Microencapsulation of probiotics for gastrointestinal delivery

Sodium alginate/low methoxyl pectin composite hydrogel beads prepared via gas-shearing technology for enhancing the colon-targeted delivery of probiotics and modulating gut microbiota

The probiotic encapsulation system has the potential to enhance the prebiotic effects of probiotics. However, challenges arise from the release behavior of this system in vivo and the large size of hydrogel beads. This study aims to address the issues related to the size of previous hydrogel beads and assess the colon-targeted delivery of probiotic polysaccharides composite hydrogel beads (PPHB). PPHB prepared by gas-shearing technique significantly reduced the average particle size and demonstrated a high protective capacity for probiotics (after simulating intestinal conditions for 4 h, the viability of encapsulated probiotics remained at 107 CFU/g). The use of indocyanine green along with near-infrared-II in vivo imaging technology demonstrated the colon-targeted delivery of PPHB in vivo, which also extended the retention time of probiotics in the cecum and colon. Additionally, the colon-targeted delivery of PPHB was also demonstrated by dietary supplementation in vivo. PPHB significantly enhanced the diversity and richness of intestinal microflora species, increased the levels of short-chain fatty acids, raised the relative abundance of beneficial bacteria, and significantly decreased the relative abundance of harmful bacteria. Alginate-based PPHB is more suitable for encapsulating functional ingredients for colon-targeted delivery and modulating gut microbiota.

Microfluidic design and preparation of hydrogel microcapsules of Mesona chinensis polysaccharide: Characterization, pH-responsive behavior and gastrointestinal protection for Lactobacillus plantarum

Probiotics have brought many health benefits to the human body. However, their viability during gastrointestinal transit is a concern. Therefore, this study selected Mesona chinensis polysaccharide (MCP), an edible natural polysaccharide, and constructed a new type of microcapsules using MCP as raw material to prepare cross-linked calcium ions through a microfluidic system as an ideal intestinal targeting carrier to achieve precise delivery of bioactive substances. The results showed that the Mesona chinensis polysaccharide microcapsules (MCM) had high monodispersity, stable morphology and uniform particle size (737.25 ± 10.40-511.65 ± 10.99 μm) under various parameters, and had good pH-response ability in simulated body fluids. In vivo imaging demonstrated the targeting and protective effects of the microcapsules. Compared to the free group, MCM had a longer retention time in the intestine. After encapsulating Lactobacillus plantarum, MCM formed a dense protective layer on the outer layer in simulated gastric fluid, which improved the survival and storage stability of Lactobacillus plantarum. It can be reasonably proposed that MCM represents a viable alternative as a carrier with gastric acid protection and intestinal targeting. This has the potential to expand the application of MCP in functional food and medicine, while also facilitating the future delivery of bioactive substances.

Enhancing Viability of Lactobacillus rhamnosus GG and Total Polyphenol Content in Fermented Black Goji Berry Beverage Through Calcium-Alginate Encapsulation with Hydrocolloids

Encapsulation techniques play a crucial role in enhancing the stability and viability of probiotics in functional foods. This study investigates the efficacy of calcium-alginate encapsulation, combined with hydrocolloids such as carrageenan, agar, and gelatin, in improving the survival of Lactobacillus rhamnosus GG (LGG) and stabilizing the total phenolic content (TPC) in fermented black goji berry beverages. The results revealed that 1.5% alginate encapsulation, combined with 1% carrageenan, agar, or gelatin and 5% calcium, significantly enhanced the LGG viability and increased the TPC content in the fermented black goji berry beads when compared to calcium-alginate encapsulation alone. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the successful incorporation and interaction of hydrocolloids within the encapsulation matrix. Among the formulations, calcium-alginate-gelatin beads exhibited the highest LGG survival rates after simulated gastric and intestinal digestion. Notably, calcium-alginate beads containing carrageenan preserved LGG viability during simulated gastric and intestinal conditions when co-digested with all tested milk types (high carbohydrate, high protein, and high fat). Co-ingestion with these milk types further improved TPC retention in all bead formulations, as the macronutrients in milk provided protective effects, stabilizing the encapsulated polyphenols and minimizing their degradation during simulated gastric and intestinal digestion. This study highlights the potential of calcium-alginate encapsulation, integrated with hydrocolloids such as carrageenan, agar, or gelatin, to improve probiotic viability and polyphenol stability, offering promising applications for enhancing the functional properties of non-dairy fermented beverages.

Microencapsulation of Probiotics for Enhanced Stability and Health Benefits in Dairy Functional Foods: A Focus on Pasta Filata Cheese

Probiotics provide significant health benefits, but their viability is often compromised during production, storage, and passage through the gastrointestinal tract. These challenges hinder their effective incorporation into functional applications, particularly in dairy functional foods, in which factors such as acidity, oxygen exposure, and storage conditions negatively impact cell survival. The focus was on functional dairy foods, particularly on pasta filata cheeses. Indeed, the use of probiotics in pasta filata cheeses presents significant challenges due to the specific manufacturing processes, which encompass the application of high temperatures and other harsh conditions. These factors can adversely affect the viability and availability of probiotic microorganisms. However, microencapsulation has emerged as a promising solution, offering a protective barrier that enhances probiotic stability, improves survival rates, and facilitates targeted release in the gastrointestinal environment. This review examines the pivotal role of microencapsulation in stabilising probiotics for functional applications, emphasising its relevance in high-value food systems. Functional applications, including foods designed to offer essential nutritional benefits and promote host health, play a crucial role in disease prevention and immune system support, reducing the risk of infections and other physiological impairments. Key microencapsulation technologies are analysed, focusing on their benefits, limitations, and challenges related to scalability and industrial implementation. Additionally, this review discusses strategies to optimise formulations, ensure the sensory quality of final products, and explore future opportunities for expanding innovative applications that align with growing consumer demand for health-promoting solutions.

Delivery of Probiotic-Loaded Microcapsules in the Gastrointestinal Tract: A Review

Probiotics are live microorganisms that inhabit the gastrointestinal tract and confer health benefits to consumers. However, a sufficient number of viable probiotic cells must be delivered to the specific site of interest in the gastrointestinal tract to exert these benefits. Enhanced viability and tolerance to sublethal gastrointestinal stress can be achieved using appropriate coating materials and food matrices for orally consumed probiotics. The release mechanism and interaction of probiotic microcapsules with the gastrointestinal tract have been minimally explored in the literature to date. To the authors' knowledge, no review has been published to discuss the nature of release and the challenges in the targeted delivery of probiotics. This review addresses gastrointestinal-related complications in the formulation of targeted delivery and controlled release of probiotic strains. It investigates the impacts of environmental stresses during the transition stage and delivery to the target region in the gastrointestinal tract. The influence of factors such as pH levels, enzymatic degradation, and redox conditions on the release mechanisms of probiotics is presented. Finally, the available methods to evaluate the efficiency of a probiotic delivery system, including in vitro and in vivo, are reviewed and assessed. The paper concludes with a discussion highlighting the emerging technologies in the field and emphasising key areas in need of future study.

Navigating a challenging path: precision disease treatment with tailored oral nano-armor-probiotics

Oral probiotics have significant potential for preventing and treating many diseases. Yet, their efficacy is often hindered by challenges related to survival and colonization within the gastrointestinal tract. Nanoparticles emerge as a transformative solution, offering robust protection and enhancing the stability and bioavailability of these probiotics. This review explores the innovative application of nanoparticle-armored engineered probiotics for precise disease treatment, specifically addressing the physiological barriers associated with oral administration. A comprehensive evaluation of various nano-armor probiotics and encapsulation methods is provided, carefully analyzing their respective merits and limitations, alongside strategies to enhance probiotic survival and achieve targeted delivery and colonization within the gastrointestinal tract. Furthermore, the review explores the potential clinical applications of nano-armored probiotics in precision therapeutics, critically addressing safety and regulatory considerations, and proposing the innovative concept of 'probiotic intestinal colonization with nano armor' for brain-targeted therapies. Ultimately, this review aspires to guide the advancement of nano-armored probiotic therapies, driving progress in precision medicine and paving the way for groundbreaking treatment modalities.

Simultaneous Encapsulation of Probiotic Bacteria (Lactococcus lactis, and Lactiplantibacillus plantarum) in Calcium Alginate Hydrogels

Encapsulation in alginate hydrogel microspheres is an effective method for protecting and improving the survival of lactic acid bacteria in different environments. This research aims to expand the knowledge about the structure/property relationship of calcium alginate microspheres loaded with a mixture of autochthonous probiotic bacteria (Lactococcus lactis and Lactiplantibacillus plantarum). A novel hydrogel formulation (FORMLAB) was prepared by ionic gelation and the molecular interactions between the FORMLAB constituents, surface morphology, structure, swelling degree, and release profile were characterized. The simultaneous encapsulation of two bacterial cultures in the same compartment does not diminish their viability. The binding of calcium ions to bacterial cells creates favorable conditions for the propagation of the encapsulated bacteria. The molecular interactions between the FORMLAB constituents are complex, involving mainly hydrogen bonds and electrostatic interactions. With a very high degree of swelling followed by low crosslinking, the surface of the microspheres covered with bacterial cells and diffusion through the hydrogel matrix allow for the delivery of probiotics at the right time. The findings suggest that bacterial cells are efficiently delivered from calcium alginate microspheres, offering promising applications in the development of functional foods, especially in cheese production.

Probiotic-Based Mineralized Living Materials to Produce Antimicrobial Yogurts

Mineralization of living cells represents an evolutionary adaptation that enhances cellular resilience to physicochemical stress. Inspired by this strategy, we have here developed hybrid living materials (HLMs), incorporating probiotics into mineralized collagen 3D matrices, with the aim of protecting and promoting the successful oral delivery of the bacteria. Collagen fibrils are simultaneously self-assembled and mineralized in the presence of the probiotics (Lactobacillus acidophilus, La, was used as model), resulting in the integration of the probiotics into the hybrid matrix (i.e., bulk encapsulation). During this process, probiotics are also coated with a nanofilm of apatite mineral (single-cell encapsulation), which provides them with extra protection and reinforces their viability and activity. In fact, the resulting HLM is metabolically active, and maintain the capacity to ferment milk into yogurt with antibacterial activity against the two major foodborne pathogens Pseudomonas aeruginosa (Pa) and Staphylococcus aureus (Sa). Interestingly, the HLM provides probiotics an additional protection in the gastrointestinal environment (i.e., simulated gastric fluid), which is of special interest for healthcare materials for oral administration. The results pave the way for the creation of innovative healthcare materials with enhanced functionalities and the potential to produce probiotic foods with notable antimicrobial properties.

Development of Alginate Composite Microparticles for Encapsulation of Bifidobacterium animalis subsp. lactis

The probiotic bacterium Bifidobacterium animalis subsp. lactis BB-12 (BB-12) was encapsulated in two composites, alginate/agar and alginate/agar/casein. The network structure and physicochemical properties of these composites are influenced by complex interactions, including hydrogen bonding, electrostatic forces between biopolymers, calcium ions, and the encapsulated bacteria. The composites demonstrated a granular surface, with the granules being spatially oriented on the alginate/agar/BB-12 surface and linearly oriented on the alginate/agar/casein/BB-12 surface. They possess a highly organized microparticle structure and exhibit viscoelastic solid-like behavior. The alginate/agar/BB-12 composite showed higher storage modulus, shear stress, and shear strain values, indicating enhanced stability in various physical environments. Both composites displayed good thermal stability, aligning with their rheological properties, confirming their well-ordered structures. Despite differences in composite structures, the release mechanism of bacteria is governed by Fickian diffusion through the composite matrix. Based on physicochemical properties, the alginate/agar/casein composite is recommended for dairy product fermentation, while the alginate/agar composite seems more suitable for oral use. These findings provide new insights into the interactions between bacterial cultures and alginate composite ingredients.

Novel pectin-carboxymethylcellulose-based double-layered mucin/chitosan microcomposites successfully protect the next-generation probiotic Akkermansia muciniphila through simulated gastrointestinal transit and alter microbial communities within colonic ex vivo bioreactors

The rapid acceleration of microbiome research has identified many potential Next Generation Probiotics (NGPs). Conventional formulation processing methods are non-compatible, leading to reduced viability and unconfirmed incorporation into intestinal microbial communities; consequently, demand for more bespoke formulation strategies of such NGPs is apparent. In this study, Akkermansia muciniphila (A.muciniphila) as a candidate NGP was investigated for its growth and metabolism properties, based on which a novel microcomposite-based oral formulation was formed. Initially, a chitosan-based microcomposite was coated with mucin to establish a surface culture of A.muciniphila. This was followed by 'double encapsulation' with pectin (PEC) using a novel Entrapment Deposition by Prilling method to create core-shell double-encapsulated microcapsules. The formulation of A.muciniphila was verified to require no oxygen-restriction properties, and additionally, biopolymers were selected, including carboxymethylcellulose (CMC), that support and enhance its growth; consequently, a high viability (6 log CFU/g) of A.muciniphila microencapsulated in PEC-CMC double-encapsulates was obtained. Subsequently, the high stability of the PEC-CMC double-encapsulates was verified in simulated gastric fluid, successfully protecting and then releasing the A.muciniphila under intestinal conditions. Finally, employing a model of gastrointestinal transit and faecal-inoculated colonic bioreactors, significant alterations in microbial communities following administration and successful establishment of A.muciniphila were demonstrated.

Biopolymer encapsulation for improved probiotic delivery: Advancements and challenges

Probiotics, known for their health benefits as living microorganisms, hold significant importance across various fields, including agriculture, aquaculture, nutraceuticals, and pharmaceuticals. Optimal delivery and storage of probiotic cells are essential to maximize their effectiveness. Biopolymers, derived from living sources, plants, animals, and microbes, offer a natural solution to enhance probiotic capabilities and they possess distinctive qualities such as stability, flexibility, biocompatibility, sustainability, biodegradability, and antibacterial properties, making them ideal for probiotic applications. These characteristics create optimal environments for the swift and precisely targeted delivery of probiotic cells that surpass the effectiveness of unencapsulated probiotic cells. Various encapsulation techniques using diverse biopolymers are employed for this purpose. These techniques are not limited to spray drying, emulsion, extrusion, spray freeze drying, layer by layer, ionic gelation, complex coacervation, vibration technology, electrospinning, phase separation, sol-gel encapsulation, spray cooling, fluidized, air suspension coating, compression coating, co-crystallization coating, cyclodextrin inclusion, rotating disk, and solvent evaporation methods. This review addresses the latest advancements in probiotic encapsulation materials and techniques, bridging gaps in our understanding of biopolymer-based encapsulation systems. Specifically, we address the limitations of current encapsulation methods in maintaining probiotic viability under extreme environmental conditions and the need for more targeted and efficient delivery mechanisms. Focusing on the interactions between biopolymers and probiotics reveals how customized encapsulation approaches can enhance probiotic stability, survival, and functionality. Through detailed comparative analysis of the effectiveness of various encapsulation methods, we identify key strategies for optimizing probiotic deployment in challenging conditions such as high-temperature processing, acidic environments, and gastrointestinal transit. The findings presented in this review highlight the superior performance of novel encapsulation methods using biopolymer blends and advanced technologies like electrospinning and layer-by-layer assembly, which provide enhanced protection and controlled release of probiotics by offering insights into the development of more robust encapsulation systems that ensure the sustained viability and bioavailability of probiotics, thus advancing their application across multiple industries. In conclusion, this paper provides the foundation for future research to refine encapsulation techniques to overcome the challenges of probiotic delivery in clinical and commercial settings.

Dairy-based multi-strain probiotic community successfully mitigated obesity-related gut microbiota dysbiosis in vitro (CoMiniGut)

Introduction. Obesity is a global health concern, affecting individuals of all ages and genders. One promising strategy to combat obesity is by addressing gut microbiota dysbiosis, with probiotics being a reliable intervention. However, single-strain probiotics may not effectively modulate the complex microbial communities in the gut, suggesting the need for multi-strain approaches.Gap Statement. Probiotics are known to benefit gut health; however, the efficacy of single-strain probiotics in modulating gut microbiota is limited. Multi-strain probiotic community (MSPC) may offer a more effective approach for addressing obesity-related gut dysbiosis, but its specific effects on individuals and microbial diversity require further investigation.Aim. This study aimed to evaluate the potential of a dairy-origin MSPC in modulating obesity-related gut microbiota from lean and obese Pakistani volunteers using a simulated CoMiniGut model.Methodology. Gut microbiota from lean and obese volunteers were treated with MSPC in a simulated CoMiniGut system. Bacterial counts, microbial diversity (α- and β-diversity) and microbial community composition were analysed pre- and post-treatment. The impact of MSPC on specific bacterial genera and microbial metabolites was assessed, with statistical significance determined (P≤0.05).Results. The effect of MSPC was individualized, reducing bacterial counts in lean 1 and lean 2 samples, while significantly increasing bacterial counts in obese 2 and obese 3 samples (P≤0.05). MSPC significantly improved α-diversity in lean 2, lean 3, obese 2 and obese 3 samples (P≤0.05). Proteobacteria decreased in the lean group and increased in the obese group post-MSPC treatment. In the lean group, pathogenic bacteria such as Klebsiella, Escherichia and Enterobacter were significantly reduced (P≤0.05), whereas beneficial bacteria like Bifidobacterium and Lactobacillus increased significantly in the obese group (P≤0.05). Among the selected metabolites, only butanoic acid was detected in all tested samples, with MSPC affecting metabolite concentrations and types.Conclusion. MSPC demonstrated a potential for modulating gut microbiota dysbiosis in both lean and obese individuals, with effects on bacterial counts, microbial diversity and metabolite concentrations. MSPC could serve as a promising option for personalized the modulation of gut microbiota in obesity management.

Enhancing Lactobacillus plantarum delivery: Impact of gluconolactone concentration on high-internal-phase emulsion gels and gastrointestinal viability

In this study, the impact of Gluconolactone (GDL) concentration on the formation of high-internal-phase emulsion gels (HIPEGs) and the gastrointestinal digestive viability of Lactobacillus plantarum encapsulated within these HIPEGs were demonstrated. Increasing GDL concentrations led to cross-linking of particles at the oil-water interface, thereby stabilizing smaller oil droplets. The addition of GDL to HIPEs results in a significant increase in the secondary structure of SPI, specifically in β-sheet and β-turn formations, accompanied by a reduction in α-helix percentage. This alteration enhanced the binding effect of protein on water, leading to changes in intermolecular force. Notably, HIPEGs containing 3.0% GDL demonstrated superior encapsulation efficiency and delivery efficiency, reaching 99.0% and 84.5%, respectively. After 14 d of continuous zebrafishs feeding, the intestinal viable cells count of Lactobacillus plantarum reached 1.18 × 107 CFU/mL. This finding supports the potential use of HIPEGs as a probiotic delivery carrier, effectively enhancing the intestinal colonization rate.

Effect of Encapsulation of Lactobacillus casei in Alginate-Tapioca Flour Microspheres Coated with Different Biopolymers on the Viability of Probiotic Bacteria

To realize the health benefits of probiotic bacteria, they must withstand processing and storage conditions and remain viable after use. The encapsulation of these probiotics in the form of microspheres containing tapioca flour as a prebiotic and vehicle component in their structure or shell affords symbiotic effects that improve the survival of probiotics under unfavorable conditions. Microencapsulation is one such method that has proven to be effective in protecting probiotics from adverse conditions while maintaining their viability and functionality. The aim of the work was to obtain high-quality microspheres that can act as carriers of Lactobacillus casei bacteria and to assess the impact of encapsulation on the viability of probiotic microorganisms in alginate microspheres enriched with a prebiotic (tapioca flour) and additionally coated with hyaluronic acid, chitosan, or gelatin. The influence of the composition of microparticles on the physicochemical properties and the viability of probiotic bacteria during storage was examined. The optimal composition of microspheres was selected using the design of experiments using statistical methods. Subsequently, the size, morphology, and cross-section of the obtained microspheres, as well as the effectiveness of the microsphere coating with biopolymers, were analyzed. The chemical structure of the microspheres was identified by using Fourier-transform infrared spectrophotometry. Raman spectroscopy was used to confirm the success of coating the microspheres with the selected biopolymers. The obtained results showed that the addition of tapioca flour had a positive effect on the surface modification of the microspheres, causing the porous structure of the alginate microparticles to become smaller and more sealed. Moreover, the addition of prebiotic and biopolymer coatings of the microspheres, particularly using hyaluronic acid and chitosan, significantly improved the survival and viability of the probiotic strain during long-term storage. The highest survival rate of the probiotic strain was recorded for alginate-tapioca flour microspheres coated with hyaluronic acid, at 5.48 log CFU g-1. The survival rate of L. casei in that vehicle system was 89% after storage for 30 days of storage.

Single-cell encapsulation systems for probiotic delivery: Armor probiotics

Functional foods or drugs based on probiotics have gained unprecedented attention and development due to the increasingly clear relationship between probiotics and human health. Probiotics can regulate intestinal microbiota, dynamically participating in various physiological activities to directly affect human health. Some probiotic-based functional preparations have shown great potential in treating multiple refractory diseases. Currently, the survival and activity of probiotic cells in complex environments in vitro and in vivo have taken priority, and various encapsulation systems based on food-derived materials have been designed and constructed to protect and deliver probiotics. However, traditional encapsulation technology cannot achieve precise protection for a single probiotic, which makes it unable to have a significant effect after release. In this case, single-cell encapsulation systems can be assembled based on biological interfaces to protect and functionalize individual probiotic cells, maximizing their physiological activity. This review discussed the arduous challenges of probiotics in food processing, storage, human digestion, and the commonly used probiotic encapsulation system. Besides, a novel technology of probiotic encapsulation was introduced based on single-cell coating, namely, "armor probiotics". We focused on the classification, structural design, and functional characteristics of armor coatings, and emphasized the essential functional characteristics of armor probiotics in human health regulation, including regulating intestinal health and targeted bioimaging and treatment of diseased tissues. Subsequently, the benefits, limitations, potential challenges, as well as future direction of armor probiotics were put forward. We hope this review may provide new insights and ideas for developing a single-cell probiotics encapsulating system.

Controlled release of microorganisms from engineered living materials

Probiotics offer therapeutic benefits by modulating the local microbiome, the host immune response, and the proliferation of pathogens. Probiotics have the potential to treat complex diseases, but their persistence or colonization is required at the target site for effective treatment. Although probiotic persistence can be achieved by repeated delivery, no biomaterial that releases clinically relevant doses of metabolically active probiotics in a sustained manner has been previously described. Here, we encapsulate stiff probiotic microorganisms within relatively less stiff hydrogels and show a generic mechanism where these microorganisms proliferate and induce hydrogel fracture, resulting in microbial release. Importantly, this fracture-based mechanism leads to microorganism release with zero-order release kinetics. Using this mechanism, small (∼1 μL) engineered living materials (ELMs) release >10 8 colony-forming-units (CFUs) of E. coli in 2 h. This release is sustained for at least 10 days. Cell release can be varied by more than three orders of magnitude by varying initial cell loading and modulating the mechanical properties of encapsulating matrix. As the governing mechanism of microbial release is entirely mechanical, we demonstrate controlled release of model Gram-negative, Gram-positive, and fungal probiotics from multiple hydrogel matrices.

SIGNIFICANCE

Probiotics offer therapeutic benefits and have the potential to treat complex diseases, but their persistence at the target site is often required for effective treatment. Although probiotic persistence can be achieved by repeated delivery, no biomaterial that releases metabolically active probiotics in a sustained manner has been developed yet. This work demonstrates a generic mechanism where stiff probiotics encapsulated within relatively less stiff hydrogels proliferate and induce hydrogel fracture. This allows a zero-order release of probiotics which can be easily controlled by adjusting the properties of the encapsulating matrices. This generic mechanism is applicable for a wide range of probiotics with different synthetic matrices and has the potential to be used in the treatment of a broad range of diseases.

Encapsulation of Lacticaseibacillus casei and Lactobacillus acidophilus using Elaeagnus angustifolia L. flour as encapsulating material by emulsion method

In this study, Lacticaseibacillus casei and Lactobacillus acidophilus probiotic bacteria were encapsulated using oleaster flour, which is rich in phenolic compounds and has prebiotic properties as potential. The optimum conditions required for the encapsulation of L. casei and L. acidophilus bacteria with maximum efficiency using oleaster flour were determined by central composite design-response surface methodology. As a result of the optimization process, the encapsulation efficiency for L. casei and L. acidophilus capsules was 93.66 ± 2.58% and 74.97 ± 1.34%, respectively. The capsule sizes of L. casei and L. acidophilus encapsulated with oleaster flour were determined by scanning electron microscopy to be 104.8 ± 26.3 and 95.7 ± 12.1 μm, respectively. Fourier transform infrared spectroscopy analyses showed that there was no change in the structure of the encapsulation material, oleaster flour, after encapsulation. Also, the storage stability of free and encapsulated bacteria was investigated, and it was found that the viability losses of encapsulated probiotic bacteria were less than those of free probiotic bacteria. Finally, the effect of encapsulation on bacterial viability during in vitro gastrointestinal digestion was investigated, which is the main purpose of the study. While free probiotic bacteria cannot reach the intestinal environment alive after in vitro gastrointestinal digestion due to pH and enzyme effects, encapsulated L. casei and L. acidophilus bacteria largely preserved their viability, and their postdigestion viability was 39.59 ± 1.50% and 36.28 ± 0.01%, respectively. The results showed successful encapsulation of L. casei and L. acidophilus probiotic bacteria with oleaster flour.

Functional modification of gut bacteria for disease diagnosis and treatment

Intestinal bacteria help keep humans healthy by regulating lipid and glucose metabolism as well as the immunological and neurological systems. Oral treatment using intestinal bacteria is limited by the high acidity of stomach fluids and the immune system's attack on foreign bacteria. Scientists have created coatings and workarounds to overcome these limitations and improve bacterial therapy. These preparations have demonstrated promising outcomes, with advances in synthetic biology and optogenetics improving their focused colonization and controlled release. Engineering bacteria preparations have become a revolutionary therapeutic approach that converts intestinal bacteria into cellular factories for medicinal chemical synthesis. The present paper discusses various aspects of engineering bacteria preparations, including wrapping materials, biomedical uses, and future developments.

Characterization of lactic acid bacteria isolated from human breast milk and their bioactive metabolites with potential application as a probiotic food supplement

The probiotic properties of twenty-five lactic acid bacteria (LAB) isolated from human breast milk were investigated considering their resistance to gastrointestinal conditions and proteolytic activity. Seven LAB were identified and assessed for auto- and co-aggregation capacity, antibiotic resistance, and behavior during in vitro gastrointestinal digestion. Three Lacticaseibacillus strains were further evaluated for antifungal activity, metabolite production (HPLC-Q-TOF-MS/MS and GC-MS/MS) and proteolytic profiles (SDS-PAGE and HPLC-DAD) in fermented milk, whey, and soy beverage. All strains resisted in vitro gastrointestinal digestion with viable counts higher than 7.9 log10 CFU mL-1 after the colonic phase. Remarkable proteolytic activity was observed for 18/25 strains. Bacterial auto- and co-aggregation of 7 selected strains reached values up to 23 and 20%, respectively. L. rhamnosus B5H2, L. rhamnosus B9H2 and L. paracasei B10L2 inhibited P. verrucosum, F. verticillioides and F. graminearum fungal growth, highlighting L. rhamnosus B5H2. Several metabolites were identified, including antifungal compounds such as phenylacetic acid and 3-phenyllactic acid, and volatile organic compounds produced in fermented milk, whey, and soy beverage. SDS-PAGE demonstrated bacterial hydrolysis of the main milk (caseins) and soy (glycines and beta-conglycines) proteins, with no apparent hydrolysis of whey proteins. However, HPLC-DAD revealed alpha-lactoglobulin reduction up to 82% and 54% in milk and whey, respectively, with L. rhamnosus B5H2 showing the highest proteolytic activity. Overall, the three selected Lacticaseibacillus strains demonstrated probiotic capacity highlighting L. rhamnosus B5H2 with remarkable potential for generating bioactive metabolites and peptides which are capable of promoting human health.

Novel strategies for modulating the gut microbiome for cancer therapy

Recent advancements in genomics, transcriptomics, and metabolomics have significantly advanced our understanding of the human gut microbiome and its impact on the efficacy and toxicity of anti-cancer therapeutics, including chemotherapy, immunotherapy, and radiotherapy. In particular, prebiotics, probiotics, and postbiotics are recognized for their unique properties in modulating the gut microbiota, maintaining the intestinal barrier, and regulating immune cells, thus emerging as new cancer treatment modalities. However, clinical translation of microbiome-based therapy is still in its early stages, facing challenges to overcome physicochemical and biological barriers of the gastrointestinal tract, enhance target-specific delivery, and improve drug bioavailability. This review aims to highlight the impact of prebiotics, probiotics, and postbiotics on the gut microbiome and their efficacy as cancer treatment modalities. Additionally, we summarize recent innovative engineering strategies designed to overcome challenges associated with oral administration of anti-cancer treatments. Moreover, we will explore the potential benefits of engineered gut microbiome-modulating approaches in ameliorating the side effects of immunotherapy and chemotherapy.

Encapsulation of Lactobacillus plantarum in W1/O/W2 double emulsions stabilized with the high-intensity ultrasound-treated pea protein and pectin

This study focuses on developing a water-in-oil-in-water (W1/O/W2) double emulsion system using high-intensity ultrasound (HIU)-treated pea protein isolate (HIU-PPI) and pectin to encapsulate Lactobacillus plantarum (L. plantarum). The effects of ultrasound treatment on pea protein isolate (PPI) characteristics such as solubility, particle size, emulsification, surface hydrophobicity, and surface free sulfhydryl group were examined, determining optimal HIU processing conditions was 400 W for 10 min. The developed W1/O/W2 double emulsion system based on HIU-PPI demonstrated effective encapsulation and protection of L. plantarum, especially at the HIU-PPI concentration of 4 %, achieving an encapsulation efficiency of 52.65 %. Incorporating both HIU-PPI and pectin as emulsifiers increased the particle size and significantly enhanced the emulsion's viscosity. The highest bacterial encapsulation efficiency of the emulsion, 59.94 %, was attained at a HIU to pectin concentration ratio of 3:1. These emulsions effectively encapsulate and protect L. plantarum, with the concentration of HIU-PPI being a critical factor in enhancing probiotic survival under simulated gastrointestinal digestion. However, the concurrent utilization of pectin and HIU-PPI as emulsifiers did not provide a notable advantage compared to the exclusive use of HIU-PPI in enhancing probiotic viability during in vitro simulated digestion. This research offers valuable perspectives for the food industry on harnessing environmentally friendly, plant-based proteins as emulsifiers in probiotic delivery systems. It underscores the potential of HIU-modified pea protein and pectin in developing functional food products that promote the health benefits of probiotics.

Multistimuli responsive microcapsules produced by the prilling/vibration technique for targeted colonic delivery of probiotics

This study aimed to microencapsulate the probiotic strain Lactiplantibacillus plantarum 4S6R (basonym Lactobacillus plantarum) in both microcapsules and microspheres by prilling/vibration technique. A specific polymeric mixture, selected for its responsiveness to parallel colonic stimuli, was individuated as a carrier of microparticles. Although the microspheres were consistent with some critical quality parameters, they showed a low encapsulation efficiency and were discarded. The microcapsules produced demonstrated high yields (97.52%) and encapsulation efficiencies (90.06%), with dimensional analysis and SEM studies confirming the desired size morphology and structure. The results of thermal stress tests indicate the ability of the microcapsules to protect the probiotic. Stability studies showed a significant advantage of the microcapsules over non-encapsulated probiotics, with greater stability over time. The release study under simulated gastrointestinal conditions demonstrated the ability of the microcapsules to protect the probiotics from gastric acid and bile salts, ensuring their viability. Examination in a simulated faecal medium revealed the ability of the microcapsules to release the bacteria into the colon, enhancing their beneficial impact on gut health. This research suggests that the selected mixture of reactive polymers holds promise for improving the survival and efficacy of probiotics in the gastrointestinal tract, paving the way for the development of advanced probiotic products.

Encapsulation of Active Substances in Natural Polymer Coatings

Already used in the food, pharmaceutical, cosmetic, and agrochemical industries, encapsulation is a strategy used to protect active ingredients from external degradation factors and to control their release kinetics. Various encapsulation techniques have been studied, both to optimise the level of protection with respect to the nature of the aggressor and to favour a release mechanism between diffusion of the active compounds and degradation of the barrier material. Biopolymers are of particular interest as wall materials because of their biocompatibility, biodegradability, and non-toxicity. By forming a stable hydrogel around the drug, they provide a 'smart' barrier whose behaviour can change in response to environmental conditions. After a comprehensive description of the concept of encapsulation and the main technologies used to achieve encapsulation, including micro- and nano-gels, the mechanisms of controlled release of active compounds are presented. A panorama of natural polymers as wall materials is then presented, highlighting the main results associated with each polymer and attempting to identify the most cost-effective and suitable methods in terms of the encapsulated drug.

Frontier in gellan gum-based microcapsules obtained by emulsification: Core-shell structure, interaction mechanism, intervention strategies

As a translucent functional gel with biodegradability, non-toxicity and acid resistance, gellan gum has been widely used in probiotic packaging, drug delivery, wound dressing, metal ion adsorption and other fields in recent years. Because of its remarkable gelation characteristics, gellan gum is suitable as the shell material of microcapsules to encapsulate functional substances, by which the functional components can improve stability and achieve delayed release. In recent years, many academically or commercially reliable products have rapidly emerged, but there is still a lack of relevant reports on in-depth research and systematic summaries regarding the process of microcapsule formation and its corresponding mechanisms. To address this challenge, this review focuses on the formation process and applications of gellan gum-based microcapsules, and details the commonly used preparation methods in microcapsule production. Additionally, it explores the impact of factors such as ion types, ion strength, temperature, pH, and others present in the solution on the performance of the microcapsules. On this basis, it summarizes and analyzes the prospects of gellan gum-based microcapsule products. The comprehensive insights from this review are expected to provide inspiration and design ideas for researchers.

Effectiveness of Psychobiotics in the Treatment of Psychiatric and Cognitive Disorders: A Systematic Review of Randomized Clinical Trials

In this study, a systematic review of randomized clinical trials conducted from January 2000 to December 2023 was performed to examine the efficacy of psychobiotics-probiotics beneficial to mental health via the gut-brain axis-in adults with psychiatric and cognitive disorders. Out of the 51 studies involving 3353 patients where half received psychobiotics, there was a notably high measurement of effectiveness specifically in the treatment of depression symptoms. Most participants were older and female, with treatments commonly utilizing strains of Lactobacillus and Bifidobacteria over periods ranging from 4 to 24 weeks. Although there was a general agreement on the effectiveness of psychobiotics, the variability in treatment approaches and clinical presentations limits the comparability and generalization of the findings. This underscores the need for more personalized treatment optimization and a deeper investigation into the mechanisms through which psychobiotics act. The research corroborates the therapeutic potential of psychobiotics and represents progress in the management of psychiatric and cognitive disorders.

Alginate- and Chitosan-Modified Gelatin Hydrogel Microbeads for Delivery of E. coli Phages

Bacterial infections are among the most significant health problems/concerns worldwide. A very critical concern is the rapidly increasing number of antibiotic-resistant bacteria, which requires much more effective countermeasures. As nature's antibacterial entities, bacteriophages shortly ("phages") are very important alternatives to antibiotics, having many superior features compared with antibiotics. The development of phage-carrying controlled-release formulations is still challenging due to the need to protect their activities in preparation, storage, and use, as well as the need to create more user-friendly forms by considering their application area/site/conditions. Here, we prepared gelatin hydrogel microbeads by a two-step process. Sodium alginate was included for modification within the initial recipes, and these composite microbeads were further coated with chitosan. Their swelling ratio, average diameters, and Zeta potentials were determined, and degradations in HCl were demonstrated. The target bacteria Escherichia coli (E.coli) and its specific phage (T4) were obtained from bacterial culture collections and propagated. Phages were loaded within the microbeads with a simple method. The phage release characteristics were investigated comparatively and were demonstrated here. High release rates were observed from the gelatin microbeads. It was possible to reduce the phage release rate using sodium alginate in the recipe and chitosan coating. Using these gelatin-based microbeads as phage carrier matrices-especially in lyophilized forms-significantly improved the phage stability even at room temperature. It was concluded that phage release from gelatin hydrogel microbeads could be further controlled by alginate and chitosan modifications and that user-friendly lyophilized phage formulations with a much longer shelf life could be produced.

The emerging tumor microbe microenvironment: From delineation to multidisciplinary approach-based interventions

Intratumoral microbiota has become research hotspots, and emerges as a non-negligent new component of tumor microenvironments (TME), due to its powerful influence on tumor initiation, metastasis, immunosurveillance and prognosis despite in low-biomass. The accumulations of microbes, and their related components and metabolites within tumor tissues, endow TME with additional pluralistic features which are distinct from the conventional one. Therefore, it's definitely necessary to comprehensively delineate the sophisticated landscapes of tumor microbe microenvironment, as well as their functions and related underlying mechanisms. Herein, in this review, we focused on the fields of tumor microbe microenvironment, including the heterogeneity of intratumor microbiota in different types of tumors, the controversial roles of intratumoral microbiota, the basic features of tumor microbe microenvironment (i.e., pathogen-associated molecular patterns (PAMPs), typical microbial metabolites, autophagy, inflammation, multi-faceted immunomodulation and chemoresistance), as well as the multidisciplinary approach-based intervention of tumor microbiome for cancer therapy by applying wild-type or engineered live microbes, microbiota metabolites, antibiotics, synthetic biology and rationally designed biomaterials. We hope our work will provide valuable insight to deeply understand the interplay of cancer-immune-microbial, and facilitate the development of microbes-based tumor-specific treatments.

Symbiotic microparticles produced through spray-drying-induced in situ alginate crosslinking for the preservation of Pediococcus pentosaceus viability

Probiotic microorganisms are a promising alternative to antibiotics in preventing and treating bacterial infections. Within the probiotic group, the lactic acid bacteria (LAB)stand out for their health benefits and for being recognized as safe by regulatory agencies. However, these microorganisms are sensitive to various environmental conditions, including the acidic environment of the stomach. Faced with these obstacles, this work aimed to promote the symbiotic microencapsulation of LAB in a composite matrix of alginate and prebiotics to enhance their survival and improve their probiotic activity during gastrointestinal transit. We evaluated the effect of inulin, fructo-oligosaccharides (FOS) and mannan-oligosaccharides (MOS) as prebiotic sources on the growth of Pediococcus pentosaceus LBM34 strain, finding that MOS favored LAB growth and maintenance of microencapsulated cell viability. The symbiotic microparticles were produced using the spray-drying technique with an average size of 10 μm, a smooth surface, and a composition that favored the stabilization of live cells according to the FTIR and the thermal analysis of the material. The best formulation was composed of 1 % of alginate, 10 % MOS and 1 % M10 (% w/v), which presented notable increases in the survival rates of the probiotic strain in both alkaline and acidic conditions. Therefore, this industrially scalable approach to symbiotic LAB microencapsulation can facilitate their growth and colonization within the host. This effort aims to contribute to reducing antibiotic reliance and mitigating the emergence of new zoonotic diseases, which pose significant challenges to public health.

LETHAL TOXIN NEUTRALIZING ANTIBODY RESPONSE INDUCED FOLLOWING ORAL VACCINATION WITH A MICROENCAPSULATED BACILLUS ANTHRACIS STERNE STRAIN 34F2 VACCINE PROOF-OF-CONCEPT STUDY IN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS)

Improved methods are needed to prevent wildlife deaths from anthrax. Caused by Bacillus anthracis, naturally occurring outbreaks of anthrax are frequent but unpredictable. The commercially available veterinary vaccine is labeled for subcutaneous injection and is impractical for large-scale wildlife vaccination programs; therefore, oral vaccination is the most realistic method to control and prevent these outbreaks. We reported the induction of an anthrax-specific lethal toxin (LeTx) neutralizing antibody response in mice following oral vaccination with alginate microcapsules containing B. anthracis Sterne strain 34F2 spores, coated with poly-L-lysine (PLL) and vitelline protein B (VpB). We continued evaluating our novel vaccine formulation through this proof-of-concept study in white-tailed deer (WTD; Odocoileus virginianus; n = 9). We orally vaccinated WTD via needle-free syringe with three formulations of the encapsulated vaccine: 1) PLL-VpB-coated microcapsules with 107-8 spores/ml (n = 5), 2) PLL-VpB-coated microcapsules with 109-10 spores/ml (n = 2), and 3) PLL-coated microcapsules with 109-10 spores/ml (n = 2). Although the limited sample sizes require continued experimentation, we observed an anthrax-specific antibody response in WTD serum following oral vaccination with PLL-coated microcapsules containing 109 spores/ ml. Furthermore, this antibody response neutralized anthrax LeTx in vitro, suggesting that continued development of this vaccine may allow for realistic wildlife anthrax vaccination programs.

Nanozyme-Enhanced Probiotic Spores Regulate the Intestinal Microenvironment for Targeted Acute Gastroenteritis Therapy

Antibiotic therapeutics to combat intestinal pathogen infections often exacerbate microbiota dysbiosis and impair mucosal barrier functions. Probiotics are promising strategies, because they inhibit pathogen colonization and improve intestinal microbiota imbalance. Nevertheless, their limited targeting ability and susceptibility to oxidative stress have hindered their therapeutic potential. To tackle these challenges, Ces3 is synthesized by in situ growth of CeO2 nanozymes with positive charges on probiotic spores, facilitating electrostatic interactions with negatively charged pathogens and possessing a high reactive oxygen species (ROS) scavenging activity. Importantly, Ces3 can resist the harsh environment of the gastrointestinal tract. In mice with S. Typhimurium-infected acute gastroenteritis, Ces3 shows potent anti-S. Typhimurium activity, thereby alleviating the dissemination of S. Typhimurium into other organs. Additionally, owing to its O2 deprivation capacity, Ces3 promotes the proliferation of anaerobic probiotics, reshaping a healthy intestinal microbiota. This work demonstrates the promise of combining antibacterial, anti-inflammatory, and O2 content regulation properties for acute gastroenteritis therapy.

Encapsulation of conjugated linoleic acid and ruminant trans fatty acids to study the prevention of metabolic syndrome-a review

Studies have reported the potential benefits of consuming conjugated linoleic acid (CLA) and ruminant trans fatty acids (R-TFAs) in reducing the risk factors of metabolic syndrome (MetS). In addition, encapsulation of CLA and R-TFAs may improve their oral delivery and further decrease the risk factors of MetS. The objectives of this review were (1) to discuss the advantages of encapsulation; (2) to compare the materials and techniques used for encapsulating CLA and R-TFAs; and (3) to review the effects of encapsulated vs non-encapsulated CLA and R-TFAs on MetS risk factors. Examination of papers citing micro- and nano-encapsulation methods used in food sciences, as well as the effects of encapsulated vs non-encapsulated CLA and R-TFAs, was conducted using the PubMed database. A total of 84 papers were examined; of these, 18 studies were selected that contained information on the effects of encapsulated CLA and R-TFAs. The 18 studies that described encapsulation of CLA or R-TFAs indicated that micro- or nano-encapsulation processes stabilized CLA and prevented oxidation. CLA was mainly encapsulated using carbohydrates or proteins. So far, oil-in-water emulsification followed by spray-drying were the frequently used techniques for encapsulation of CLA. Further, 4 studies investigated the effects of encapsulated CLA on MetS risk factors compared with non-encapsulated CLA. A limited number of studies investigated the encapsulation of R-TFAs. The effects of encapsulated CLA or R-TFAs on the risk factors for MetS remain understudied; thus, additional studies comparing the effects of encapsulated and non-encapsulated CLA or R-TFAs are needed.

Challenges and Therapeutic Approaches for the Protein Delivery System: A Review

The protein delivery system is one of the innovative or novel drug delivery systems in the present era. Proteins play an indispensable role in our body and are mainly found in every part, like tissue and cells of our body. It also controls various functions, such as maintaining our tissue, transportation, muscle recovery, enzyme production and acting as an energy source for our body. Protein therapeutics have big future perspectives, and their use in the treatment of a wide range of serious diseases has transformed the delivery system in the pharmaceutical and biotechnology industries. The chief advantage of protein delivery is that it can be delivered directly to the systemic circulation. So far, parenteral routes, such as intravenous, intramuscular, and subcutaneous, are the most often used method of administering protein drugs. Alternative routes like buccal, oral, pulmonary, transdermal, nasal, and ocular routes have also shown a remarkable success rate. However, as with all other types of delivery, here, several challenges are posed due to the presence of various barriers, such as the enzymatic barrier, intestinal epithelial barrier, capillary endothelial barrier, and blood-brain barrier. There are several approaches that have been explored to overcome these barriers, such as chemical modification, enzymatic inhibitors, penetration enhancers, and mucoadhesive polymers. This review article discusses the protein, its functions, routes of administration, challenges, and strategies to achieve ultimate formulation goals. Recent advancements like the protein Pegylation method and Depofoam technology are another highlight of the article.

Characteristics of Lactobacillus casei probiotic microparticles in L-type methacrylic acid copolymer matrix

Lactobacillus casei (LC) is a type of lactic acid bacterium that is known for its beneficial probiotic properties. However, it is not typically found in the human intestine because it lacks acid resistance. LC thrives in an optimal pH environment of 6.8 and can be initiated in a more acidic environment at a pH of 3.5. This study purposed to compare the effect of L-type methacrylic acid copolymer (MAC) as a matrix (0.50%, 0.75%, and 1.00%) on the physical characteristics of LC probiotic microparticles made by the spray drying process. Probiotic microparticles were also made from a dry suspension of LC FNCC 0090 bacteria and dispersed in a solution of L-type MAC. The results showed that a rise in matrix content by 1.00% increased particle size (4.47 ± 0.19 µm) and reduced moisture content (7.45 ± 0.11%). The analysis of microparticle morphology also indicated a positive correlation between the level of L-type MAC and the production of smooth, nonporous, and almost spherical shapes. In addition, it was observed that encapsulation efficiency (92.46 ± 0.17%) and protection against stomach acid (98.17% ±1.17%) increased with the level of the matrix.

pH-dependent pressure-sensitive colonic capsules for the delivery of aqueous bacterial suspensions

Microbiome-based therapies hold great promise for treating various diseases, but the efficient delivery of live bacteria to the colon remains a challenge. Furthermore, current oral formulations, such as lyophilized bacterial capsules or tablets, are produced using processes that can decrease bacterial viability. Consequently, high dosages are required to achieve efficacy. Herein, we report the design of pressure-sensitive colonic capsules for the encapsulation and delivery of aqueous suspensions of live bacteria. The capsules consisted of 2 functional thin-films (hydrophobic and enteric) of ethyl cellulose and Eudragit S100 dip-coated onto hydroxypropyl methylcellulose molds. The capsules could be loaded with aqueous media and provide protection against acidic fluids and, to some extent, oxygen diffusion, suggesting their potential suitability for delivering anaerobic bacterial strains. Disintegration and mechanical studies indicated that the capsules could withstand transit through the stomach and upper/proximal small intestinal segments and rupture in the ileum/colon. In vitro studies showed that bacterial cells (anaerobic and aerobic commensals) remained highly viable (74-98%) after encapsulation and exposure to the simulated GI tract conditions. In vivo studies with a beagle dog model revealed that 67% of the capsules opened after 3.5 h, indicating content release in the distal gastrointestinal tract. These data demonstrate that live aqueous bacterial suspensions comprised of both aerobic and anaerobic commensals can be encapsulated and in the future might be efficiently delivered to the distal gastrointestinal tract, suggesting the practical applications of these capsules in microbiome-based therapies.

Leuconostoc mesenteroides subsp. strain NTM048 ameliorated nasal symptoms in patients with Japan cedar pollinosis: Randomized, double-blind, and placebo-controlled trial

BACKGROUND

Lactobacillales including L mesenteroides have beneficial effects on human health, including improvement of psychological status and alleviation of allergic rhinitis. In mice, L mesenteroides subsp. strain NTM048 (NTM048) increased intestinal s-IgA. In humans, however, the effects of NTM048 on s-IgA secretion have been unclear.

STUDY

This 16-week trial was performed using a double-blind, placebo-controlled, parallel group design. We aimed to establish whether Leuconostoc mesenteroides subsp. strain NTM048 increases the secretion of s-IgA in saliva. Forty healthy adults and forty patients with Japanese cedar pollinosis were recruited. Participants took either 2 test capsules including NTM048 (1010 CFU/day), or 2 placebo capsules per day, for 16 weeks. They were asked to collect their saliva and answered POMS2, a questionnaire about psychological status. The patients also answered questions about nasal symptoms. Blood samples were collected from the patients with Japanese Cedar pollinosis. Stool samples were collected at the start and on the last day of the trial.

RESULTS

All subjects completed the trial. It was conducted during the season when Japanese cedar pollen is most scattered. Serum concentration of Japanese cedar pollen-specific IgE was > 2.0 UA/mL in patients with Japanese cedar pollinosis. The amount of s-IgA in saliva was not increased by NTM048 in overall subjects, and Japanese cedar pollen-specific IgE was not changed by NTM048 in patients with Japanese cedar pollinosis. The symptom of nasal blockage was improved by NTM048 12 weeks after the start of trial. post hoc analysis indicated a positive correlation between improving psychological status and the increase in occupation ratio of lactobacillus including NTM048.

CONCLUSION

The amount of s-IgA in saliva was not increased by NTM048, but nasal blockage was improved by it. Psychological status might be improved if dosage of NTM048 is raised to the degree that NTM048 might be increased in the intestinal tract.

Limosilactobacillus reuteri DSM 17938 reverses gut metabolic dysfunction induced by Western diet in adult rats

Introduction

Microencapsulation of probiotic bacteria is an efficient and innovative new technique aimed at preserving bacterial survival in the hostile conditions of the gastrointestinal tract. However, understanding whether a microcapsule preserves the effectiveness of the bacterium contained within it is of fundamental importance.

Methods

Male Wistar rats aged 90 days were fed a control diet or a Western diet for 8 weeks, with rats fed the Western diet divided into three groups: one receiving the diet only (W), the second group receiving the Western diet and free L. reuteri DSM 17938 (WR), and the third group receiving the Western diet and microencapsulated L. reuteri DSM 17938 (WRM). After 8 weeks of treatment, gut microbiota composition was evaluated, together with occludin, one of the tight junction proteins, in the ileum and the colon. Markers of inflammation were also quantified in the portal plasma, ileum, and colon, as well as markers for gut redox homeostasis.

Results

The Western diet negatively influenced the intestinal microbiota, with no significant effect caused by supplementation with free and microencapsulated L. reuteri. However, L. reuteri, in both forms, effectively preserved the integrity of the intestinal barrier, thus protecting enterocytes from the development of inflammation and oxidative stress.

Conclusion

From these whole data, it emerges that L. reuteri DSM 17938 can be an effective probiotic in preventing the unhealthy consequences of the Western diet, especially in the gut, and that microencapsulation preserves the probiotic effects, thus opening the formulation of new preparations to be able to improve gut function independent of dietary habits.

Protective Effect of Alginate Microcapsules with Different Rheological Behavior on Lactiplantibacillus plantarum 299v

Alginate encapsulation is a well-known technique used to protect microorganisms from adverse conditions. However, it is also known that the viscosity of the alginate is dependent on its composition and degree of polymerization and that thermal treatments, such as pasteurization and sterilization, can affect the structure of the polymer and decrease its protection efficiency. The goal of this study was to evaluate the protective effect of encapsulation, using alginates of different viscosities treated at different temperatures, on Lactiplantibacillus plantarum 299v under in vitro gastrointestinal conditions and cold storage at 4 °C and -15 °C, respectively. Steady- and dynamic-shear rheological tests were used to characterize the polymers. Thermal treatments profoundly affected the rheological characteristics of alginates with high and low viscosity. However, the solutions and gels of the low-viscosity alginate were more affected at a temperature of 117 °C. The capsules elaborated with high-viscosity alginate solution and pasteurized at 63 °C for 30 min provided better protection to the cells of L. plantarum 299v under simulated gastrointestinal and cold storage conditions.

Gastrointestinal Microenvironment Responsive Nanoencapsulation of Probiotics and Drugs for Synergistic Therapy of Intestinal Diseases

The gut microbiota are prominent in preserving intestinal environmental homeostasis and managing human health, and their dysbiosis has been directly related to many kinds of intestinal diseases. Probiotics-based therapy appears as a promising approach for the treatment of gut microbiota dysbiosis, while it always suffers from limited bioavailability and therapeutic effect after oral administration. Herein, we presented a facile and safe strategy to treat colitis by nanoencapsulation of probiotics and an anti-inflammatory agent, 5-aminosalicylic acid (5-ASA), within the gastrointestinal microenvironment responsive alginate polysaccharide. Because of acid resistance, the alginate-based coating protected probiotics from the harsh gastric condition. The coating could be disintegrated to release probiotics and 5-ASA upon arriving in the intestinal tract, where the pH is normally higher than 5. In the dextran sulfate sodium-induced colitis mouse model, probiotics recovered their bioactivities and acted together with anti-inflammatory 5-ASA to alleviate colitis by upregulating microbiota richness and diversity, reducing expression of proinflammatory cytokines, and restoring intestinal barriers. This work demonstrated the synergistic therapy of intestinal diseases based on alginate-encapsulated probiotics and a clinical drug, which provided an extensive method to improve the therapeutic effect of oral microecologics.

Co-encapsulation of probiotics with acylglycerols in gelatin-gum arabic complex coacervates: Stability evaluation under adverse conditions

Co-encapsulation of acylglycerols and probiotics may improve the resistance of probiotics to adverse conditions. In this study, three probiotic microcapsule models were constructed using gelatin (GE)-gum arabic (GA) complex coacervate as wall material: microcapsules containing only probiotics (GE-GA), microcapsules containing triacylglycerol (TAG) oil and probiotics (GE-T-GA) and microcapsules containing diacylglycerol (DAG) oil and probiotics (GE-D-GA). The protective effects of three microcapsules on probiotic cells under environmental stresses (freeze-drying, heat treatment, simulated digestive fluid and storage) were evaluated. The results of cell membrane fatty acid composition and Fourier transform infrared (FTIR) spectroscopy revealed that GE-D-GA could improve the fluidity of cell membrane, maintain the stability of protein and nucleic acid structure, and decrease the damage of cell membrane. These characteristics supported the high freeze-dried survival rate (96.24 %) of GE-D-GA. Furthermore, regardless of thermotolerance or storage, GE-D-GA showed the best cell viability retention. More importantly, GE-D-GA provided the best protection for probiotics under simulated gastrointestinal conditions, as the presence of DAG reduced cell damage during freeze-drying and the degree of contact between probiotics and digestive fluids. Therefore, co-microencapsulation of DAG oil and probiotics is a promising strategy to resist adverse conditions.

Fortification of orange juice with microencapsulated Kocuria flava Y4 towards a novel functional beverage: Biological and quality aspects

To commercialize functional foods, probiotics must exhibit high resistance and acceptable stability under various unfavorable conditions to maintain the quality of fruit juices. This study will provide an insight into fortification of orange juice with a plant probiotic Kocuria flava Y4 by microencapsulation. Therefore, this study investigated the colony release, physicochemical and phytochemical parameters, and antioxidant activity of the orange juice exposed to microencapsulated probiotics and the one without probiotics (control). Evaluation of orange juice on the growth of probiotic bacteria showed that the fortification with alginate and psyllium micro-particles showed highest encapsulation efficiency (99.01%) and acceptable viability of probiotic cells (8.12 ± 0.077 CFU/mL) during five weeks storage at 4 °C. The morphology and functional properties of beads was studied by SEM, Zeta-potential and FTIR analysis. The sucrose and organic acids concentrations decreased significantly during fortification period (0-72 h) except ascorbic acid. Furthermore, glucose, pH, acidity, TSS were maintained. The results affirm the suitability and feasibility of developing a plant probiotic beverage using orange juice by encapsulation method.

Reductase-Labile Peptidic Supramolecular Hydrogels Aided in Oral Delivery of Probiotics

Oral delivery of probiotics has been a promising method for treatment of inflammatory bowel diseases (IBDs). However, probiotics always suffer from substantial loss of viability due to the harsh gastrointestinal conditions, especially the highly acidic environment in the stomach and bile salts in the intestine. In addition, to overcome the challenging conditions, an ideal delivery of probiotics requires the on-demand release of probiotics upon environmental response. Herein, a novel nitroreductase (NTR) labile peptidic hydrogel based on supramolecular self-assembly is demonstrated. The efficient encapsulation of typical probiotic Escherichia coli Nissle 1917 (EcN) into supramolecular assemblies yielded a probiotic-loaded hydrogel (EcN@Gel). Such a hydrogel adequately protected EcN to improve its viability against harsh acid and bile salt environments during oral delivery. The upregulated NTR in the intestinal tract triggered the disassembly of the hydrogel and accomplished the controlled release of EcN locally. In ulcerative colitis (UC)-bearing mice, EcN@Gel showed significantly enhanced therapeutic efficacy by downregulating proinflammatory cytokines and repairing the intestinal barrier. Moreover, EcN@Gel remolded the gut microbiome by increasing the diversity and abundance of indigenous probiotics, contributing to ameliorated therapies of IBDs. The NTR-labile hydrogel provided a promising platform for the on-demand delivery of probiotics into the intestinal tract.

Development and evaluation of a fish feed mixture containing the probiotic Lactiplantibacillus plantarum prepared using an innovative pellet coating method

Introduction

Due to the intensification of fish farming and the associated spread of antimicrobial resistance among animals and humans, it is necessary to discover new alternatives in the therapy and prophylaxis of diseases. Probiotics appear to be promising candidates because of their ability to stimulate immune responses and suppress the growth of pathogens.

Methods

The aim of this study was to prepare fish feed mixtures with various compositions and, based on their physical characteristics (sphericity, flow rate, density, hardness, friability, and loss on drying), choose the most suitable one for coating with the selected probiotic strain Lactobacillus plantarum R2 Biocenol™ CCM 8674 (new nom. Lactiplantibacillus plantarum). The probiotic strain was examined through sequence analysis for the presence of plantaricin- related genes. An invented coating technology based on a dry coating with colloidal silica followed by starch hydrogel containing L. plantarum was applied to pellets and tested for the viability of probiotics during an 11-month period at different temperatures (4°C and 22°C). The release kinetics of probiotics in artificial gastric juice and in water (pH = 2 and pH = 7) were also determined. Chemical and nutritional analyses were conducted for comparison of the quality of the control and coated pellets.

Results and discussion

The results showed a gradual and sufficient release of probiotics for a 24-hour period, from 10⁴ CFU at 10 mi up to 10⁶ at the end of measurement in both environments. The number of living probiotic bacteria was stable during the whole storage period at 4°C (10⁸), and no significant decrease in living probiotic bacteria was observed. Sanger sequencing revealed the presence of plantaricin A and plantaricin EF. Chemical analysis revealed an increase in multiple nutrients compared to the uncoated cores. These findings disclose that the invented coating method with a selected probiotic strain improved nutrient composition and did not worsen any of the physical characteristics of pellets. Applied probiotics are also gradually released into the environment and have a high survival rate when stored at 4°C for a long period of time. The outputs of this study confirm the potential of prepared and tested probiotic fish mixtures for future use in in vivo experiments and in fish farms for the prevention of infectious diseases.

Evaluation of Surface Modified Live Biotherapeutic Products for Oral Delivery

Live biotherapeutic products (LBPs), including symbiotic and genetically engineered bacteria, are a promising class of emerging therapeutics that are widely investigated both preclinically and clinically for their oral delivery to the gastrointestinal (GI) tract. One emergent delivery strategy involves the direct functionalization of LBP surfaces through noncovalent or covalent modifications to control LBP interactions with the GI microenvironment, thereby improving their viability, attachment, or therapeutic effect. However, unlike other therapeutic modalities, LBPs are living organisms which present two unique challenges for surface modifications: (1) this approach can directly interfere with key LBP biological processes (e.g., colonization, metabolite secretion) and (2) modification can be variable due to the dynamic nature of LBP surfaces. Collectively, these factors remain uncharacterized as they relate to the oral delivery of LBPs. Herein, we leverage our previously reported surface modification platform, which enables LBP surface-presentation of targeting ligands, to broadly evaluate and characterize surface modifications on LBPs. Specifically, we evaluate how LBP growth affects the dilution of surface-presented targeting ligands and the subsequent loss of specific target attachment over time. Next, we describe key surface modification parameters (e.g., concentration, residence time) that can be optimized to facilitate LBP target attachment. We then characterize how bioconjugation influences the suitability of LBPs for oral delivery by evaluating their growth, viability, storage, toxicity against mammalian cells, and in vivo colonization. Broadly, we describe key parameters that influence the performance of surface modified LBPs and subsequently outline an experimental pipeline for characterizing and evaluating their suitability for oral delivery.

Benefits of fermented synbiotic soymilk containing Lactobacillus acidophilus, Bifidobacterium lactis, and inulin towards lead toxicity alleviation

This study aims to evaluate the effect of fermented synbiotic soy milk containing Lactobacillus acidophilus, Bifidobacterium lactis, and inulin on a series of hematological and oxidative stress parameters, as well as serum lead levels in rats. In this study, 56 male Sprague-Dawley rats were randomly assigned to assess probiotics (L. acidophilus or B. lactis), probiotics with prebiotics (i.e., inulin), and the corresponding controls. Several hematologic parameters (red blood cell (RBC)), hematocrit (HCT) and hemoglobin (Hgb)), serum lead levels, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) presence was measured to evaluate changes on day 42. Although a significant difference was observed in serum lead levels, there were no significant changes in hematological and oxidative stress parameters between the study groups. In conclusion, this study demonstrates that administering synbiotic fermented soy milk containing the probiotic Lactobacillus acidophilus and the prebiotic inulin may significantly improve serum lead levels in rats.

Probiotic Properties and Antioxidant Activity In Vitro of Lactic Acid Bacteria

The properties of probiotics such as lactic acid bacteria (LAB) have been widely studied over the last decades. In the present study, four different LAB species, namely Lactobacillus gasseri ATCC 33323, Lacticaseibacillus rhamnosus GG ATCC 53103, Levilactobacillus brevis ATCC 8287, and Lactiplantibacillus plantarum ATCC 14917, were investigated in order to determine their ability to survive in the human gut. They were evaluated based on their tolerance to acids, resistance to simulated gastrointestinal conditions, antibiotic resistance, and the identification of genes encoding bacteriocin production. All four tested strains demonstrated high resistance to simulated gastric juice after 3 h, and the viable counts revealed declines in cell concentrations of less than 1 log cycle. L. plantarum showed the highest level of survival in the human gut, with counts of 7.09 log CFU/mL. For the species L. rhamnosus and L. brevis, the values were 6.97 and 6.52, respectively. L. gasseri, after 12 h, showed a 3.96 log cycle drop in viable counts. None of the evaluated strains inhibited resistance to ampicillin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, or chloramphenicol. With regard to bacteriocin genes, the Pediocin PA gene was identified in Lactiplantibacillus plantarum ATCC 14917, Lacticaseibacillus rhamnosus GG ATCC 53103, and Lactobacillus gasseri ATCC 33323. The PlnEF gene was detected in Lactiplantibacillus plantarum ATCC 14917 and Lacticaseibacillus rhamnosus GG ATCC 53103. The Brevicin 174A and PlnA genes were not detected in any bacteria. Moreover, the potential antioxidant activity of LAB's metabolites was evaluated. At the same time, the possible antioxidant activity of metabolites of LAB was first tested using the free radical DDPH^• (a, a-Diphenyl-β-Picrylhydrazyl) and then evaluated with regard to their radical scavenging activity and inhibition against peroxyl radical induced DNA scission. All strains showed antioxidant activity; however, the best antioxidant activity was achieved by L. brevis (94.47%) and L. gasseri (91.29%) at 210 min. This study provides a comprehensive approach to the action of these LAB and their use in the food industry.

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.

Using bugs as drugs: administration of bacteria-related microbes to fight cancer

Driven by the advancement of microbiology and cancer biology, bioengineering of bacteria-related microbes has demonstrated great potential in targeted cancer therapy. Presently, the major administration routes of bacteria-related microbes for cancer treatment include intravenous injection, intratumoral injection, intraperitoneal injection, and oral delivery. Administration routes of bacteria play a key role in anticancer therapeutic efficacy since different delivery approaches might exert an anticancer effect through diverse mechanisms. Herein, we provide an overview of the primary routes of bacteria administration as well as their advantages and limitations. Furthermore, we discuss that microencapsulation can overcome the current challenges of direct administration of free bacteria. We also review the latest advancements in combining functional particles with engineered bacteria to fight against cancer, which can be further coupled with conventional anticancer therapies to improve the therapeutic effect. Eventually, we highlight the application prospect of bioprinting in cancer bacteriotherapy, which enables the long-term sustained delivery and individualized dose regimen, representing a new paradigm for personalized cancer treatment.

Bacteria-Induced Colloidal Encapsulation for Probiotic Oral Delivery

Probiotic oral delivery has crucial implications in biomedical engineering, but its oral bioavailability remains unsatisfactory because of the limited survival and colonization of probiotics in the harsh gastrointestinal tract. Here, a bacteria-induced encapsulation strategy is achieved by assembling metastable colloids to enhance the oral bioavailability of probiotics. The colloids (NTc) composed of amino-modified poly-β-cyclodextrin and tannic acid are formed based on the balance of host-guest interaction-driven attraction and electrostatic repulsion between colloids. Negatively charged probiotics electrostatically attract positively charged NTc to break the balance and induce further assembly surrounding the probiotics. Through a facile one-step mixing, 97% of bacteria are rapidly encapsulated into NTc shells within 10 s, with a high utilization rate of feeding colloids of 91%. More importantly, we show that the compact, thick, and positively charged NTc shells synergistically endow the encapsulated probiotics with strong resistance against simulated gastric fluid with an excellent survival rate of up to 19%, 7500 times superior to the commercial enteric material L100. Moreover, owing to the dynamically noncovalent and self-adaptive nature of host-guest interactions, NTc shells support the proliferation of the encapsulated EcN comparable with that of the naked EcN. In vitro and in vivo experiments also confirm that the NTc-encapsulated probiotics possess durable intestinal adhesion, continuous proliferation activity, enhanced oral bioavailability, good oral biosafety, and excellent therapeutic efficacy in a colitis mouse model. This facile bacteria-induced colloidal encapsulation strategy may extend to various microbes as oral bioagents for treating various diseases.

The Effect of Encapsulating a Prebiotic-Based Biopolymer Delivery System for Enhanced Probiotic Survival

Orally delivered probiotics must survive transit through harsh environments during gastrointestinal (GI) digestion and be delivered and released into the target site. The aim of this work was to evaluate the survivability and delivery of gel-encapsulated Lactobacillus rhamnosus GG (LGG) to the colon. New hybrid symbiotic beads alginate/prebiotic pullulan/probiotic LGG were obtained by the extrusion method. The average size of the developed beads was 3401 µm (wet), 921 µm (dry) and the bacterial titer was 109 CFU/g. The morphology of the beads was studied by a scanning electron microscope, demonstrating the structure of the bacterial cellulose shell and loading with probiotics. For the first time, we propose adding an enzymatic extract of feces to an artificial colon fluid, which mimics the total hydrolytic activity of the intestinal microbiota. The beads can be digested by fecalase with cellulase activity, indicating intestinal release. The encapsulation of LGG significantly enhanced their viability under simulated GI conditions. However, the beads, in combination with the prebiotic, provided greater protection of bacteria, enhancing their survival and even increasing cell numbers in the capsules. These data suggest the promising prospects of coencapsulation as an innovative delivery method based on the inclusion of probiotic bacteria in a symbiotic matrix.

Electrospinning Living Bacteria: A Review of Applications from Agriculture to Health Care

Living bacteria are used in biotechnologies that lead to improvements in health care, agriculture, and energy. Encapsulating bacteria into flexible and modular electrospun polymer fabrics that maintain their viability will further enable their use. This review will first provide a brief overview of electrospinning before examining the impact of electrospinning parameters, such as precursor composition, applied voltage, and environment on the viability of encapsulated bacteria. Currently, the use of nanofiber scaffolds to deliver live probiotics into the gut is the most researched application space; however, several additional applications, including skin probiotics (wound bandages) and menstruation products have also been explored and will be discussed. The use of bacteria-loaded nanofibers as seed coatings that promote plant growth, for the remediation of contaminated wastewaters, and in energy-generating microbial fuel cells are also covered in this review. In summary, electrospinning is an effective method for encapsulating living microorganisms into dry polymer nanofibers. While these living composite scaffolds hold potential for use across many applications, before their use in commercial products can be realized, numerous challenges and further investigations remain.