and their resistance determinants in various environmental niches are needed to ensure the mitigation of acquired antibiotic resistance. With the help of effective measures taken at the national, local, personal, and intestinal management, it will also result in preventing or minimizing the spread of infectious diseases. This review aims to improve our understanding of the correlations between intestinal microbiota and antimicrobial resistance and provide a basis for the development of management strategies to mitigate the antimicrobial resistance crisis.

Quality Management of Probiotics: Ensuring Safety and Maximizing Health Benefits

Consumption of probiotics, which are beneficial live microorganisms, has received a lot of attention because of their potential to improve health and wellness. Robust quality control measures are necessary to ensure the safety of probiotics and maximize their health effects. This review delves into the topic of quality management in probiotics, highlighting the significance of sticking to strict guidelines from manufacture to storage to distribution. Probiotic quality standards, Good Manufacturing Practices (GMP) implementation, quality control and testing techniques, and documentation and traceability systems are all discussed in detail. The importance of taking precautions to avoid microbial contamination, meeting all applicable regulations, and clearly marking and packaging probiotic products is also emphasized. In addition, it reviews the clinical evidence supporting the possible health advantages of probiotics and investigates the processes through which probiotics enhance health. The review continues by stressing the significance of educating and informing consumers about probiotics and their proper use in order to maximize health benefits. Probiotics' potential health benefits can be maximized and consumer faith in these helpful microbes can be bolstered by adopting thorough quality management measures to ensure their safety, efficacy, and consistency.

Advancing Insights into Probiotics during Vegetable Fermentation

Fermented vegetables have a long history and are enjoyed worldwide for their unique flavors and health benefits. The process of fermentation improves the nutritional value, taste, and shelf life of foods. Microorganisms play a crucial role in this process through the production of metabolites. The flavors of fermented vegetables are closely related to the evaluation and succession of microbiota. Lactic acid bacteria (LABs) are typically the dominant bacteria in fermented vegetables, and they help inhibit the growth of spoilage bacteria and maintain a healthy gut microbiota in humans. However, homemade and small-scale artisanal products rely on spontaneous fermentation using bacteria naturally present on fresh vegetables or from aged brine, which may introduce external microorganisms and lead to spoilage and substandard products. Hence, understanding the role of LABs and other probiotics in maintaining the quality and safety of fermented vegetables is essential. Additionally, selecting probiotic fermentation microbiota and isolating beneficial probiotics from fermented vegetables can facilitate the use of safe and healthy starter cultures for large-scale industrial production. This review provides insights into the traditional fermentation process of making fermented vegetables, explains the mechanisms involved, and discusses the use of modern microbiome technologies to regulate fermentation microorganisms and create probiotic fermentation microbiota for the production of highly effective, wholesome, safe, and healthy fermented vegetable foods.

Postbiotics in the medical field under the perspective of the ISAPP definition: scientific, regulatory, and marketing considerations

Diverse terms have been used in the literature to refer to the health benefits obtained from the administration of non-viable microorganisms or their cell fragments and metabolites. In an effort to provide continuity to this emerging field, the International Scientific Association of Probiotics and Prebiotics (ISAPP) convened a panel of experts to consider this category of substances and adopted the term postbiotic, which they defined as a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host." This definition does not stipulate any specific health benefit, finished product, target population or regulatory status. In this perspective article, we focused on postbiotics developed for pharmaceutical uses, including medicinal products and medical devices. We address how this field is regulated for products based on inanimate microorganisms, marketing considerations and existing examples of postbiotics products developed as cosmetics for the skin, for vaginal health, and as orally consumed products. We focus on the European Union for regulatory aspects, but also give examples from other geographical areas.

Novel, non-colonizing, single-strain live biotherapeutic product ADS024 protects against Clostridioides difficile infection challenge in vivo

BACKGROUND

The Centers for Disease Control and Prevention estimate that Clostridioides difficile (C. difficile) causes half a million infections (CDI) annually and is a major cause of total infectious disease death in the United States, causing inflammation of the colon and potentially deadly diarrhea. We recently reported the isolation of ADS024, a Bacillus velezensis (B. velezensis) strain, which demonstrated direct in vitro bactericidal activity against C. difficile, with minimal collateral impact on other members of the gut microbiota. In this study, we hypothesized that in vitro activities of ADS024 will translate in vivo to protect against CDI challenge in mouse models.

AIM

To investigate the in vivo efficacy of B. velezensis ADS024 in protecting against CDI challenge in mouse models.

METHODS

To mimic disruption of the gut microbiota, the mice were exposed to vancomycin prior to dosing with ADS024. For the mouse single-dose study, the recovery of ADS024 was assessed via microbiological analysis of intestinal and fecal samples at 4 h, 8 h, and 24 h after a single oral dose of 5 × 108 colony-forming units (CFU)/mouse of freshly grown ADS024. The single-dose study in miniature swine included groups that had been pre-dosed with vancomycin and that had been exposed to a dose range of ADS024, and a group that was not pre-dosed with vancomycin and received a single dose of ADS024. The ADS024 colonies [assessed by quantitative polymerase chain reaction (qPCR) using ADS024-specific primers] were counted on agar plates. For the 28-d miniature swine study, qPCR was used to measure ADS024 levels from fecal samples after oral administration of ADS024 capsules containing 5 × 109 CFU for 28 consecutive days, followed by MiSeq compositional sequencing and bioinformatic analyses to measure the impact of ADS024 on microbiota. Two studies were performed to determine the efficacy of ADS024 in a mouse model of CDI: Study 1 to determine the effects of fresh ADS024 culture and ADS024 spore preparations on the clinical manifestations of CDI in mice, and Study 2 to compare the efficacy of single daily doses vs dosing 3 times per day with fresh ADS024. C. difficile challenge was performed 24 h after the start of ADS024 exposure. To model the human distal colon, an anerobic fecal fermentation system was used. MiSeq compositional sequencing and bioinformatic analyses were performed to measure microbiota diversity changes following ADS024 treatment. To assess the potential of ADS024 to be a source of antibiotic resistance, its susceptibility to 18 different antibiotics was tested.

RESULTS

In a mouse model of CDI challenge, single daily doses of ADS024 were as efficacious as multiple daily doses in protecting against subsequent challenge by C. difficile pathogen-induced disease. ADS024 showed no evidence of colonization based on the observation that the ADS024 colonies were not recovered 24 h after single doses in mice or 72 h after single doses in miniature swine. In a 28-d repeat-dose study in miniature swine, ADS024 was not detected in fecal samples using plating and qPCR methods. Phylogenetic analysis performed in the human distal colon model showed that ADS024 had a selective impact on the healthy human colonic microbiota, similarly to the in vivo studies performed in miniature swine. Safety assessments indicated that ADS024 was susceptible to all the antibiotics tested, while in silico testing revealed a low potential for off-target activity or virulence and antibiotic-resistance mechanisms.

CONCLUSION

Our findings, demonstrating in vivo efficacy of ADS024 in protecting against CDI challenge in mouse models, support the use of ADS024 in preventing recurrent CDI following standard antibiotic treatment.

Antibiotic Resistance and Probiotics: Knowledge Gaps, Market Overview and Preliminary Screening

Probiotics are among those products, the use of which is increasing, and they are available primarily as food/dietary supplements, as well as in the form of medicines. This study aims to assess the attitudes and practices of health professionals and students of health sciences, give a short overview of the probiotics currently on the market, and conduct a screening of five food supplements and one drug with respect to antibiotic resistance. Nearly half of the respondents in our survey state that probiotics have no side effects, while only 6.3% believe that the use of probiotics can lead to antibiotic resistance. In addition, more than 40% of the participants throw unused probiotics into municipal waste. The market analysis results indicate that probiotic products on the Serbian market have highly variable CFU counts, while the declared health claims cover numerous beneficial health effects, and they are sometimes even registered as medicines. Lactobacilli are frequently present in probiotic supplements, and are sold in pharmacies and online. The experimental results showed that antibiotic resistance is present in different types of lactobacilli in probiotic products. The risk of using probiotics, regardless of their beneficial health effects, should be taken into account in the future. An update to the regulations governing probiotics, including a stipulation for antimicrobial resistance (AMR) testing, should be established, and guidelines for their proper use and disposal put into place.

Probiotics, Live Biotherapeutic Products (LBPs), and Gut-Brain Axis Related Psychological Conditions: Implications for Research and Dietetics

It is well-known that probiotics have key roles in the crosstalk between the gut and brain in terms of nutrition and health. However, when investigating their role in nutrition and health, it can be important to discriminate probiotics used as foods, food supplements, or drugs. For clarification of this terminology, the Food and Drug Administration (FDA) has established a new "live biotherapeutic products" (LBP) category, expressing pharmaceutical expectations and to reduce confusion in the literature. Growing evidence advises that the community of microorganisms found in the gut microbiota is associated with psychological conditions. Hence, it is thought that LBPs may positively affect depression, anxiety, bipolar disorder, and schizophrenia by reducing inflammation, improving gut microbiota, and balancing gut neurometabolites. This review focuses on the specific position of probiotics as LBPs in psychological conditions. Condition-specific potential pathways and mechanisms of LBPs and the prominent strains are discussed in the light of novel studies for future research, dietetic and pharmaceutical applications.

Engineering bacteria to modulate host metabolism

The microbial community of the gut, collectively termed the gut microbiota, modulates both host metabolism and disease development in a variety of clinical contexts. The microbiota can have detrimental effects and be involved in disease development and progression, but it can also offer benefits to the host. This has led in the last years to the development of different therapeutic strategies targeting the microbiota. In this review, we will focus on one of these strategies that involve the use of engineered bacteria to modulate gut microbiota in the treatment of metabolic disorders. We will discuss the recent developments and challenges in the use of these bacterial strains with an emphasis on their use for the treatment of metabolic diseases.

Beneficial Bacteria Isolated from Food in Relation to the Next Generation of Probiotics

Recently, probiotics are increasingly being used for human health. So far, only lactic acid bacteria isolated from the human gastrointestinal tract were recommended for human use as probiotics. However, more authors suggest that probiotics can be also isolated from unconventional sources, such as fermented food products of animal and plant origin. Traditional fermented products are a rich source of microorganisms, some of which may have probiotic properties. A novel category of recently isolated microorganisms with great potential of health benefits are next-generation probiotics (NGPs). In this review, general information of some "beneficial microbes", including NGPs and acetic acid bacteria, were presented as well as essential mechanisms and microbe host interactions. Many reports showed that NGP selected strains and probiotics from unconventional sources exhibit positive properties when it comes to human health (i.e., they have a positive effect on metabolic, human gastrointestinal, neurological, cardiovascular, and immune system diseases). Here we also briefly present the current regulatory framework and requirements that should be followed to introduce new microorganisms for human use. The term "probiotic" as used herein is not limited to conventional probiotics. Innovation will undoubtedly result in the isolation of potential probiotics from new sources with fascinating new health advantages and hitherto unforeseen functionalities.

Pharmacomicrobiomics of Antidepressants in Depression: A Systematic Review

This systematic review evaluated the animal and human evidence for pharmacomicrobiomics (PMx) interactions of antidepressant medications. Studies of gut microbiota effects on functional and behavioral effects of antidepressants in human and animal models were identified from PubMed up to December 2022. Risk of bias was assessed, and results are presented as a systematic review following PRISMA guidelines. A total of 28 (21 animal, 7 human) studies were included in the review. The reviewed papers converged on three themes: (1) Antidepressants can alter the composition and metabolites of gut microbiota, (2) gut microbiota can alter the bioavailability of certain antidepressants, and (3) gut microbiota may modulate the clinical or modeled mood modifying effects of antidepressants. The majority (n = 22) of studies had at least moderate levels of bias present. While strong evidence is still lacking to understand the clinical role of antidepressant PMx in human health, there is evidence for interactions among antidepressants, microbiota changes, microbiota metabolite changes, and behavior. Well-controlled studies of the mediating and moderating effects of baseline and treatment-emergent changes in microbiota on therapeutic and adverse responses to antidepressants are needed to better establish a potential role of PMx in personalizing antidepressant treatment selection and response prediction.

Photodynamic Therapy, Probiotics, Acetic Acid, and Essential Oil in the Treatment of Chronic Wounds Infected with Pseudomonas aeruginosa

As a prevalent medical problem that burdens millions of patients across the world, chronic wounds pose a challenge to the healthcare system. These wounds, often existing as a comorbidity, are vulnerable to infections. Consequently, infections hinder the healing process and complicate clinical management and treatment. While antibiotic drugs remain a popular treatment for infected chronic wounds, the recent rise of antibiotic-resistant strains has hastened the need for alternative treatments. Future impacts of chronic wounds are likely to increase with aging populations and growing obesity rates. With the need for more effective novel treatments, promising research into various wound therapies has seen an increased demand. This review summarizes photodynamic therapy, probiotics, acetic acid, and essential oil studies as developing antibiotic-free treatments for chronic wounds infected with Pseudomonas aeruginosa. Clinicians may find this review informative by gaining a better understanding of the state of current research into various antibiotic-free treatments. Furthermore. this review provides clinical significance, as clinicians may seek to implement photodynamic therapy, probiotics, acetic acid, or essential oils into their own practice.

pH-sustaining nanostructured hydroxyapatite/alginate composite hydrogel for gastric protection and intestinal release of Lactobacillus rhamnosusGG

The gut microbiome is closely linked to gastrointestinal health and disease status. Oral administration of known probiotic strains is now considered a promising therapeutic strategy, especially for refractory diseases such as inflammatory bowel disease. In this study, we developed a nanostructured hydroxyapatite/alginate (HAp/Alg) composite hydrogel that protects its encapsulated probiotic Lactobacillus rhamnosus GG (LGG) by neutralizing hydrogen ions that penetrate the hydrogel in a stomach without inhibiting LGG release in an intestine. Surface and transection analyses of the hydrogel revealed characteristic patterns of crystallization and composite-layer formation. TEM revealed the dispersal of the nanosized HAp crystals and encapsulated LGG in the Alg hydrogel networks. The HAp/Alg composite hydrogel maintained its internal microenvironmental pH, thereby enabling the LGG to survive for substantially longer. At intestinal pH, the encapsulated LGG was completely released upon disintegration of the composite hydrogel. In a dextran sulfate sodium-induced colitis mouse model, we then assessed the therapeutic effect of the LGG-encapsulating hydrogel. This achieved intestinal delivery of LGG with minimal loss of enzymatic function and viability, ameliorating colitis by reducing epithelial damage, submucosal edema, inflammatory cell infiltration, and the number of goblet cells. These findings reveal the HAp/Alg composite hydrogel as a promising intestinal-delivery platform for live microorganisms including probiotics and live biotherapeutic products.

Synergistic cancer immunotherapy utilizing programmed Salmonella typhimurium secreting heterologous flagellin B conjugated to interleukin-15 proteins

The use of appropriately designed immunotherapeutic bacteria is an appealing approach to tumor therapy because the bacteria specifically target tumor tissue and deliver therapeutic payloads. The present study describes the engineering of an attenuated strain of Salmonella typhimurium deficient in ppGpp biosynthesis (SAM) that could secrete Vibrio vulnificus flagellin B (FlaB) conjugated to human (hIL15/FlaB) and mouse (mIL15/FlaB) interleukin-15 proteins in the presence of L-arabinose (L-ara). These strains, named SAMphIF and SAMpmIF, respectively, secreted fusion proteins that retained bioactivity of both FlaB and IL15. SAMphIF and SAMpmIF inhibited the growth of MC38 and CT26 subcutaneous (sc) tumors in mice and increased mouse survival rate more efficiently than SAM expressing FlaB alone (SAMpFlaB) or IL15 alone (SAMpmIL15 and SAMphIL15), although SAMpmIF had slightly greater antitumor activity than SAMphIF. The mice treated with these bacteria showed enhanced macrophage phenotype shift, from M2-like to M1-like, as well as greater proliferation and activation of CD4⁺ T, CD8⁺ T, NK, and NKT cells in tumor tissues. After tumor eradication by these bacteria, ≥50% of the mice show no evidence of tumor recurrence upon rechallenge with the same tumor cells, indicating that they had acquired long-term immune memory. Treatment of mice of 4T1 and B16F10 highly malignant sc tumors with a combination of these bacteria and an immune checkpoint inhibitor, anti-PD-L1 antibody, significantly suppressed tumor metastasis and increased mouse survival rate. Taken together, these findings suggest that SAM secreting IL15/FlaB is a novel therapeutic candidate for bacterial-mediated cancer immunotherapy and that its antitumor activity is enhanced by combination with anti-PD-L1 antibody.

Patent landscape analysis-Contributing to the identification of technology trends and informing research and innovation funding policy

Patents and the systematic analysis thereof provide important decision information for a range of stakeholders pursuing diverse goals. However, in particular academia and small-scale private sector innovators underappreciate the value of patent information for identifying research gaps, ensuring originality of their work and, in turn, maximisation of limited (public) funds. By the same token, pertinent public sector organisations, such as regulators, require overviews of potentially upcoming technologies to adequately adapt regulatory protocols. The latter, in particular if contemporary scientific evidence is not sufficient, can require a substantial amount of time and lead to a delay in the marketing of important innovations. Patent landscape analysis (PLA) is a very useful method to create overviews of technology fields and thereby indicate if, inter alia, a specific line of scientific enquiry and its application have already been pursued or potential regulatory gaps will exist in the near- to mid-term future. The objective of this communication is to increase awareness of the utility of patent information and provide support in retrieval and analysis of pertinent information for those involved in biotech R&D. Based on Espacenet, a patent search engine, we provide basic guidance on search strategy development, piloting and execution, and data preparation and analysis. To highlight the value of PLA, we also summarise selected results of a PLA we performed recently for microbiome targeting interventions, also referred to as live biotherapeutic products.

Strategizing the human microbiome for small molecules: Approaches and perspectives

Studies of the human microbiome are providing a deeper understanding of its significance to human health, and increasing evidence links the microbiota with several diseases. Nevertheless, the exact mechanisms involved in human-microbe interactions are mostly undefined. The genomic potential of the human microbiome to biosynthesize distinct molecules outmatches its known chemical space, and small-molecule discovery in this context remains in its infancy. The profiling of microbiome-derived small molecules and their contextualization through cause-effect mechanistic studies may provide a better understanding of host-microbe interactions, guide new therapeutic interventions, and modulate microbiome-based therapies. This review describes the advances, approaches, and allied challenges in mining new microbial scaffolds from the human microbiome using genomic, microbe cultivation, and chemical analytic platforms. In the future, the complete biological characterization of a single microbe-derived molecule that has a specific therapeutic application could resolve the current limitations of microbiota-modulating therapies.

Emerging Options for the Prevention and Management of Clostridioides difficile Infection

Agents in development for the prevention or treatment of Clostridioides difficile infection can be split into three broad categories: antibiotics, microbiome restoration, and vaccines. Given the extensive list of agents currently in development, this narrative review will focus on agents that have progressed into late-stage clinical trials, defined as having a Phase III clinical trial registered on ClinicalTrials.gov. These agents include one antibiotic (ridinilazole), three live biotherapeutic products (LBPs) (CP101, RBX2660, and SER109), and two toxoid vaccines (PF06425090 and a second toxoid vaccine). As new prevention and treatment strategies enter the market, clinicians and administrators will need knowledge of these products to make rational decisions on how best to adopt them into clinical practice.

Gut microbiota changes associated with Clostridioides difficile infection and its various treatment strategies

Human gut microbiota are critical to both the development of and recovery from Clostridioides difficile infection (CDI). Antibiotics are the mainstay of CDI treatment, yet inherently cause further imbalances in the gut microbiota, termed dysbiosis, complicating recovery. A variety of microbiota-based therapeutic approaches are in use or in development to limit disease- and treatment-associated dysbiosis and improve rates of sustained cure. These include the recently FDA-approved fecal microbiota, live-jslm (formerly RBX2660) and fecal microbiota spores, live-brpk (formerly SER-109), which represent a new class of live biotherapeutic products (LBPs), traditional fecal microbiota transplantation (FMT), and ultra-narrow-spectrum antibiotics. Here, we aim to review the microbiome changes associated with CDI as well as a variety of microbiota-based treatment approaches.

Gut-oriented disease modifying therapy for Parkinson's disease

Neuropathology studies have shown that the pathognomonic feature of Parkinson's disease (PD), one of the most common neurodegenerative disorders, may start from the gut enteric nervous system and then spread to the central dopaminergic neurons through the gut-brain axis. With the advent of metagenomic sequencing and metabolomic analysis, a plethora of evidence has revealed different gut microbiomes and gut metabolites in patients with PD compared with unaffected controls. Currently, although dopaminergic treatments and deep brain stimulation can provide some symptomatic benefits for motor symptoms of the disease, their long-term use is problematic. A mechanism-targeted therapy to halt the neurodegeneration is lacking. The recently observed gut microenvironmental changes in the early stages of the disease play a vital role in the PD pathogenesis. Patients whose disease begins in the gut may benefit most from interventions that target the gut microenvironments. In this review, we will summarize the current studies demonstrating multifunctional roles of gut microbiota in the gut-brain axis of PD and the currently available evidence for targeting the gut microbiota as a novel approach to potential disease-modifying therapy in PD.

Microbiological quality of probiotic products

Microorganisms used as probiotics should meet elementary safety aspects (non-toxicity, absence of antibiotic resistance genes and translocation) and functional/technological aspects (resistance and survival in the acid gastric environment, adhesiveness, stability, and cell viability). Probiotics with the health claim of being a dietary product or a pharmabiotic (drug category) should be clinically tested, validated, documented, and continuously controlled for quality. Important quality parameters include the identification of declared probiotic strains, the number of viable microorganisms (probiotic bacteria and/or fungi), and microbiological purity (absence of specified pathogenic/opportunistic pathogenic bacteria and fungi, and limitation of total unspecified contaminants such as aerobic bacteria, yeasts, and molds). Due to numerous reports of low-quality commercial probiotics marketed for human use, this review discusses the methods used to test the probiotic microorganism content, safety for the intended use, and proven health benefits of those probiotics whose microbiological quality deviates from the manufacturer's stated content, as well as the maintenance of cell viability, i.e., stability of the probiotic during the shelf life. In addition, the adverse effects of probiotics and the potential hazards to the health of the user are addressed.

Randomised clinical trial: efficacy and safety of the live biotherapeutic product MRx1234 in patients with irritable bowel syndrome

BACKGROUND

MRx1234 is a live biotherapeutic product that contains a strain of Blautia hydrogenotrophica. It is in development for the treatment of irritable bowel syndrome (IBS).

AIMS

To assess the efficacy and safety of MRx1234 in patients with IBS with predominant constipation (IBS-C) or diarrhoea (IBS-D) METHODS: We conducted a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial. Patients aged 18-70 years in two parallel cohorts (IBS-C; IBS-D) were randomised (1:1) to MRx1234 or placebo for 8 weeks. The primary efficacy endpoint was overall responder rate-a composite of improved bowel habit (IBS-C: stool frequency; IBS-D: stool consistency) and abdominal pain intensity-for ≥50% of the treatment period in each cohort. Statistical testing was at a one-sided 0.10 significance level.

RESULTS

Of 366 randomised patients (164 IBS-C; 202 IBS-D), 365 received any study medication (177 MRx1234, 188 placebo). Numerically, although not statistically significantly different, more patients who received MRx1234 than placebo were overall responders in the IBS-C (25.0% vs. 17.1%) and IBS-D (23.4% vs. 17.8%) cohorts. Similar results were observed in the additional combined cohort analysis (24.1% vs. 17.5%; p = 0.063). For the components of the primary endpoint, significantly more patients on MRx1234 than placebo reported improvement in bowel habit in the IBS-C, IBS-D and combined cohorts, while improvements in abdominal pain were observed in each cohort. The safety profile of MRx1234 was similar to placebo.

CONCLUSIONS

MRx1234 has the potential to become a novel, safe treatment option for patients with IBS-C or IBS-D, and for those who have mixed symptoms or transition between subtypes.

CLINICALTRIALS

gov #NCT03721107.

From fecal microbiota transplantation toward next-generation beneficial microbes: The case of Anaerobutyricum soehngenii

The commensal gut microbiota is important for human health and well-being whereas deviations of the gut microbiota have been associated with a multitude of diseases. Restoration of a balanced and diverse microbiota by fecal microbiota transplantation (FMT) has emerged as a potential treatment strategy and promising tool to study causality of the microbiota in disease pathogenesis. However, FMT comes with logistical challenges and potential safety risks, such as the transfer of pathogenic microorganisms, undesired phenotypes or an increased risk of developing disease later in life. Therefore, a more controlled, personalized mixture of cultured beneficial microbes might prove a better alternative. Most of these beneficial microbes will be endogenous commensals to the host without a long history of safe and beneficial use and are therefore commonly referred to as next-generation probiotics (NGP) or live biotherapeutic products (LBP). Following a previous FMT study within our group, the commensal butyrate producer Anaerobutyricum spp. (previously named Eubacterium hallii) was found to be associated with improved insulin-sensitivity in subjects with the metabolic syndrome. After the preclinical testing with Anaerobutyricum soehngenii in mice models was completed, the strain was produced under controlled conditions and several clinical studies evaluating its safety and efficacy in humans were performed. Here, we describe and reflect on the development of A. soehngenii for clinical use, providing practical guidance for the development and testing of NGPs and reflecting on the current regulatory framework.

Recent developments in the probiotics as live biotherapeutic products (LBPs) as modulators of gut brain axis related neurological conditions

Probiotics have been defined as “living microorganisms that create health benefits in the host when taken in sufficient amounts. Recent developments in the understanding of the relationship between the microbiom and its host have shown evidence about the promising potential of probiotics to improve certain health problems. However, today, there are some confusions about traditional and new generation foods containing probiotics, naming and classifications of them in scientific studies and also their marketing. To clarify this confusion, the Food and Drug Administration (FDA) declared that it has made a new category definition called "live biotherapeutic products" (LBPs). Accordingly, the FDA has designated LBPs as “a biological product that: i)contains live organisms, such as bacteria; ii)is applicable to the prevention, treatment, or cure of a disease/condition of human beings; and iii) is not a vaccine”. The accumulated literature focused on LBPs to determine effective strains in health and disease, and often focused on obesity, diabetes, and certain diseases like inflammatory bowel disease (IBD).However, microbiome also play an important role in the pathogenesis of diseases that age day by day in the modern world via gut-brain axis. Herein, we discuss the novel roles of LBPs in some gut-brain axis related conditions in the light of recent studies. This article may be of interest to a broad readership including those interested in probiotics as LBPs, their health effects and safety, also gut-brain axis.

Innovations for microbiome targeting interventions - a patent landscape analysis indicating overall patenting activity decline and promising target disease areas

The human microbiota have been implicated in the aetiology and remedy of a host of disorders. However, due to the pervasive uncertainty inherent in the field of microbiota-targeting interventions and associated issues with establishing rigorous safety and efficacy profiles, regulatory oversight is suboptimal. This can dissuade innovators from further exploring novel and much needed health interventions. Modification of regulatory protocols and practices requires focussed efforts and funding to build the evidence base around future regulatory needs. Such modification can be critically informed by identification of changes and trends in technology fields to facilitate identification of regulatory gaps. To this purpose, this study rigorously collected and analysed patent data from Espacenet - covering the years 2013-2018 - and created a patent landscape analysis of microbiome targeting interventions with a focus on medicinal products. Pertinent patenting activity has declined overall. While, in absolute terms, patents most frequently claimed inventions targeting disorders of the gut and alimentary tract, relative year-on-year interest increases have been substantial for cancer, and disorders of the (neuro-)muscular and respiratory systems - driven by the private sector. Academic stakeholders showed top interest in disorders of the metabolism, anti-infectives, and skeletal and dermatological diseases. Although medicinal preparation claims dominated our dataset, a third of patents claimed food preparations, while only 1% claimed application as a diagnostic. Finally, China is, by an inordinate margin, a market of particular interest for both domestic and foreign innovators, indicating that microbiome targeting intervention innovation for EU and US markets might be frustrated. This study is the first to empirically demonstrate that live biotherapeutic product innovation is decelerating and potentially frustrated, supporting the urgent need for improved regulatory standards. Our results indicate which disease areas deserve particular attention for research funding to facilitate proper regulatory appraisal in the near- to mid-term future.

Akkermansia muciniphila: paradigm for next-generation beneficial microorganisms

Ever since Akkermansia muciniphila was discovered and characterized two decades ago, numerous studies have shown that the lack or decreased abundance of this commensal bacterium was linked with multiple diseases (such as obesity, diabetes, liver steatosis, inflammation and response to cancer immunotherapies). Although primarily based on simple associations, there are nowadays an increasing number of studies moving from correlations to causality. The causal evidence derived from a variety of animal models performed in different laboratories and recently was also recapitulated in a human proof-of-concept trial. In this Review, we cover the history of the discovery of A. muciniphila and summarize the numerous findings and main mechanisms of action by which this intestinal symbiont improves health. A comparison of this microorganism with other next-generation beneficial microorganisms that are being developed is also made.

Lactobacilli: Legal Regulation and Prospects for New Generation Drugs

The global probiotics industry has been undergoing major changes in recent years. Approaches to finding and creating new probiotics, as well as a paradigm of their use in food, medicine, and pharmacology are changing. The catalyst proved to be the increasing popularity and availability of omics technologies, in particular, metagenomic studies of human and animal microbiomes. However, the efficiency and safety of drugs based on probiotic strains, as well as their marketing rates, largely depend on the levels of legal and technical regulation in the field. The present review discusses the aspects of legal regulation in Russia, the European Union and the United States, along with the advantages and disadvantages of probiotics and postbiotics. A consensus is emerging that postbiotics have a number of advantages over classical live probiotic cultures. The review also focuses on the lactobacilli family, which includes the largest number of probiotic strains studied so far and still holds a leading position among probiotics. On the legislative front, Russia is often ahead of its time with adopting such laws as the Federal Law No. 492-FZ on biosecurity, which defined the concept of human and animal microbiota and set forth legislative guidelines for its preservation. The new field of research referred to as microbiome nutrigenomics aims to achieve this goal.

Ameliorative effect of the probiotic peptide against benzo(α)pyrene-induced inflammatory damages in enterocytes

Probiotics are living bacteria that provide health benefits to the host when consumed in sufficient quantities. However, the protective effect of the bioactive peptides isolated from the probiotics against benzo(α)pyrene (BaP) induced gastrointestinal injury has never been investigated. The current work used a bio-assay guided technique to identify-four new cyclic peptides in BaP-induced Caco-2 cell culture and mouse colitis model. Lactobacillus rhamnosus cycle (Thr-His-Ala-Trp) peptide-1 (LRCP-1) effectively inhibited BaP-induced epithelial cytokine over-release and intracellular ROS over-production. Simultaneously, LRCP-1 attenuated BaP-induced NAD (P)H: oxidases (NOXs), Matrix metalloproteinases (MMPs) over-expression, respectively. Furthermore, increased NAD (P)H: quinone oxidoreductase 1 (NQO1)/heme oxygenase-1 (HO-1)/nuclear factor E2-related factor 2 (Nrf2) expression and aryl hydrocarbon receptor (AhR) pathway activation induced by the BaP-exposure were also inhibited after the LRCP-1 treatment. Notably, LRCP-1 is a promising agent protecting gastrointestinal epithelial cells from BaP-induced inflammatory and oxidative damages.

Lactobacillus plantarum ST-III culture supernatant ameliorates alcohol-induced cognitive dysfunction by reducing endoplasmic reticulum stress and oxidative stress

Background

Long-term alcohol exposure is associated with oxidative stress, endoplasmic reticulum (ER) stress, and neuroinflammation, which may impair cognitive function. Probiotics supplements can significantly improve cognitive function in neurodegenerative diseases such as Alzheimer’s disease. Nevertheless, the effect of Lactobacillus plantarum ST-III culture supernatant (LP-cs) on alcohol-induced cognitive dysfunction remains unclear.

Methods

A mouse model of cognitive dysfunction was established by intraperitoneal injection of alcohol (2 g/kg body weight) for 28 days. Mice were pre-treated with LP-cs, and cognitive function was evaluated using the Morris water maze test. Hippocampal tissues were collected for biochemical and molecular analysis.

Results

LP-cs significantly ameliorated alcohol-induced decline in learning and memory function and hippocampal morphology changes, neuronal apoptosis, and synaptic dysfunction. A mechanistic study showed that alcohol activated protein kinase R-like endoplasmic reticulum kinase (PERK) signaling and suppressed brain derived neurotrophic factor (BDNF) levels via ER stress in the hippocampus, which LP-cs reversed. Alcohol activated oxidative stress and inflammation responses in the hippocampus, which LP-cs reversed.

Conclusion

LP-cs significantly ameliorated alcohol-induced cognitive dysfunction and cellular stress. LP-cs might serve as an effective treatment for alcohol-induced cognitive dysfunction.

Achieving spatially precise diagnosis and therapy in the mammalian gut using synthetic microbial gene circuits

The mammalian gut and its microbiome form a temporally dynamic and spatially heterogeneous environment. The inaccessibility of the gut and the spatially restricted nature of many gut diseases translate into difficulties in diagnosis and therapy for which novel tools are needed. Engineered bacterial whole-cell biosensors and therapeutics have shown early promise at addressing these challenges. Natural and engineered sensing systems can be repurposed in synthetic genetic circuits to detect spatially specific biomarkers during health and disease. Heat, light, and magnetic signals can also activate gene circuit function with externally directed spatial precision. The resulting engineered bacteria can report on conditions in situ within the complex gut environment or produce biotherapeutics that specifically target host or microbiome activity. Here, we review the current approaches to engineering spatial precision for in vivo bacterial diagnostics and therapeutics using synthetic circuits, and the challenges and opportunities this technology presents.

Probiotics and live biotherapeutic products aiming at cancer mitigation and patient recover

Molecular biology techniques allowed access to non-culturable microorganisms, while studies using analytical chemistry, as Liquid Chromatography and Tandem Mass Spectrometry, showed the existence of a complex communication system among bacteria, signaled by quorum sensing molecules. These approaches also allowed the understanding of dysbiosis, in which imbalances in the microbiome diversity, caused by antibiotics, environmental toxins and processed foods, lead to the constitution of different diseases, as cancer. Colorectal cancer, for example, can originate by a dysbiosis configuration, which leads to biofilm formation, production of toxic metabolites, DNA damage in intestinal epithelial cells through the secretion of genotoxins, and epigenetic regulation of oncogenes. However, probiotic strains can also act in epigenetic processes, and so be use for recovering important intestinal functions and controlling dysbiosis and cancer mitigation through the metabolism of drugs used in chemotherapy, controlling the proliferation of cancer cells, improving the immune response of the host, regulation of cell differentiation and apoptosis, among others. There are still gaps in studies on the effectiveness of the use of probiotics, therefore omics and analytical chemistry are important approaches to understand the role of bacterial communication, formation of biofilms, and the effects of probiotics and microbiome on chemotherapy. The use of probiotics, prebiotics, synbiotics, and metabiotics should be considered as a complement to other more invasive and hazard therapies, such chemotherapy, surgery, and radiotherapy. The study of potential bacteria for cancer treatment, as the next-generation probiotics and Live Biotherapeutic Products, can have a controlling action in epigenetic processes, enabling the use of these bacteria for the mitigation of specific diseases through changes in the regulation of genes of microbiome and host. Thus, it is possible that a path of medicine in the times to come will be more patient-specific treatments, depending on the environmental, genetic, epigenetic and microbiome characteristics of the host.

Drugs and Bugs: The Gut-Brain Axis and Substance Use Disorders

Substance use disorders (SUDs) represent a significant public health crisis. Worldwide, 5.4% of the global disease burden is attributed to SUDs and alcohol use, and many more use psychoactive substances recreationally. Often associated with comorbidities, SUDs result in changes to both brain function and physiological responses. Mounting evidence calls for a precision approach for the treatment and diagnosis of SUDs, and the gut microbiome is emerging as a contributor to such disorders. Over the last few centuries, modern lifestyles, diets, and medical care have altered the health of the microbes that live in and on our bodies; as we develop, our diets and lifestyle dictate which microbes flourish and which microbes vanish. An increase in antibiotic treatments, with many antibiotic interventions occurring early in life during the microbiome's normal development, transforms developing microbial communities. Links have been made between the microbiome and SUDs, and the microbiome and conditions that are often comorbid with SUDs such as anxiety, depression, pain, and stress. A better understanding of the mechanisms influencing behavioral changes and drug use is critical in developing novel treatments for SUDSs. Targeting the microbiome as a therapeutic and diagnostic tool is a promising avenue of exploration. This review will provide an overview of the role of the gut-brain axis in a wide range of SUDs, discuss host and microbe pathways that mediate changes in the brain's response to drugs, and the microbes and related metabolites that impact behavior and health within the gut-brain axis.

Microbial metabolites: cause or consequence in gastrointestinal disease?

Systems biology studies have established that changes in gastrointestinal microbiome composition and function can adversely impact host physiology. Notable diseases synonymously associated with dysbiosis include inflammatory bowel diseases, cancer, metabolic disorders, and opportunistic and recurrent pathogen infections. However, there is a scarcity of mechanistic data that advances our understanding of taxonomic correlations with pathophysiological host-microbiome interactions. Generally, to survive a hostile gut environment, microbes are highly metabolically active and produce trans-kingdom signaling molecules to interact with competing microorganisms and the host. These specialized metabolites likely play important homeostatic roles, and identifying disease-specific taxa and their effector pathways can provide better strategies for diagnosis, treatment, and prevention, as well as the discovery of innovative therapeutics. The signaling role of microbial biotransformation products such as bile acids, short-chain fatty acids, polysaccharides, and dietary tryptophan is increasingly recognized, but little is known about the identity and function of metabolites that are synthesized by microbial biosynthetic gene clusters, including ribosomally synthesized and posttranslationally modified peptides (RiPPs), nonribosomal peptides (NRPs), polyketides (PKs), PK-NRP hybrids, and terpenes. Here we consider how bioactive natural products directly encoded by the human microbiome can contribute to the pathophysiology of gastrointestinal disease, cancer, autoimmune, antimicrobial-resistant bacterial and viral infections (including COVID-19). We also present strategies used to discover these compounds and the biological activities they exhibit, with consideration of therapeutic interventions that could emerge from understanding molecular causation in gut microbiome research.