Probiotic Escherichia coli NISSLE 1917 for inflammatory bowel disease applications

Non-pathogenic Trojan horse Nissle1917 triggers mitophagy through PINK1/Parkin pathway to discourage colon cancer

Bacteria-mediated antitumor therapy has gained widespread attention for its innate tumor-targeting capability and excellent immune activation properties. Nevertheless, the clinical approval of bacterial therapies remains elusive primarily due to the formidable challenge of balancing safety with enhancing in vivo efficacy. In this study, leveraging the probiotic Escherichia coli Nissle1917 (EcN) emerges as a promising approach for colon cancer therapy, offering a high level of safety attributed to its lack of virulence factors and its tumor-targeting potential owing to its obligate anaerobic nature. Specifically, we delineate the erythrocyte (RBC) membrane-camouflaged EcN, termed as Trojan horse EcN@RBC, which triggers apoptosis in tumor cells by mitigating mitochondrial membrane potential (MMP) and subsequently activating the PINK1/Parkin pathway associated with mitophagy. Concurrently, the decline in MMP induced by mitophagy disrupts the mitochondrial permeability transition pore (MPTP), leading to the release of Cytochrome C and subsequent apoptosis induction. Moreover, synergistic effects were observed through the combination of the autophagy activator rapamycin, bolstering the antitumor efficacy in vivo. These findings offer novel insights into probiotic-mediated antitumor mechanisms and underscore the therapeutic potential of EcN@RBC for colon cancer patients.

Intracellularly Gelated Macrophages Loaded with Probiotics for Therapy of Colitis

Probiotics therapy has garnered significant attention in the treatment of inflammatory bowel disease (IBD). However, a large number of oral administrated probiotics are inactivated after passing through the gastric acid environment, and their ability to colonize in the intestine is also weak. Herein, this study develops a novel probiotics formulation (GM-EcN) by incorporating Escherichia coli Nissle 1917 (EcN) into intracellularly gelated macrophages (GM). Intracellular hydrogel is designed to load and prevent EcN from digestion in gastric juice, and GM acts as a macrophage-like carrier to carry the attached probiotics to colonize in the inflammatory intestine. In addition, hydrogel serves as an ideal cytoskeletal structure to maintain the intact cell morphology and membrane structure of GM, comparable to source macrophages. Due to the receptor-ligand interaction, inflammation-related membrane proteins enable GM as a cell sponge to sequestrate and neutralize multiple inflammatory cytokines. In vivo treatment demonstrates that GM-EcN efficiently alleviates IBD symptoms and enhances gut microbiota recovery.

Optimization of pH-responsive microgel for the co-delivery of Weizmannia coagulans and procyanidins to enhance survival rate and tolerance

The purpose of this study was to prepare a pH-responsive microgel for co-delivering Weizmannia coagulans 99 (BC99) and procyanidins (PCs) to enhance the survival rate and tolerance of probiotics in complex micro-environment. The effects of different concentrations of PCs on the properties of microgels were optimized, and found that the spherical microgels had higher encapsulation efficiency (90.27 ± 2.51%) and smaller size when the concentration of PCs was 20 μg/mL. The interaction among PCs, pectin and protein could effectively improve the survival rate of BC99 under different pH, bile salt, digestive enzyme and temperature conditions, maintain their stability in acidic gastric fluid, and realize the release of probiotics in neutral intestinal fluid. Moreover, the microgel was able to protect BC99 against H2O2 and antibiotics. This work provides a pH-responsive co-loaded microgels for BC99 and PCs, and has the potential in the loading and delivery of other probiotics and polyphenols.

Escherichia coli on colorectal cancer: A two-edged sword

Escherichia coli (E. coli) is a ubiquitous symbiotic bacterium in the gut, and the diversity of E. coli genes determines the diversity of its functions. In this review, the two-edged sword theory was innovatively proposed. For the question 'how can we harness the ambivalent nature of E. coli to screen and treat CRC?', in terms of CRC screening, the variations in the abundance and subtypes of E. coli across different populations present an opportunity to utilise it as a biomarker, while in terms of CRC treatment, the natural beneficial effect of E. coli on CRC may be limited, and engineered E. coli, particularly certain subtypes with probiotic potential, can indeed play a significant role in CRC treatment. It seems that the favourable role of E. coli as a genetic tool lies not in its direct impact on CRC but its potential as a research platform that can be integrated with various technologies such as nanoparticles, imaging methods, and synthetic biology modification. The relationship between gut microflora and CRC remains unclear due to the complex diversity and interaction of gut microflora. Therefore, the application of E. coli should be based on the 'One Health' view and take the interactions between E. coli and other microorganisms, host, and environmental factors, as well as its own changes into account. In this paper, the two-edged sword role of E. coli in CRC is emphasised to realise the great potential of E. coli in CRC screening and treatment.

Recent advances in bacteria-based platforms for inflammatory bowel diseases treatment

Inflammatory bowel disease (IBD) is a recurring chronic inflammatory disease. Current treatment strategies are aimed at alleviating clinical symptoms and are associated with gastrointestinal or systemic adverse effects. New delivery strategies are needed for the treatment of IBD. Bacteria are promising biocarriers, which can produce drugs in situ and sense the gut in real time. Herein, we focus on recent studies of engineered bacteria used for IBD treatment and introduce the application of engineered bacteria in the diagnosis. On this basis, the current dilemmas and future developments of bacterial delivery systems are discussed.

Microfluidic-based multifunctional microspheres for enhanced oral co-delivery of probiotics and postbiotics

Probiotic-based therapies have shown great potential in the prevention and treatment of many diseases by positively regulating intestinal flora homeostasis. However, the efficacy of oral probiotics is severely limited due to the loss of bioactivity, short intestinal retention time, and insufficient therapeutic effect. Here, based on droplet microfluidics, we developed a hydrogel microsphere with colonic targeting and mucoadhesive capabilities as a multifunctional delivery platform, which can be used for co-delivery of probiotics (Escherichia coli Nissle 1917, EcN) and auxiliary molecules (indole-3-propionic acid, IPA), achieving synergistic therapeutic effects. In vivo studies shown that the integrated multifunctional microspheres can significantly reduce intestinal inflammation, repair intestinal barrier function, enhance probiotic colonization in the intestine, and modulate disordered intestinal flora, demonstrating enhanced therapeutic effects in a mouse model of colitis. This work reveals that microfluidic-based smart droplet microspheres can provide a versatile platform for advanced microbial therapies.

Top-Down Characterization of Bacterial Lipopolysaccharides and Lipooligosaccharides Using Activated-Electron Photodetachment Mass Spectrometry

Lipopolysaccharides (LPS) and lipooligosaccharides (LOS) are located in the outer membrane of Gram-negative bacteria and are comprised of three distinctive parts: lipid A, core oligosaccharide (OS), and O-antigen. The structure of each region influences bacterial stability, toxicity, and pathogenesis. Here, we highlight the use of targeted activated-electron photodetachment (a-EPD) tandem mass spectrometry to characterize LPS and LOS from two crucial players in the human gut microbiota, Escherichia coli Nissle and Bacteroides fragilis. a-EPD is a hybrid activation method that uses ultraviolet photoirradiation to generate charge-reduced radical ions followed by collisional activation to produce informative fragmentation patterns. We benchmark the a-EPD method for top-down characterization of triacyl LOS from E. coli R2, then focus on characterization of LPS from E. coli Nissle and B. fragilis. Notably, a-EPD affords extensive fragmentation throughout the backbone of the core OS and O-antigen regions of LPS from E. coli Nissle. This hybrid approach facilitated the elucidation of structural details for LPS from B. fragilis, revealing a putative hexuronic acid (HexA) conjugated to lipid A.

Layer-by-layer coated probiotics with chitosan and liposomes exhibit enhanced therapeutic effects for DSS-induced colitis in mice

Probiotic therapy has emerged as a promising approach for the treatment of gastrointestinal diseases, offering advantages in terms of safety and convenience. However, oral probiotics encounter significant challenges, including exposure to a hostile gastric environment with low pH, bile salts, elevated levels of reactive oxygen species (ROS), and damage to the protective mucus layer. These factors reduce probiotic survival rates and limit their physiological activity. To address these challenges, we developed a layer-by-layer coated probiotics with curcumin-loaded liposome and polymer. Through DSS-induced colitis mice experiments, we demonstrated that the coated probiotics exhibited an improved survival rate in the gastrointestinal tract and enhanced adhesion to the intestinal mucosa. Furthermore, multi-layered coated probiotics exhibited remarkable efficacy in alleviating colitis by efficiently repairing the gut barrier, modulating gut microbial homeostasis, and reducing bacterial motility at sites of colonic inflammation. Our innovative approach holds promise for effectively treating gastrointestinal diseases.

Polyphenolic Nanoparticle-Modified Probiotics for Microenvironment Remodeling and Targeted Therapy of Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) refer to multifaceted disorders in the intestinal microenvironment and microbiota homeostasis. In view of the broad bioactivity and high compatibility of polyphenols, there is considerable interest in developing a polyphenol-based collaborative platform to remodel the IBD microenvironment and regulate microbiota. Here, we demonstrated the coordination assembly of nanostructured polyphenols to modify probiotics and simultaneously deliver drugs for IBD treatment. Inspired by the distinctive structure of tannic acid (TA), we fabricated nanostructured pBDT-TA by using a self-polymerizable aromatic dithiol (BDT) and TA, which exhibited excellent antioxidant and anti-inflammatory capability in vitro. We thus coated pBDT-TA and sodium alginate (SA) to the surface of Escherichia coli Nissle 1917 layer by layer to construct the collaborative platform EcN@SA-pBDT-TA. The modified probiotics showed improved resistance to oxidative and inflammatory stress, which resulted in superior colon accumulation and retention in IBD model mice. Further, EcN@SA-pBDT-TA could alleviate dextran sulfate sodium (DSS)-induced colitis by controlling the inflammatory response, repairing intestinal barriers, and modulating gut microbiota. Importantly, EcN@SA-pBDT-TA-mediated IBD drug delivery could achieve an improved therapeutic effect in DSS model mice. Given the availability and functionality of polyphenol and prebiotics, we expected that nanostructured polyphenol-modified probiotics provided a solution to develop a collaborative platform for IBD treatment.

The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Comparative analysis of biofilm characterization of probiotic Escherichia coli

Biofilms are thought to play a vital role in the beneficial effects of probiotic bacteria. However, the structure and function of probiotic biofilms are poorly understood. In this work, biofilms of Escherichia coli (E. coli) Nissle 1917 were investigated and compared with those of pathogenic and opportunistic strains (E. coli MG1655, O157:H7) using crystal violet assay, confocal laser scanning microscopy, scanning electron microscopy and FTIR microspectroscopy. The study revealed significant differences in the morphological structure, chemical composition, and spatial heterogeneity of the biofilm formed by the probiotic E. coli strain. In particular, the probiotic biofilm can secrete unique phospholipid components into the extracellular matrix. These findings provide new information on the morphology, architecture and chemical heterogeneity of probiotic biofilms. This information may help us to understand the beneficial effects of probiotics for various applications.

Letter: The multifaceted role of Escherichia coli in influencing disorders of industrial populations

This article is linked to Faqerah et al papers. To view these articles, visit https://doi.org/10.1111/apt.17720 and https://doi.org/10.1111/apt.17883

Layer-by-layer coated probiotics with chitosan and liposomes demonstrate improved stability and antioxidant properties in vitro

Probiotics are of increasing interest for their potential health benefits, but their survival and adhesion in the harsh gastrointestinal environment remain a concern. This study explored a single-cell encapsulation technique to enhance probiotic survival and adhesion in the gastrointestinal tract. We encapsulated probiotics in curcumin-loaded liposomes, further coated them with polymers using layer-by-layer techniques. The coated probiotics were evaluated for survival in simulated gastrointestinal conditions, adhesion to colonic mucus, and scavenging of reactive oxygen species (ROS). The results showed that multi-layer encapsulation increased probiotic size at the nanoscale, enhancing their survival in simulated gastrointestinal conditions. Upon reaching the colon, the shedding of the coating coincided with probiotic proliferation. Additionally, the coated probiotics exhibited increased adhesion to colonic mucus. Moreover, the coating acted as a protective barrier for effectively scavenging reactive oxygen radicals, ensuring probiotic survival in inflammatory environments. This study combines the synergistic effects of probiotics and curcumin, underscoring the promise of single-cell encapsulation techniques in improving the efficacy of probiotics for addressing colitis-related diseases.

Microfluidics-Derived Microparticles with Prebiotics and Probiotics for Enhanced In Situ Colonization and Immunoregulation of Colitis

Oral administration of probiotics orchestrates the balance between intestinal microbes and the immune response. However, effective delivery and in situ colonization are limited by the harsh environment of the gastrointestinal tract. Herein, we provide a microfluidics-derived encapsulation strategy to address this problem. A novel synergistic delivery system composed of EcN Nissle 1917 and prebiotics, including alginate sodium and inulin gel, for treating inflammatory bowel disease and colitis-associated colorectal cancer is proposed. We demonstrated that EcN@AN microparticles yielded promising gastrointestinal resistance for on-demand probiotic delivery and colon-retentive capability. EcN@AN microparticles efficiently ameliorated intestinal inflammation and modulated the gut microbiome in experimental colitis. Moreover, the prebiotic composition of EcN@AN enhanced the fermentation of relative short-chain fatty acid metabolites, a kind of postbiotics, to exert anti-inflammatory and tumor-suppressive effects in murine models. This microfluidcis-based approach for the coordinated delivery of probiotics and prebiotics may have broad implications for gastrointestinal bacteriotherapy applications.

The Potential Impact of Probiotics on Human Health: An Update on Their Health-Promoting Properties

Probiotics, known to be live microorganisms, have been shown to improve or restore the gut microbiota, which in turn has been linked to improved health. It is believed that probiotics are the modern equivalent of a panacea, with claims that they may treat or prevent different diseases both in children and adults (e.g., from colic in babies to cardiovascular disease, respiratory infection, and cancer in adults). Ever since the early 2000s, probiotic-based fermented foods have had a resurgence in popularity, mostly due to claims made regarding their health benefits. Fermented foods have been associated with the prevention of irritable bowel syndrome, lactose intolerance, gastroenteritis, and obesity, but also other conditions such as chronic diarrhea, allergies, dermatitis, and bacterial and viral infections, all of which are closely related to an unhealthy lifestyle. Recent and ongoing developments in microbiome/microbiota science have given us new research directions for probiotics. The new types, mechanisms, and applications studied so far, and those currently under study, have a great potential to change scientific understanding of probiotics' nutritional applications and human health care. The expansion of fields related to the study of the microbiome and the involvement of probiotics in its improvement foreshadow an era of significant changes. An expanding range of candidate probiotic species is emerging that can address newly elucidated data-driven microbial niches and host targets. In the probiotic field, new variants of microbiome-modulating interventions are being developed, including prebiotics, symbiotics, postbiotics, microbial consortia, live biotherapeutic products, and genetically modified organisms, with renewed interest in polyphenols, fibers, and fermented foods to ensure human health. This manuscript aims to analyze recent, emerging, and anticipated trends in probiotics (sources, doses, mechanism of action, diseases for which probiotics are administered, side effects, and risks) and create a vision for the development of related areas of influence in the field.

The single-cell modification strategies for probiotics delivery in inflammatory bowel disease: A review

Oral probiotic therapy has become an increasingly attractive method for treating various diseases, including intestinal barrier dysfunction, inflammatory bowel disease (IBD), and colorectal cancer due to its safety and convenience. However, only a few probiotics after oral gavage can survive the acidic and bile salt conditions of the gastrointestinal tract and colonize the colon to have a nutritional effect on the host. To address these challenges, encapsulation technology has been applied to protect probiotics from harsh gastrointestinal conditions, improve gut adhesion, and reduce immunogenicity. In addition, some of the functional polysaccharides are used to endow probiotics with exogenous functions as prebiotics. In this review, we systematically introduced the advancements of emerging single-cell modification strategies for probiotics in IBD applications. Additionally, we discussed the limitations and perspectives of single-cell modification strategies for probiotics. This review contributed to the development of probiotic delivery systems with higher therapeutic efficacy against colitis.

Expectations for employing Escherichia coli Nissle 1917 in food science and nutrition

As a promising probiotic strain, Escherichia coli Nissle 1917 (EcN) has been demonstrated to confer beneficial effects on intestinal health, immune function, and pathogen prevention. Additionally, EcN has also been widely studied due to its clear genomic information, tractable gene regulation, and simple growth conditions. This review summarizes the various applications potential of EcN in food science and nutrition, including inflammation prevention, tumor-targeting therapy, antibacterial agents for food, and nutrient production with a focus on specific case studies. Moreover, we highlight the major challenges of employing EcN in food science and nutrition, including regulatory approval, stability during food processing, and consumer acceptance. Finally, we conclude with a discussion on perspectives related to employing EcN in food science and nutrition.

Targeting DSS-induced ulcerative colitis: evaluating the therapeutic potential of WPI-stachyose conjugates

The pursuit of food-based alternatives to conventional therapies for ulcerative colitis (UC) demands immediate attention. In prior investigations, we synthesized WPI-stachyose conjugates through the Maillard reaction, identifying them as functional prebiotics. However, their impact on in vivo regulation of gut microbiota remains inadequately explored. To bridge this gap, we delved into the therapeutic effects and mechanisms of WPI-stachyose conjugates as prebiotic-functional components in C57BL/6J mice afflicted with dextran sodium sulfate (DSS)-induced UC. The treatment involving WPI-stachyose conjugates led to significant therapeutic advancements, evident in the reduction of pro-inflammatory cytokine levels and restoration of gut microbiota composition. Noticeable enhancements were observed in UC-associated symptoms, including weight loss, colon length reduction, and tissue damage, notably improving in the treated mice. Remarkably, both the conjugates and the physical combination effectively lowered pro-inflammatory cytokines and oxidative stress, with the conjugates demonstrating enhanced effectiveness. Furthermore, the simultaneous administration of WPI-stachyose conjugates further amplified the presence of beneficial bacteria and elevated short-chain fatty acids, acknowledged for their favorable impact across various conditions. These findings underscore the potential therapeutic application of WPI-stachyose conjugates in addressing DSS-induced UC, offering insights into innovative therapeutic strategies.

Benefits and concerns of probiotics: an overview of the potential genotoxicity of the colibactin-producing Escherichia coli Nissle 1917 strain

Recently, the mounting integration of probiotics into human health strategies has gathered considerable attention. Although the benefits of probiotics have been widely recognized in patients with gastrointestinal disorders, immune system modulation, and chronic-degenerative diseases, there is a growing need to evaluate their potential risks. In this context, new concerns have arisen regarding the safety of probiotics as some strains may have adverse effects in humans. Among these strains, Escherichia coli Nissle 1917 (EcN) exhibited traits of concern due to a pathogenic locus in its genome that produces potentially genotoxic metabolites. As the use of probiotics for therapeutic purposes is increasing, the effects of potentially harmful probiotics must be carefully evaluated. To this end, in this narrative review article, we reported the findings of the most relevant in vitro and in vivo studies investigating the expanding applications of probiotics and their impact on human well-being addressing concerns arising from the presence of antibiotic resistance and pathogenic elements, with a focus on the polyketide synthase (pks) pathogenic island of EcN. In this context, the literature data here discussed encourages a thorough profiling of probiotics to identify potential harmful elements as done for EcN where potential genotoxic effects of colibactin, a secondary metabolite, were observed. Specifically, while some studies suggest EcN is safe for gastrointestinal health, conflicting findings highlight the need for further research to clarify its safety and optimize its use in therapy. Overall, the data here presented suggest that a comprehensive assessment of the evolving landscape of probiotics is essential to make evidence-based decisions and ensure their correct use in humans.

Preparation of Polysaccharide-Protein Hydrogels with an Ultrafast Self-Healing Property as a Superior Oral Delivery System of Probiotics

Oral administration of probiotic supplements can effectively regulate intestinal disorders. However, harsh gastrointestinal conditions greatly limit the bioavailability of probiotics. In this work, biomass-derived polysaccharide-protein hydrogels (Dex-sBSA hydrogels) were constructed as an oral probiotic delivery system. The hydrogel encapsulation significantly promoted the growth and proliferation of probiotics and protected them from gastric acid, bile salts, reactive oxygen species, and antibiotics. In vivo experiments demonstrated that the hydrogel encapsulation significantly enhanced the bioavailability of probiotics, of which the cell number in the intestine, colon, and cecum was 35 times, 8 times, and 203 times higher than the free one, respectively. Attributed to the superior ultrafast self-healing property, the Dex-sBSA hydrogel successfully prevented the probiotics from quick elimination and prolonged the retention time in the gut, providing great possibilities for colonization and proliferation. These results clearly indicate the great potential of the Dex-sBSA hydrogel as a superior oral delivery system for probiotics.

Comprehensive probiogenomics analysis of the commensal Escherichia coli CEC15 as a potential probiotic strain

BACKGROUND

Probiotics have gained attention for their potential maintaining gut and immune homeostasis. They have been found to confer protection against pathogen colonization, possess immunomodulatory effects, enhance gut barrier functionality, and mitigate inflammation. However, a thorough understanding of the unique mechanisms of effects triggered by individual strains is necessary to optimize their therapeutic efficacy. Probiogenomics, involving high-throughput techniques, can help identify uncharacterized strains and aid in the rational selection of new probiotics. This study evaluates the potential of the Escherichia coli CEC15 strain as a probiotic through in silico, in vitro, and in vivo analyses, comparing it to the well-known probiotic reference E. coli Nissle 1917. Genomic analysis was conducted to identify traits with potential beneficial activity and to assess the safety of each strain (genomic islands, bacteriocin production, antibiotic resistance, production of proteins involved in host homeostasis, and proteins with adhesive properties). In vitro studies assessed survival in gastrointestinal simulated conditions and adhesion to cultured human intestinal cells. Safety was evaluated in BALB/c mice, monitoring the impact of E. coli consumption on clinical signs, intestinal architecture, intestinal permeability, and fecal microbiota. Additionally, the protective effects of both strains were assessed in a murine model of 5-FU-induced mucositis.

RESULTS

CEC15 mitigates inflammation, reinforces intestinal barrier, and modulates intestinal microbiota. In silico analysis revealed fewer pathogenicity-related traits in CEC15, when compared to Nissle 1917, with fewer toxin-associated genes and no gene suggesting the production of colibactin (a genotoxic agent). Most predicted antibiotic-resistance genes were neither associated with actual resistance, nor with transposable elements. The genome of CEC15 strain encodes proteins related to stress tolerance and to adhesion, in line with its better survival during digestion and higher adhesion to intestinal cells, when compared to Nissle 1917. Moreover, CEC15 exhibited beneficial effects on mice and their intestinal microbiota, both in healthy animals and against 5FU-induced intestinal mucositis.

CONCLUSIONS

These findings suggest that the CEC15 strain holds promise as a probiotic, as it could modulate the intestinal microbiota, providing immunomodulatory and anti-inflammatory effects, and reinforcing the intestinal barrier. These findings may have implications for the treatment of gastrointestinal disorders, particularly some forms of diarrhea.

Armored probiotics for oral delivery

As a kind of intestinal flora regulator, probiotics show great potential in the treatment of many diseases. However, orally delivered probiotics are often vulnerable to unfriendly gastrointestinal environments, resulting in a low survival rate and decreased therapeutic efficacy. Decorating or encapsulating probiotics with functional biomaterials has become a facile yet useful strategy, and probiotics can be given different functions by wearing different armors. This review systematically discusses the challenges faced by oral probiotics and the research progress of armored probiotics delivery systems. We focus on how various functional armors help probiotics overcome different obstacles and achieve efficient delivery. We also introduce the applications of armor probiotics in disease treatment and analyze the future trends of developing advanced probiotics-based therapies.

The novel immunobiotic Clostridium butyricum S-45-5 displays broad-spectrum antiviral activity in vitro and in vivo by inducing immune modulation

Clostridium butyricum is known as a probiotic butyric acid bacterium that can improve the intestinal environment. In this study, we isolated a new strain of C. butyricum from infant feces and evaluated its physiological characteristics and antiviral efficacy by modulating the innate immune responses in vitro and in vivo. The isolated C. butyricum S-45-5 showed typical characteristics of C. butyricum including bile acid resistance, antibacterial ability, and growth promotion of various lactic acid bacteria. As an antiviral effect, C. butyricum S-45-5 markedly reduced the replication of influenza A virus (PR8), Newcastle Disease Virus (NDV), and Herpes Simplex Virus (HSV) in RAW264.7 cells in vitro. This suppression can be explained by the induction of antiviral state in cells by the induction of antiviral, IFN-related genes and secretion of IFNs and pro-inflammatory cytokines. In vivo, oral administration of C. butyricum S-45-5 exhibited prophylactic effects on BALB/c mice against fatal doses of highly pathogenic mouse-adapted influenza A subtypes (H1N1, H3N2, and H9N2). Before challenge with influenza virus, C. butyricum S-45-5-treated BALB/c mice showed increased levels of IFN-β, IFN-γ, IL-6, and IL-12 in serum, the small intestine, and bronchoalveolar lavage fluid (BALF), which correlated with observed prophylactic effects. Interestingly, after challenge with influenza virus, C. butyricum S-45-5-treated BALB/c mice showed reduced levels of pro-inflammatory cytokines and relatively higher levels of anti-inflammatory cytokines at day 7 post-infection. Taken together, these findings suggest that C. butyricum S-45-5 plays an antiviral role in vitro and in vivo by inducing an antiviral state and affects immune modulation to alleviate local and systemic inflammatory responses caused by influenza virus infection. Our study provides the beneficial effects of the new C. butyricum S-45-5 with antiviral effects as a probiotic.

Cell membrane nanomaterials composed of phospholipids and glycoproteins for drug delivery in inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is a serious chronic intestinal disorder with an increasing global incidence. However, current treatment strategies, such as anti-inflammatory drugs and probiotics, have limitations in terms of safety, stability, and effectiveness. The emergence of targeted nanoparticles has revolutionized IBD treatment by enhancing the biological properties of drugs and promoting efficiency and safety. Unlike synthetic nanoparticles, cell membrane nanomaterials (CMNs) consist primarily of biological macromolecules, including phospholipids, proteins, and sugars. CMNs include red blood cell membranes, macrophage membranes, and leukocyte membranes, which possess abundant glycoprotein receptors and ligands on their surfaces, allowing for the formation of cell-to-cell connections with other biological macromolecules. Consequently, they exhibit superior cell affinity, evade immune responses, and target inflammation effectively, making them ideal material for targeted delivery of IBD therapies. This review explores various CMNs delivery systems for IBD treatment. However, due to the complexity and harsh nature of the intestinal microenvironment, the lack of flexibility or loss of selectivity poses challenges in designing single CMNs delivery strategies. Therefore, we propose a hierarchically programmed delivery modality that combines CMNs with pH, charge, ROS and ligand-modified responsive nanoparticles. This approach significantly improves delivery efficiency and points the way for future research in this area.

Escherichia coli Nissle 1917 ghosts alleviate inflammatory bowel disease in zebrafish

Escherichia coli Nissle 1917 (EcN) has become a research hotspot in inflammatory bowel disease (IBD). It has a strong targeting effect on the colon, and has some therapeutic effect on inflammatory bowel disease. EcN is prepared into EcN ghosts, which also retain EcN's biological characteristics. Consequently, EcN ghosts are used for drug delivery. This study evaluated the safety and efficacy of EcN ghosts as carriers of drugs for treating IBD in zebrafish. Caco-2 cell adhesion experiments and zebrafish intestinal adhesion experiments demonstrated that EcN ghosts was highly adherent to the intestine. Additionally, oral administration of EcN ghosts attenuated dextran sulfate sodium-induced IBD symptoms by inhibiting neutrophil chemotaxis and reactive oxygen species production in larval zebrafish. Because of the unique biological functions of EcN ghosts, it may serve as a strategy for future targeted drug delivery in IBD treatment.

Targeting the Gut-Eye Axis: An Emerging Strategy to Face Ocular Diseases

The human microbiota refers to a large variety of microorganisms (bacteria, viruses, and fungi) that live in different human body sites, including the gut, oral cavity, skin, and eyes. In particular, the presence of an ocular surface microbiota with a crucial role in maintaining ocular surface homeostasis by preventing colonization from pathogen species has been recently demonstrated. Moreover, recent studies underline a potential association between gut microbiota (GM) and ocular health. In this respect, some evidence supports the existence of a gut-eye axis involved in the pathogenesis of several ocular diseases, including age-related macular degeneration, uveitis, diabetic retinopathy, dry eye, and glaucoma. Therefore, understanding the link between the GM and these ocular disorders might be useful for the development of new therapeutic approaches, such as probiotics, prebiotics, symbiotics, or faecal microbiota transplantation through which the GM could be modulated, thus allowing better management of these diseases.

Colibactin-induced genotoxicity and colorectal cancer exacerbation critically depends on adhesin-mediated epithelial binding

Various bacteria are suggested to contribute to colorectal cancer (CRC) development, including pks+ E. coli which produce the genotoxin colibactin that induces characteristic mutational signatures in host epithelial cells. It remains unclear how the highly unstable colibactin molecule is able to access host epithelial cells and its DNA to cause harm. Using the microbiota-dependent ZEB2-transgenic mouse model of invasive CRC, we found that pks+ E. coli drives CRC exacerbation and tissue invasion in a colibactin-dependent manner. Using isogenic mutant strains, we further demonstrate that CRC exacerbation critically depends on expression of the E. coli type-1 pilus adhesin FimH and the F9-pilus adhesin FmlH. Blocking bacterial adhesion using a pharmacological FimH inhibitor attenuates colibactin-mediated genotoxicity and CRC exacerbation. Together, we show that the oncogenic potential of pks+ E. coli critically depends on bacterial adhesion to host epithelial cells and is critically mediated by specific bacterial adhesins. Adhesin-mediated epithelial binding subsequently allows production of the genotoxin colibactin in close proximity to host epithelial cells, which promotes DNA damage and drives CRC development. These findings present promising therapeutic avenues for the development of anti-adhesive therapies aiming at mitigating colibactin-induced DNA damage and inhibiting the initiation and progression of CRC, particularly in individuals at risk for developing CRC.

Mechanisms and regulation of defensins in host defense

As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.

Harnessing the potential of probiotics in the treatment of alcoholic liver disorders

In the current scenario, prolonged consumption of alcohol across the globe is upsurging an appreciable number of patients with the risk of alcohol-associated liver diseases. According to the recent report, the gut-liver axis is crucial in the progression of alcohol-induced liver diseases, including steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Despite several factors associated with alcoholic liver diseases, the complexity of the gut microflora and its great interaction with the liver have become a fascinating area for researchers due to the high exposure of the liver to free radicals, bacterial endotoxins, lipopolysaccharides, inflammatory markers, etc. Undoubtedly, alcohol-induced gut microbiota imbalance stimulates dysbiosis, disrupts the intestinal barrier function, and trigger immune as well as inflammatory responses which further aggravate hepatic injury. Since currently available drugs to mitigate liver disorders have significant side effects, hence, probiotics have been widely researched to alleviate alcohol-associated liver diseases and to improve liver health. A broad range of probiotic bacteria like Lactobacillus, Bifidobacteria, Escherichia coli, Sacchromyces, and Lactococcus are used to reduce or halt the progression of alcohol-associated liver diseases. Several underlying mechanisms, including alteration of the gut microbiome, modulation of intestinal barrier function and immune response, reduction in the level of endotoxins, and bacterial translocation, have been implicated through which probiotics can effectively suppress the occurrence of alcohol-induced liver disorders. This review addresses the therapeutic applications of probiotics in the treatment of alcohol-associated liver diseases. Novel insights into the mechanisms by which probiotics prevent alcohol-associated liver diseases have also been elaborated.

Probiotic Escherichia coli Nissle 1917 propelled micro-robot with pH sensitivity for hypoxia targeted intestinal tumor therapy

Poor drug penetration in hypoxia area of solid tumor is a big challenge for intestinal tumor therapy and thus it is crucial to develop an effective strategy to overcome this challenge. Compared with other bacteria used for construction of hypoxia targeted bacteria micro-robot, the Escherichia coli Nissle 1917 (EcN) bacteria are nonpathogenic Gram-negative probiotic and can especially target and identify the signal molecules in the hypoxic region of tumor, and thus, in this study, we choose EcN to construct a bacteria propelled micro-robot for targeting intestinal tumor therapy. Firstly, the MSNs@DOX with average diameter of 200 nm were synthesized and conjugated with EcN bacteria using EDC/NHS chemical crosslinking method to construct a EcN propelled micro-robot. The motility of micro-robot was then evaluated and the motion velocity of EcN-pMSNs@DOX was 3.78 µm/s. Compared with pMSNs@DOX without EcN driven, EcN bacteria propelled micro-robot transported much more pMSNs@DOX into the inner of HCT-116 3D multicellular tumor spheroids. However, the EcN bacteria are non-intracelluar bacteria which lead to the micro-robot can not directly enter into tumor cells. Therefore, we utilized acid-labile linkers of cis-aconitic amido bone to link EcN with MSNs@DOX nanoparticles to achieve the pH sensitive separation of EcN with MSNs@DOX from the micro-robot. At 4 h of incubation, the isolated MSNs@DOX began to enter into the tumor cells through CLSM observation. In vitro live/dead staining results show that EcN-pMSNs@DOX induced much more cell death than pMSNs@DOX at 24 and 48 h of incubation with HCT-116 tumor cells in acid culture media (pH 5.3). For the validation of the therapeutic efficacy of the micro-robot for intestinal tumor, we established the HCT-116 subcutaneous transplantation tumor model. After 28 days of treatment, EcN-pMSNs@DOX dramatically inhibit tumor growth with tumor volume was around 689 mm³, induce much more tumor tissues necrosis and apoptosis. Finally, the toxicity of this micro-robot was investigated by pathological analysis the liver and heart tissues. We expect that the pH sensitive EcN propelled micro-robot here we constructed may be a safe and feasible strategy for intestinal tumor therapy.

Anti-Inflammatory, Barrier Maintenance, and Gut Microbiome Modulation Effects of Saccharomyces cerevisiae QHNLD8L1 on DSS-Induced Ulcerative Colitis in Mice

The use of probiotics has been considered as a new therapy option for ulcerative colitis (UC), and yeast has recently received widespread recommendation for human health. In this study, the probiotic characteristics of four yeast strains, Saccharomyces boulardii CNCMI-745, Kluyveromyces marxianus QHBYC4L2, Saccharomyces cerevisiae QHNLD8L1, and Debaryomyces hansenii QSCLS6L3, were evaluated in vitro; their ability to ameliorate dextran sulfate sodium (DSS)-induced colitis was investigated. Among these, S. cerevisiae QHNLD8L1 protected against colitis, which was reflected by increased body weight, colon length, histological injury relief, decreased gut inflammation markers, and intestinal barrier restoration. The abundance of the pathogenic bacteria Escherichia–Shigella and Enterococcaceae in mice with colitis decreased after S. cerevisiae QHNLD8L1 treatment. Moreover, S. cerevisiae QHNLD8L1 enriched beneficial bacteria Lactobacillus, Faecalibaculum, and Butyricimonas, enhanced carbon metabolism and fatty acid biosynthesis function, and increased short chain fatty acid (SCFAs) production. Taken together, our results indicate the great potential of S. cerevisiae QHNLD8L1 supplementation for the prevention and alleviation of UC.

Advances in Escherichia coli Nissle 1917 as a customizable drug delivery system for disease treatment and diagnosis strategies

With the in-depth and comprehensive study of bacteria and their related ecosystems in the human body, bacterial-based drug delivery system has become an emerging biomimetic platform that can retain the innate biological functions. Benefiting from its good biocompatibility and ideal targeting ability as a biological carrier, Escherichia coli Nissle 1917 (ECN) has been focused on the treatment strategies of inflammatory bowel disease and tumor. The advantage of a bacterial carrier is that it can express exogenous protein while also acting as a natural capsule by releasing drug slowly as a result of its own colonization impact. In order to survive in harsh environments such as the digestive tract and tumor microenvironment, ECN can be modified or genetically engineered to enhance its function and host adaptability. The adoption of ECN carries or expresses drugs which are essential for accurate diagnosis and treatment. This review briefly describes the properties of ECN, the relationship between ECN and inflammation and tumor, and the strategy of using surface modification and genetic engineering to modify ECN as a delivery carrier for disease treatment.

Delivery of E. coli Nissle to the mouse gut by mucoadhesive microcontainers does not improve its competitive ability against strains linked to ulcerative colitis

For patients with ulcerative colitis (UC), administration of the probiotic E. coli Nissle (EcN) holds promise for alleviation of disease symptoms. The mechanisms are unclear, but it has been hypothesised that a capacity of the probiotic to outcompete potentially detrimental UC-associated E. coli strains plays an important role. However, this could previously not be confirmed in a mouse model of competition between EcN and two UC-associated strains, as reported by Petersen et al. 2011. In the present study, we re-evaluated the idea, hypothesising that delivery of EcN by a micro device dosing system (microcontainers), designed for delivery into the intestinal mucus, could support colonisation and confer a competition advantage compared to classical oral dosing. Six groups of mice were pre-colonised with one of two UC-associated E. coli strains followed by oral delivery of EcN, either in capsules containing microcontainers with freeze-dried EcN powder, capsules containing freeze-dried EcN powder, or as a fresh sucrose suspension. Co-colonisation between the probiotic and the disease-associated strains was observed regardless of dosing method, and no competition advantages linked to microcontainer delivery were identified within this setup. Other approaches are thus needed if the competitive capacity of EcN in the gut should be improved.

Role of adherent invasive Escherichia coli in pathogenesis of inflammatory bowel disease

Gut microbiota imbalances play an important role in inflammatory bowel disease (IBD), but no single pathogenic microorganism critical to IBD that is specific to the IBD terminal ileum mucosa or can invade intestinal epithelial cells has been found. Invasive Escherichia coli (E. coli) adhesion to macrophages is considered to be closely related to the pathogenesis of inflammatory bowel disease. Further study of the specific biological characteristics of adherent invasive E. coli (AIEC) may contribute to a further understanding of IBD pathogenesis. This review explores the relationship between AIEC and the intestinal immune system, discusses the prevalence and relevance of AIEC in Crohn's disease and ulcerative colitis patients, and describes the relationship between AIEC and the disease site, activity, and postoperative recurrence. Finally, we highlight potential therapeutic strategies to attenuate AIEC colonization in the intestinal mucosa, including the use of phage therapy, antibiotics, and anti-adhesion molecules. These strategies may open up new avenues for the prevention and treatment of IBD in the future.

Stronger gut microbiome modulatory effects by postbiotics than probiotics in a mouse colitis model

Probiotics are increasingly used as adjunctive therapy to manage gastrointestinal diseases, such as ulcerative colitis. However, probiotic use has posed some safety concerns. Thus, postbiotics are proposed as alternatives to probiotics in clinical applications. However, no study has directly compared the clinical benefits of probiotics and postbiotics. This study compared the beneficial effect of postbiotics and probiotics derived from the strain, Bifidobacterium adolescentis B8598, in a dextran sulfate sodium (DSS)-induced experimental colitis mouse model. Four groups of mice (n = 7 per group) were included in this work: Control (received water plus saline), DSS (received DSS without postbiotic/probiotic), Postbiotic (received DSS plus postbiotic), and Probiotic (received DSS plus probiotic). Our results showed that intragastric administration of both probiotic and postbiotic ameliorated colitis, reflected by decreased histology scores in Postbiotic and Probiotic groups compared with DSS group (P < 0.05). The fecal microbiota alpha diversity was not significantly affected by DSS-, postbiotic, or probiotic treatment. However, the postbiotic treatment showed stronger effects on modulating the fecal microbiota beta diversity, composition, and metagenomic potential than the probiotic treatment. Overall, our findings suggested that probiotics and postbiotics had similar ability to improve disease phenotype but had distinct ability to regulate the gut microbiota and metabolic pathways in the context of ulcerative colitis. In view of the smaller safety concern of postbiotics compared with probiotics and its stronger modulatory effect on the host gut microbiota, we propose that postbiotics are to be considered for use as next-generation biotherapeutics in managing ulcerative colitis or even other diseases.

The effect of Escherichia coli ŽP strain with a conjugation-based colicin E7 delivery on growth performance, hematological, biochemical, and histological parameters, gut microbiota, and nonspecific immunity of broilers

The Escherichia coli ŽP strain (ŽP) was constructed based on the known probiotic E. coli strain Nissle 1917. It was genetically modified to carry the colicin E7 synthesis gene encoding DNase on a conjugative plasmid and the colicin E7 immunity gene in the chromosome. The aim of this study was to evaluate the effects of the daily ŽP per oral administration (5 × 10⁸ or 5 × 10¹⁰ CFU per bird) on the growth performance, hematological, biochemical, histological parameters, gut microbiota, and nonspecific immunity of the 4-24 days old broilers. The ŽP administration increased the abundance of genera Bacillus, Butyrivibrio, and Clostridium and did not influence the weight gain of 4-16 days old broilers. The biochemical parameters were within normal ranges for poultry in experimental and control groups. The ŽP administration had no effect on the erythrocyte numbers, hemoglobin and immunoglobulin Y concentrations, but significantly increased the serum lysozyme concentration, leukocyte numbers, and reactive oxygen species production by phagocytes compared with the control group. It did not cause inflammatory changes in intestinal mucosa, Peyer's patches, and spleen. Thus, the ŽP had no detrimental effects on broiler health and could be an efficient probiotic for the broiler colibacillosis prophylaxis.

Opportunities and challenges for synthetic biology in the therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex, chronic intestinal inflammatory disorder that primarily includes Crohn’s disease (CD) and ulcerative colitis (UC). Although traditional antibiotics and immunosuppressants are known as the most effective and commonly used treatments, some limitations may be expected, such as limited efficacy in a small number of patients and gut flora disruption. A great many research studies have been done with respect to the etiology of IBD, while the composition of the gut microbiota is suggested as one of the most influential factors. Along with the development of synthetic biology and the continuing clarification of IBD etiology, broader prospects for novel approaches to IBD therapy could be obtained. This study presents an overview of the currently existing treatment options and possible therapeutic targets at the preclinical stage with respect to microbial synthesis technology in biological therapy. This study is highly correlated to the following topics: microbiota-derived metabolites, microRNAs, cell therapy, calreticulin, live biotherapeutic products (LBP), fecal microbiota transplantation (FMT), bacteriophages, engineered bacteria, and their functional secreted synthetic products for IBD medical implementation. Considering microorganisms as the main therapeutic component, as a result, the related clinical trial stability, effectiveness, and safety analysis may be the major challenges for upcoming research. This article strives to provide pharmaceutical researchers and developers with the most up-to-date information for adjuvant medicinal therapies based on synthetic biology.