Encapsulated probiotic cells: Relevant techniques, natural sources as encapsulating materials and food applications – A narrative review

Encapsulation of a Probiotic Bacterial Strain in a Biocompatible Iron(III) Fumarate Matrix

The encapsulation of bacteria in metal-organic frameworks (MOFs) is being studied for use in biomedicine and bioremediation. However, biocompatibility could be improved, as much of the research focuses on ZIF-8 and Escherichia coli. MIL-88A, composed of fumaric acid and iron, offers a safer alternative. This study investigates encapsulation of the probiotic strain Lactiplantibacillus plantarum 299v in a nanocrystalline matrix via a simple one-pot synthesis. The encapsulated bacteria show improved stability in saline, lysozyme and pepsin compared to uncoated cells. These findings highlight the potential of the iron(III) fumarate matrix for bacterial protection and controlled release for biological applications.

Prebiotics empower probiotics with gastrointestinal stress resistance for colon-targeted release to synergistically alleviate colitis

Oral administration of probiotics holds promise for alleviating ulcerative colitis (UC), yet their efficacy is inevitably compromised by the hostile gastrointestinal (GI) environment. Here, we devised a strategy by coating β-glucan (GN) prebiotic onto the surface of Lactobacillus plantarum (Lp) probiotic at the single-cell level (Lp@CGN) based on bioorthogonal chemistry in a layer-by-layer manner. This achieved to form a firm, dense, and multifunctional GN-based "armor" with advances of superior protective properties, colon-targeted degradation, and prebiotic benefits. Under the protection of the prebiotic-based "armor", Lp@CGN exhibited a notable 276-fold increase in the survival rate compared to naïve Lp after exposure to whole GI conditions. Upon reaching the colon, the "armor" was metabolized into short-chain fatty acids (SCFAs) by gut microbiota, facilitating the timely release of Lp within colon, thereby achieving a synergistic treatment effect due to sustained SCFAs generation and Lp liberation. As a result, oral administration of Lp@CGN efficiently realized the alleviation of UC in both preventative and therapeutic models through restoring intestinal mucosal barriers, positively regulating inflammatory cytokines, renovating the dysbiosis of gut microbiota, and promoting SCFAs production. In sum, our strategy marks the reconstruction of probiotics with chemical tools, offering useful insights into powering probiotics for disease treatment.

Synbiotic Microencapsulation of Lactobacillus Strains from Mexican Fermented Beverages for Enhanced Probiotic Functionality

Synbiotics, which combine probiotics and prebiotics, represent an innovative approach to developing functional foods with enhanced health benefits compared to their individual components. This study focuses on the production of synbiotics through the microencapsulation of Lactobacillus strains isolated from traditional Mexican fermented beverages, contributing to the advancement of technologies for functional food development. Three Lactobacillus strains (Lacticaseibacillus rhamnosus LM07, Lactiplantibacillus plantarum LM19, and Levilactobacillus brevis LBH1070) were microencapsulated by spray-drying using a mixture of maltodextrin and gum arabic as wall materials and inulin as a prebiotic. The microencapsulation process achieved high survival rates (>90%), low moisture content (~5%), and low water activity (~0.3), ensuring long-term stability. Notably, the microencapsulated strains demonstrated improved tolerance to gastrointestinal conditions, enhanced adhesion properties, and increased antioxidant activity compared to non-microencapsulated strains. These results highlight the potential of microencapsulation as an innovative technology not only to preserve but also to enhance probiotic properties, facilitating the development of functional foods with improved health-promoting properties, extended shelf life, and stability at room temperature.

Freeze drying microencapsulation using whey protein, maltodextrin and corn powder improved survivability of probiotics during storage

Various studies demonstrated that probiotics play important roles in maintaining the balance of microorganisms in the body. Some strains produce bile salt hydrolase enzyme (BSH), which is an indirect mechanism for lowering cholesterol. BSH-producing probiotics as a supplement might be an alternative way to help reducing cholesterol in the body. The aim of this study was to investigate the effects of different microcapsule formulations with selected vegetable powders on growth characteristics of 3 Thai probiotic strains, Lactobacillus gasseri TM1, Lacticaseibacillus rhamnosus TM7, and L. rhamnosus TM14. Probiotics were cultured in MRS broth supplemented with 5 vegetable powders. Corn powder significantly increased growth rate of probiotics from 109 to 1012 CFU/ml. Therefore, different microcapsule formulations by Maillard reaction of whey protein isolate and maltodextrin mixed with and without corn powder were studied. The results showed that probiotic microcapsules formulated with corn powder significantly effectively sustained probiotic viability under gastrointestinal and storage conditions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01706-w.

Influence of the addition of gum arabic and xanthan gum in the preparation of sodium alginate microcapsules coated with chitosan hydrochloride on the survival of Lacticaseibacillus rhamnosus GG

The microencapsulation of Lactocaseibacillus rhamnosus GG in a matrix of sodium alginate, xanthan gum, gum arabic and chitosan hydrochloride is a promising strategy for protecting this probiotic during passage through the gastrointestinal tract. This study evaluated the influence on the viability of Lactocaseibacillus rhamnosus GG encapsulated with these polymers by external ionic gelation with vibratory extrusion and the microcapsules that showed the best results of capsulation efficiency, viability, size and morphology were analyzed by Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA) and exposure to environmental stress conditions and gastrointestinal simulation. The result revealed encapsulation efficiency values above 95 % for all formulations and survival rate higher than 6 log CFU/mL for most analyzed groups. The lowest viability values after storage at 7 °C were presented by formulations prepared with Arabic Gum and Xanthan, as well as the largest sizes, expansion index, and physical integrity loss of the microcapsules. Sodium alginate microcapsules coated with chitosan hydrochloride demonstrated enhanced viability during storage at 7 °C and 25 °C, alongside superior cell survival rates under environmental stress conditions and simulated gastrointestinal environments indicating that sodium alginate-chitosan hydrochloride microparticles are expected to become an ideal carrier for the actives encapsulation in pharmaceutical and food and industries.

A Closer Look at the Potential Mechanisms of Action of Protective Agents Used in the Drying of Microorganisms: A Review

Yeast, bacteria and sourdough are widely used in our daily lives, yet their drying and storage remains a significant challenge. A variety of techniques are used to improve the resistance of cells to thermal, dehydration, oxidative and osmotic stresses, which can occur at different stages of the process. The addition of protective agents prior to drying is a commonly used method, but the mechanisms that may lead to a change in viability following the addition of these agents, or more generally, the interaction between a protective agent and the drying process, are not yet fully understood. This review outlines seven main potential mechanisms, as highlighted in the literature, which can lead to internal or external modifications of the cells. The mechanisms in question are change of membrane fluidity, accumulation of compounds for osmoregulation, prior osmotic dehydration, prevention of oxidation, coating or encapsulation, enhancement in thermal resistance and change in drying kinetics. A comprehensive explanation of these mechanisms is provided. This review also highlights the connection between the mechanisms and the influence of the stresses occurring during drying and storage, which depend on the drying technique used and the operating conditions, the strains and the protective agents involved, on the importance of the different protection mechanisms. By gaining a deeper understanding of the mechanisms of action of protective agents, strategies to improve the quality of the microorganisms obtained after drying can be developed. One such strategy would be to combine several agents to achieve a synergistic effect.

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.

Improving the physical stability of Lactobacillus plantarum LP90 during storage by mixing carboxymethylated dextran-whey protein conjugates and small-molecule sugars

To explore the effect of small-molecule sugars on the physical stability of microcapsules and enhance probiotic preservation, carboxymethylated dextran and whey protein conjugate (WP-CD5d) by Maillard reaction were used as the wall material. Trehalose, lactose, and sucrose were used as lyoprotectants to encapsulate Lactobacillus plantarum LP90 (LP90) during storage, forming microcapsules labeled as WP-CD5dH, WP-CD5dR, and WP-CD5dZ, respectively. WP-CD5dH and WP-CD5dR exhibited the highest viability after freeze-drying, with survival rates of 97.8 % ± 0.9 % and 98.5 % ± 0.5 % respectively. LP90 microcapsules exhibited strong resistance to simulated gastrointestinal fluid over 5 h. The Guggenheim-Anderson-de Boer (GAB) and Gordon-Taylor model showed that WP-CD5dH had the best reduction in water plasticization (k was 4.0). 1H NMR spectra confirmed that WP-CD5dH exhibited the lowest molecular mobility. Furthermore, the storage experiment showed that WP-CD5dH provided the best protection for LP90 at 11 % RH, with a K value of 0.021. These results suggest that the probiotic mechanism of small-molecule sugars involves forming intermolecular forces with WP-CD5d, which helps to maintain the glassy state.

Harnessing the polysaccharide production potential to optimize and expand the application of probiotics

Certain probiotic microorganisms can synthesize important bioproducts, including polysaccharides as components of cellular structure or extracellular matrix. Probiotic-derived polysaccharides have been widely applied in food, pharmaceutical, and medical fields due to their excellent properties and biological activities. The development of polysaccharide production potential has become a driving force for facilitating biotechnological applications of probiotics. Based on technical advances in synthetic biology, significant progress has recently been made in engineering probiotics with efficient biosynthesis of polysaccharides. Herein, this review summarizes probiotics chassis and genetic tools used for polysaccharide production. Then, probiotic polysaccharides and relevant biosynthesis mechanisms are also clearly described. Next, we introduce strategies for preparing high-yield, controllable molecular weight or non-native polysaccharides by adjusting metabolic pathways and integrating expression elements in probiotics. Finally, some prospective and well-established contributions of exogenous and in situ polysaccharides in probiotics' stability, bioactivity, and therapeutic effects are presented. Our viewpoints on advancing the efficient biomanufacturing of valuable biopolymers in probiotics and engineering probiotics with customized features are provided to exploit probiotics' industrial and biomedical applications.

Probiotics and Food Bioactives: Unraveling Their Impact on Gut Microbiome, Inflammation, and Metabolic Health

This review paper delves into the role of probiotics and food bioactives in influencing gut health and overall well-being, within the context of probiotics and food bioactives, emphasizing their roles in modulating inflammation, gut microbiota, and metabolic health. Probiotics are defined as live microorganisms that confer health benefits to the host, primarily through their impact on the gut microbiome; a complex community of microorganisms crucial for maintaining health. The review aims to elucidate how probiotics, incorporated into both traditional and modern food systems, can enhance gut health and address metabolic disorders. It examines the types of probiotics present in various foods and their mechanisms of action, including their effects on immune function and metabolic health. By exploring the links between probiotics and health outcomes such as digestive health, immune support, and mental health, the review identifies specific conditions where probiotics show significant promise. Hurldes such as inconsistencies in research findings, variability in probiotic strains, and dosages are addressed. The paper also suggests future research directions, including the potential for personalized probiotic interventions. The review concludes by summarizing key findings and emphasizing the critical role of probiotics in food systems for promoting overall health and mitigating metabolic diseases.

Advances in bio-polymer coatings for probiotic microencapsulation: chitosan and beyond for enhanced stability and controlled release

This review paper analyzes recent advancements in bio-polymer coatings for probiotic microencapsulation, with a particular emphasis on chitosan and its synergistic combinations with other materials. Probiotic microencapsulation is essential for protecting probiotics from environmental stresses, enhancing their stability, and ensuring effective delivery to the gut. The review begins with an overview of probiotic microencapsulation, highlighting its significance in safeguarding probiotics through processing, storage, and gastrointestinal transit. Advances in chitosan-based encapsulation are explored, including the integration of chitosan with other bio-polymers such as alginate, gelatin, and pectin, as well as the application of nanotechnology and innovative encapsulation techniques like spray drying and layer-by-layer assembly. Detailed mechanistic insights are integrated, illustrating how chitosan influences gut microbiota by promoting beneficial bacteria and suppressing pathogens, thus enhancing its role as a prebiotic or synbiotic. Furthermore, the review delves into chitosan's immunomodulatory effects, particularly in the context of inflammatory bowel disease (IBD) and autoimmune diseases, describing the immune signaling pathways influenced by chitosan and linking gut microbiota changes to improvements in systemic immunity. Recent clinical trials and human studies assessing the efficacy of chitosan-coated probiotics are presented, alongside a discussion of practical applications and a comparison of in vitro and in vivo findings to highlight real-world relevance. The sustainability of chitosan sources and their environmental impact are addressed, along with the novel concept of chitosan's role in the gut-brain axis. Finally, the review emphasizes future research needs, including the development of personalized probiotic therapies and the exploration of novel bio-polymers and encapsulation techniques.

Different polysaccharide-enhanced probiotic and polyphenol dual-functional factor co-encapsulated microcapsules demonstrate acute colitis alleviation efficacy and food fortification

Probiotics and polyphenols have multiple bioactivities, and developing co-encapsulated microcapsules (CM) is a novel strategy to enhance their nutritional diversity. However, the development of CMs is challenged by complicated processing, single types, and unclear in vivo effects and applications. In this study, the co-microencapsulations of polyphenol and probiotic were constructed using pectin, alginate (WGCA@LK), and Fu brick tea polysaccharides (WGCF@LK), respectively, with chitosan-whey isolate proteins by layer-by-layer coacervation reaction, and their protective effects, in vivo effectiveness, and application potential were evaluated. WGCA@LK improved the encapsulation rate of polyphenols (42.41 %), and remained high viability of probiotics after passing through gastric acidic environment (8.79 ± 0.04 log CFU/g) and storage for 4 weeks (4.59 ± 0.06 log CFU/g). WGCF@LK exhibited the highest total antioxidant activity (19.40 ± 0.25 μmol/mL) and its prebiotic activity removed the restriction on probiotic growth. WGCA@LK showed strong in vitro colonic adhesion, but WGCF@LK promoted in vivo retention of probiotics at 48 h. WGCF@LK showed excellent anti-inflammatory effects and alleviated symptoms of acute colitis in mice. These findings provide unique insights into the fortification of probiotic-polyphenol CMs by different polysaccharides and the development of novel health foods with rich functional hierarchies and superior therapeutic effects.

Development of whey protein beverage incorporating encapsulated probiotic strain Lactiplantibacillus rhamnosus NCDC 347 and its physico-chemical characteristics

In the present study, encapsulated strain Lactiplantibacillus rhamnosus NCDC 347 was used to prepare a novel whey protein-based beverage. The encapsulation process utilized skimmed milk powder matrix and evaluated strain viability, physico-chemical properties, sensory assessment, and shelf-life stability. Encapsulated L. rhamnosus NCDC 347 within skim milk powder maintained viability at 8.0 log CFU/g, forming spherical microcapsules with 1-12 µm concavities. Probiotic addition to whey protein beverages maintained pH and acidity within desired ranges. Physico-chemical analysis showed protein content of 8.71 ± 0.21 % to 10.05 ± 0.42 %, fat content of 0.56 ± 0.24 % to 0.67 ± 0.13 %, viscosity of 5.14 pa/s, and total soluble solids (TSS) of 14.42 ± 0.31 to 16.16 ± 0.23° Brix. The shelf-life study revealed that the beverage remained stable for up to 90 days with no significant changes (p > 0.05) in sensory analysis. The sensory analysis scored the test sample's acceptability at 7.3 ± 0.41. The protein-rich probiotic drink exhibited favorable sensory qualities. Overall, incorporating encapsulated probiotic strain L. rhamnosus NCDC 347 into whey protein beverages could address daily protein requirements and enhance health.

Utilization of diverse probiotics to create human health promoting fatty acids: A review

Many probiotics produce functional lipids with health-promoting properties, such as short-chain fatty acids, linoleic acid and omega-3 fatty acids. They have been shown to maintain gut health, strengthen the intestinal barrier, and have anti-inflammatory and antioxidant effects. In this article, we provide an up-to-date review of the various functional lipids produced by probiotics. These probiotics can be incorporated into foods, supplements, or pharmaceuticals to produce these functional lipids in the human colon, or they can be used in industrial biotechnology processes to generate functional lipids, which are then isolated and used as ingredients. We then highlight the different physiological functions for which they may be beneficial to human health, in addition to discussing some of the challenges of incorporating probiotics into commercial products and some potential solutions to address these challenges. Finally, we highlight the importance of testing the efficacy and safety of the new generation of probiotic-enhanced products, as well as the great potential for the marketization of related products.

Wood hemicelluloses as protective materials for preserving the viability of probiotic Lacticaseibacillus rhamnosus GG during spray drying

Wood hemicelluloses from forest industry side-streams are promising economic and sustainable alternatives for encapsulating bioactive compounds. This study explores their suitability for probiotic encapsulation, specifically for maintaining cell viability and structure. The ability of galactoglucomannans (GGM) and glucuronoxylans (GX) to support the survival of Lacticaseibacillus rhamnosus GG (LGG) during spray drying at solid feed concentrations of 15 and 20 % and inlet air temperatures of 105 and 140 °C (outlet air temperature of 50 °C) was investigated and compared to the results obtained using maltodextrin (MD). Across all investigated conditions, LGG survival rates exceeded 85 % (>107 cfu/g) in GX and GGM microcapsule powders, which similar to that in MD microcapsules despite the differences in pH, particle size, and viscosity of their feed dispersions. The GX microcapsules demonstrated the highest process yield (50-58 %), followed by MD (39-51 %). All the microcapsule powders exhibited an amorphous structure consisting of spherical particles with an average diameter of 10 μm, sufficient for LGG accommodation. Atomic force microscopy analysis confirmed the encapsulation of LGG cells within microcapsules with intact rod-shaped chains post-spray drying. Overall, the spray-dried microencapsulation of probiotics using wood hemicelluloses maintains high probiotic viability and offers an eco-friendly, cost-effective alternative to traditional materials.

Advances in Yeast Probiotic Production and Formulation for Preventative Health

The use of probiotics has been gaining popularity in terms of inclusion into human diets over recent years. Based on properties exerted by these organisms, several benefits have been elucidated and conferred to the host. Bacteria have been more commonly used in probiotic preparations compared to yeast candidates; however, yeast exhibit several beneficial properties, such as the prevention and treatment of diarrhea, the production of antimicrobial agents, the prevention of pathogen adherence to intestinal sites, the maintenance of microbial balance, the modulation of the immune system, antibiotic resistance, amongst others. Saccharomyces boulardii is by far the most studied strain; however, the potential for the use of other yeast candidates, such as Kluyveromyces lactis and Debaryomyces hansenii, amongst others, have also been evaluated in this review. Furthermore, a special focus has been made regarding the production considerations for yeast-based probiotics and their formulation into different delivery formats. When drafting this review, evidence suggests that the use of yeasts, both wild-type and genetically modified candidates, can extend beyond gut health to support skin, the respiratory system, and overall immune health. Hence, this review explores the potential of yeast probiotics as a safe, effective strategy for preventative health in humans, highlighting their mechanisms of action, clinical applications, and production considerations.

Encapsulation of Lactiplantibacillus plantarum probiotics through cross-linked chitosan and casein for improving their viability, antioxidant and detoxification

In the present study, encapsulation of Lactiplantibacillus plantarum (L.p) was performed using chitosan and casein through calcium phosphate intercrossing. Chitosan and casein both considered as non-toxic and biocompatible food derived components with intrinsic antioxidant properties. Layer by layer strategy was performed for deposition of modified cross-linked chitosan along with casein as the novel protective layers on the surface of probiotics. After confirmation of successful encapsulation, the viability and antioxidant activity of encapsulated L.p was evaluated. The results showed enhanced survival and antioxidant activity of encapsulated L.p compared to free bacteria in simulated digestive conditions. The survival of free and encapsulated L.p was respectively 1.38 ± 0.29 log cfu/ml and 6.99 ± 0.12 log cfu/ml in SGF and 8.54 ± 0.05 log cfu/ml and 7.25 ± 0.23 log cfu/ml in SIJ after 2 h of incubation. HPLC analysis was also used to investigate the detoxification activity of probiotics toward Aflatoxin M1 and obtained results showed encapsulated bacteria could significantly reduce aflatoxin M1 (68.44 ± 0.5 %) compared to free bacteria (43.76 ± 0.54 %). The results of this research suggest that the chitosan/casein mediated encapsulation of L.p with layer-by-layer technology is an effective method to improve the survival and antioxidant properties of probiotics with enhanced detoxification of AFM1.

Alginate Capsules: Versatile Applications and Production Techniques

Alginate is a natural polysaccharide commonly obtained from brown algae and is usually used in the food industry as an additive, specifically as a thickening, gelling, and emulsifying agent. Due to its polyanionic nature, it can crosslink in the presence of divalent or trivalent cations. This crosslinking process involves the formation of chemical bonds between the carboxylic groups of parallel chains, resulting in a solid structure. In this way, compounds of interest can be enclosed in a capsule or a bead. Thanks to this ability, possible applications of alginate capsules are countless: it is possible to range from the pharmaceutical to the nutritional fields, from the agri-food industry to the textile or cosmetic sectors. These capsules can protect the encapsulated ingredients, promote their delivery or controlled release, or be imagined as small-scale reactors. The present review describes the main techniques used to produce alginate capsules, and several examples of possible application fields are shown.

Comparative efficiency of Geotrichum candidum microcapsules prepared with alginate and in combination with other polymers: In vitro evaluation

Microencapsulation is utilized to protect probiotics, such as Geotrichum candidum, ensuring their survival, stability, and targeted release. The encapsulation efficiency depends on factors such as the type and concentration of the polymers and the encapsulation method. In this study, G. candidum was encapsulated using alginate (Alg) combined with starch (AlgS) or xanthan (Alg-X) and coated with chitosan aand chitosan nanoparticles (AlgC, Alg-S-C, Alg-X-C, Alg-CN, Alg-S-CN, and Alg-X-CN) using a simple extrusion technique. The structural characteristics and surface morphology of the microcapsules were analyzed using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Encapsulation efficiency (EE) and pH and temperature tolerances were assessed using in vitro assays. SEM results showed that the Alg-CN microcapsules were notably spherical and smooth, in contrast to the irregular and rough textures of the uncoated forms. Notably, Alg-CN exhibited the highest EE (99.3 %), followed by Alg-C (96.6 %) and Alg-X-CN (96.03 %). Moreover, chitosan-coated microcapsules, particularly Alg-CN, demonstrated superior viability at various pH levels and after exposure to 60 °C, along with extended shelf life at room temperature and 4 °C. These findings suggest that a 2 % alginate and 0.4 % chitosan combination is optimal for preserving G. candidum's viability in various applications.

Intestinal Delivery of Probiotics: Materials, Strategies, and Applications

Probiotics with diverse and crucial properties and functions have attracted broad interest from many researchers, who adopt intestinal delivery of probiotics to modulate the gut microbiota. However, the major problems faced for the therapeutic applications of probiotics are the viability and colonization of probiotics during their processing, oral intake, and subsequent delivery to the gut. The challenges of simple oral delivery (stability, controllability, targeting, etc.) have greatly limited the use of probiotics in clinical therapies. Nanotechnology can endow the probiotics to be delivered to the intestine with improved survival rate and increased resistance to the adverse environment. Additionally, the progress in synthetic biology has created new opportunities for efficiently and purposefully designing and manipulating the probiotics. In this article, a brief overview of the types of probiotics for intestinal delivery, the current progress of different probiotic encapsulation strategies, including the chemical, physical, and genetic strategies and their combinations, and the emerging single-cell encapsulation strategies using nanocoating methods, is presented. The action mechanisms of probiotics that are responsible for eliciting beneficial effects are also briefly discussed. Finally, the therapeutic applications of engineered probiotics are discussed, and the future trends toward developing engineered probiotics with advanced features and improved health benefits are proposed.

Selenized lactic acid bacteria microencapsulated by spray drying: A promising strategy for beef cattle feed supplementation

This study aimed to assess the technical feasibility of incorporating selenized Lactobacillus spp. microencapsulated via spray drying into cattle feed. Gum Arabic and maltodextrin were used as encapsulating agents. The encapsulation process was carried out with a drying air flow rate of 1.75 m3/min, inlet air temperature of 90°C, and outlet air temperature of 75°C. The viability of the encapsulated microorganisms and the technological characteristics of the obtained microparticles were evaluated. Microorganisms were incorporated into beef cattle feed to supplement their diet with up to 0.3 mg of Se per kilogram of feed. The encapsulated particles, consisting of a 50/50 ratio of gum Arabic/maltodextrin at a 1:20 proportion of selenized biomass to encapsulant mixture, exhibited superior technical viability for application in beef cattle feed. Supplemented feeds displayed suitable moisture, water activity, and hygroscopicity values, ensuring the preservation of viable microorganisms for up to 5 months of storage, with an approximate count of 4.5 log CFU/g. Therefore, supplementing beef cattle feed with selenized and microencapsulated lactic acid bacteria represents a viable technological alternative, contributing to increased animal protein productivity through proper nutrition.

Development, characterization and Lactobacillus plantarum encapsulating ability of novel C-phycocyanin-pectin-polyphenol based hydrogels

In this study, it was found that the enhancement in the viability of Lactobacillus plantarum under gastrointestinal conditions by encapsulating them within novel C-Phycocyanin-pectin based hydrogels (from 5.7 to 7.1 log/CFU). The hardness, the strength and the stability of the hydrogels increased when the protein concentration was increased. In addition, the addition of resveratrol (RES), and tannic acid (TA) could improve the hardness (from 595.4 to 608.3 and 637.0 g) and WHC (from 93.9 to 94.2 and 94.8 %) of the hydrogels. The addition of gallic acid (GA) enhanced the hardness (675.0 g) of the hydrogels, but the WHC (86.2 %) was decreased. During simulated gastrointestinal conditions and refrigerated storage, the addition of TA enhanced the viable bacteria counts (from 6.8 and 8.0 to 7.5 and 8.5 log/CFU) of Lactobacillus plantarum. Furthermore, TA and GA are completely encased by the protein-pectin gel as an amorphous state, while RA is only partially encased.

Improvement of Stress Resistance of Microencapsulated Lactobacillus plantarum by Emulsion Electrospinning

Probiotics have become increasingly recognized for their potential health-promoting properties; however, the viability of probiotics can be affected by storage and transportation processes as well as the stressful environment of the human digestive tract, preventing them from achieving effective concentration (107 CFU/mL). In this regard, the embedding technology of probiotics provides an effective protection method. Dextran-based water in water (W/W) emulsion loaded with Lactobacillus plantarum was used as spinning solution to prepare Lactobacillus plantarum-loaded electrospun fibers. The structure of the W/W emulsion and the electrospun fibers was charactered. Lactobacillus plantarum were uniformly embedded in the internal phase of the W/W emulsion and the loading efficiency was 9.70 ± 0.40 log CFU/g. After 240 min digestion in the gastrointestinal tract, and temperature treatment in 65 °C and 72 °C, the loaded probiotics maintained high activity. Even after 5 days of storage in room temperature and 4 °C, the loaded probiotic activity levels remained high, with counts >8 log CFU/g. These results suggest that probiotics encapsulated by emulsion electrospinning could be potentially delivered in a novel food delivery system used in the future food industry.

Core-shell nanofibers based on microalgae proteins/alginate complexes for enhancing survivability of probiotics

In this study, a novel one-step coaxial electrospinning process is employed to fabricate shell-core structure fibers choosing Chlorella pyrenoidosa proteins (CP) as the core material. These nanofibers, serving as the wall material for probiotic encapsulation, aimed to enhance the stability and antioxidant activity of probiotics in food processing, storage, and gastrointestinal environments under sensitive conditions. Morphological analysis was used to explore the beads-on-a-string morphology and core-shell structure of the electrospun fibers. Probiotics were successfully encapsulated within the fibers (7.97 log CFU/g), exhibiting a well-oriented structure along the distributed fibers. Compared to free probiotics and uniaxial fibers loaded with probiotics, encapsulation within microalgae proteins/alginate core-shell structure nanofibers significantly enhanced the probiotic cells' tolerance to simulated gastrointestinal conditions (p < 0.05). Thermal analysis indicated that microalgae proteins/alginate core-shell structure nanofibers displayed superior thermal stability compared to uniaxial fibers. The introduction of CP resulted in a 50 % increase in the antioxidant capacity of probiotics-loaded microalgae proteins/alginate nanofibers compared to uniaxial alginate nanofibers, with minimal loss of viability (0.8 log CFU/g) after 28 days of storage at 4 °C. In summary, this dual-layer carrier holds immense potential in probiotic encapsulation and enhancing their resistance to harsh conditions.

Encapsulation of Probiotics within Double/Multiple Layer Beads/Carriers: A Concise Review

An increased demand for natural products nowadays most specifically probiotics (PROs) is evident since it comes in conjunction with beneficial health effects for consumers. In this regard, it is well known that encapsulation could positively affect the PROs' viability throughout food manufacturing and long-term storage. This paper aims to analyze and review various double/multilayer strategies for encapsulation of PROs. Double-layer encapsulation of PROs by electrohydrodynamic atomization or electrospraying technology has been reported along with layer-by-layer assembly and water-in-oil-in-water (W1/O/W2) double emulsions to produce multilayer PROs-loaded carriers. Finally, their applications in food products are presented. The resistance and viability of loaded PROs to mechanical damage, during gastrointestinal transit and shelf life of these trapping systems, are also described. The PROs encapsulation in double- and multiple-layer coatings combined with other technologies can be examined to increase the opportunities for new functional products with amended functionalities opening a novel horizon in food technology.

Microbeads as carriers for Bacillus pumilus: a biofertilizer focus on auxin production

The study aimed to develop a solid biofertilizer using Bacillus pumilus, focusing on auxin production to enhance plant drought tolerance. Methods involved immobilising B. pumilus in alginate-starch beads, focusing on microbial concentration, biopolymer types, and environmental conditions. The optimal formulation showed a diameter of 3.58 mm ± 0.18, a uniform size distribution after 15 h of drying at 30 °C, a stable bacterial concentration (1.99 × 109 CFU g-1 ± 1.03 × 109 over 180 days at room temperature), a high auxin production (748.8 µg g-1 ± 10.3 of IAA in 7 days), and a water retention capacity of 37% ± 4.07. In conclusion, this new formulation of alginate + starch + L-tryptophan + B. pumilus has the potential for use in crops due to its compelling water retention, high viability in storage at room temperature, and high auxin production, which provides commercial advantages.

Fabrication of dry S/O/W microcapsule and its probiotic protection against different stresses

BACKGROUND

Encapsulation is commonly used to protect probiotics against harsh stresses. Thus, the fabrication of microcapsules with special structure is critical. In this work, microcapsules with the structure of S/O/W (solid-in-oil-in-water) emulsion were prepared for probiotics, with butterfat containing probiotics as the inner core and with whey protein isolate fibrils (WPIF) and antioxidants (epigallocatechin gallate, EGCG; glutathione, GSH) as the outer shell.

RESULTS

Based on the high viscosity and good emulsifying ability of WPIF, dry well-dispersed microcapsules were successfully prepared via the stabilization of the butterfat emulsion during freeze-drying with 30-50 g L-1 WPIF. WPIF, WPIF + EGCG, and WPIF + GSH microcapsules with 50 g L-1 WPIF protected probiotics very well against different stresses and exhibited similar inactivation results, indicating that EGCG and GSH exerted neither harm or protection on probiotics. This significantly reduced the harmful effects of antioxidants on probiotics. Almost all the probiotics survived after pasteurization, which was critical for the use of probiotics in other foods. The inactivation values of probiotics in microcapsules were around 1 log in simulated gastric juice (SGJ), about 0.5 log in simulated intestinal juice (SIJ), and around 1 log after 40 days of ambient storage.

CONCLUSION

Dry S/O/W microcapsule, with butterfat containing probiotics as the inner core and WPIF as the outer shell, significantly increased the resistance of probiotics to harsh environments. This work proposed a preparation method of dry S/O/W microcapsule with core/shell structure, which could be used in the encapsulation of probiotics and other bioactive ingredients.

Formulation, Characterization and In Vitro Evaluation of Mesalamine and Bifidobacterium bifidum Loaded Hydrogel Beads in Capsule System for Colon Targeted Delivery

Mesalamine is a first-line drug for the treatment of inflammatory bowel diseases. However, its premature release associated with marketed formulations leads to adverse effects like gastric trouble, vomiting, and diarrhoea. To minimize these side effects, colon-targeted drug delivery is essential. Besides conventional pharmacotherapy, bifidogenic probiotics with anti-inflammatory activity has been reported to elicit a significant impact on the remission of ulcerative colitis. Bifidogenic probiotics being acid-labile necessitate developing a gastro-resistant formulation for enhancing the delivery of viable cells to the colon. The present study was aimed at developing a fixed-dose unit dosage form of mucoadhesive hydrogel beads loaded with mesalamine and Bifidobacterium bifidum further encapsulated in Eudragit® capsules for the targeted drug delivery at colonic pH. The hydrogel beads were prepared by ionotropic gelation, with the effect of single and dual-crosslinking approaches on various formulation characteristics studied. Standard size 00 Eudragit® gastro-resistant capsules were prepared and the dried beads were filled inside the capsule shells. The formulation was then evaluated for various parameters, including physicochemical characterization, in vitro biocompatibility and anti-inflammatory activity. No interaction was observed between the drug and the polymers, as confirmed through FTIR, XRD, and DSC analysis. The mean particle size of the beads was ~ 457-485 µm. The optimized formulation showed a drug entrapment efficiency of 95.4 ± 2.58%. The Eudragit® capsule shells disintegrated in approximately 13 min at pH 7.4. The mucoadhesive hydrogel beads sustained the drug release above 18 h, with 50% of the drug released by the end of 12 h. The optimized formulation demonstrated significant (p < 0.05) gastro-resistance, biocompatibility, sustained drug release, cell viability, and anti-inflammatory activity.

Alginate-Based Encapsulation Fabrication Technique for Drug Delivery: An Updated Review of Particle Type, Formulation Technique, Pharmaceutical Ingredient, and Targeted Delivery System

Alginate is a natural biopolymer widely studied for pharmaceutical applications due to its biocompatibility, low toxicity, and mild gelation abilities. This review summarizes recent advances in alginate-based encapsulation systems for targeted drug delivery. Alginate formulations like microparticles, nanoparticles, microgels, and composites fabricated by methods including ionic gelation, emulsification, spray drying, and freeze drying enable tailored drug loading, enhanced stability, and sustained release kinetics. Alginate microspheres prepared by spray drying or ionic gelation provide gastric protection and colon-targeted release of orally delivered drugs. Alginate nanoparticles exhibit enhanced cellular uptake and tumor-targeting capabilities through the enhanced permeation and retention effect. Crosslinked alginate microgels allow high drug loading and controlled release profiles. Composite alginate gels with cellulose, chitosan, or inorganic nanomaterials display improved mechanical properties, mucoadhesion, and tunable release kinetics. Alginate-based wound dressings containing antimicrobial nanoparticles promote healing of burns and chronic wounds through sustained topical delivery. Although alginate is well-established as a pharmaceutical excipient, more extensive in vivo testing is needed to assess clinical safety and efficacy of emerging formulations prior to human trials. Future opportunities include engineered systems combining stimuli-responsiveness, active targeting, and diagnostic capabilities. In summary, this review discusses recent advances in alginate encapsulation techniques for oral, transdermal, and intravenous delivery, with an emphasis on approaches enabling targeted and sustained drug release for enhanced therapeutic outcomes.

Effects of Simulated Gastrointestinal Conditions on Combined Potentially Probiotic Limosilactobacillus fermentum 296, Quercetin, and/or Resveratrol as Bioactive Components of Novel Nutraceuticals

This study evaluated the effects of simulated gastrointestinal conditions (SGIC) on combined potentially probiotic Limosilactobacillus fermentum 296 (~ 10 log CFU/mL), quercetin (QUE, 160 mg), and/or resveratrol (RES, 150 mg) as the bioactive components of novel nutraceuticals. Four different nutraceuticals were evaluated during exposure to SGIC and analyzed the plate counts and physiological status of L. fermentum 296, contents and bioaccessibility of QUE and RES, and antioxidant capacity. Nutraceuticals with QUE and RES had the highest plate counts (4.94 ± 0.32 log CFU/mL) and sizes of live cell subpopulations (28.40 ± 0.28%) of L. fermentum 296 after SGIC exposure. An index of injured cells (Gmean index, arbitrary unit defined as above 0.5) indicated that part of L. fermentum 296 cells could be entered the viable but nonculturable state when the nutraceuticals were exposed to gastric and intestinal conditions while maintaining vitality. The nutraceuticals maintained high contents (QUE ~ 29.17 ± 0.62 and RES ~ 23.05 mg/100 g) and bioaccessibility (QUE ~ 41.0 ± 0.09% and RES ~ 67.4 ± 0.17%) of QUE and RES, as well as high antioxidant capacity (ABTS assay ~ 88.18 ± 1.16% and DPPH assay 75.54 ± 0.65%) during SGIC exposure, which could be linked to the protective effects on L. fermentum 296 cells. The developed nutraceuticals could cross along the gastrointestinal tract with high concentrations of functioning potentially probiotic cells and bioavailable phenolic compounds to exert their beneficial impacts on consumer health, being an innovative strategy for the co-ingestion of these bioactive components.

Regulation of Hepatocellular Cholesterol Metabolism By Lactobacillus Paracasei BY2 and Its Embedding Delivery

In this study, five strains of lactic acid bacteria (LAB) with excellent cholesterol-lowering ability were screened from fermented foods. The gastrointestinal stress resistance, intestinal adhesion, and bacteriostasis abilities were evaluated to obtain the best LAB. And then, high-cholesterol HepG2 cell model was further prepared to explore the cholesterol-lowering mechanism of the LAB. Finally, pH-sensitive hydrogel prepared by Millettia speciosa Champ. carboxymethyl cellulose and Millettia speciosa Champ. cellulose was first applied to the microencapsulation of LAB. As a result, Lactobacillus paracasei BY2 (LP-BY2) exhibited higher cholesterol-lowering activity, intestinal adhesion, and bacteriostasis abilities compared with other LAB. Furthermore, it was found that LP-BY2 could reduce the cholesterol level by regulating the expression of key genes that involved in cholesterol synthesis (HMGCR and SREBP-2), uptake (LDLR), and outflow (LXR-α, ABCA1, ABCG5, ABCG8, and CYP7A1) in liver. At the same time, microencapsulation significantly enhanced the survival rate and cholesterol-lowering ability of LP-BY2 after gastrointestinal digestion. This study will provide an available reference for the application of Lactobacillus in prevention and treatment of hypercholesterolemia.

Preparation and assessment of alginate-microencapsulated Trichoderma harzianum for controlling Sclerotinia sclerotiorum and Rhizoctonia solani on tomato

This study aimed to develop microencapsulation technology using alginate to improve the viability and performance of Trichoderma harzianum. The method of ionic gelation was used to prepare the microparticles, and the efficiency of encapsulation was estimated to be 99%. The average size of the prepared microspheres was 2600 μm (wet) and 1000 μm (dry). Scanning electron microscopy revealed that the microspheres were approximately spherical. Fourier transform infrared spectrophotometer analysis indicated an interaction between T. harzianum and the microspheres. The results of temperature resistance and light stability against ultraviolet radiation emphasized the positive impact of microencapsulation in improving the viability and resistance of T. harzianum compared to the non-microencapsulated state. The disease percentage of Rhizoctonia solani and Sclerotinia sclerotiorum in plants treated with microencapsulated T. harzianum microcapsules was 8.88 % and 20 % respectively, but in the control group was 73.33 % (p ≤ 0.05).

Survivability of probiotics in Pickering emulsion gels stabilized by salmon by-product protein / sodium alginate soluble complexes at neutral pH

Adequate amounts of live probiotics reaching the gut are necessary to maintain host health. However, the harsh environment during processing, the low pH of human gastric acid, and the high concentration of bile salts in the gut can significantly reduce survivability of probiotics. In this work, we propose a simple Pickering emulsion gels strategy to encapsulate Lactobacillus plantarum Lp90 into oil droplets filled in calcium alginate gels to improve its viability under pasteurization and gastrointestinal conditions. The emulsion gels were stabilized by the soluble complexes of salmon by-product protein (SP) and sodium alginate (ALG), and the aqueous phase was solidified by the addition of calcium. The interaction between SP and ALG and the effect of ALG concentration on emulsifying ability and emulsion stability were studied. The results from optical imaging, nuclear magnetic resonance, and rheological properties showed that the stability and viscosity of the emulsions gradually increased with the increased ALG concentration, while the droplet size of the emulsions and the content of free water in the system decreased significantly. Especially when the concentration of ALG was 1 %, the emulsion system was stable under the environment of high temperature and high ionic strength, and the water holding capacity was the highest. Through pasteurization and gastrointestinal digestion experiments, it was found that the survival rate of probiotics encapsulated in emulsion gels was significantly higher than that encapsulated in emulsions or hydrogels, which benefited from the dual action of oil droplets and calcium alginate gels network. These results provide a new strategy for the processing of probiotics and the high-value utilization of marine fish by-products.

Milk fat globule membrane protects Bifidobacterium longum ssp. infantis ATCC 15697 against bile stress by modifying global transcriptional responses

The milk fat globule membrane (MFGM) can protect probiotic bacteria from bile stress. However, its potential mechanism has not been reported. In this study, the viability, morphology and gene transcriptional response of Bifidobacterium longum ssp. infantis ATCC 15697 (BI_15697) stressed by bile salts with or without MFGM were investigated. It was shown that MFGM alleviated the reduction in BI_15697 population induced by 0.2% porcine bile stress and restored the population to the control levels. MFGM ameliorated the shrunken, fragmented appearance and irregular morphology of BI_15697 and maintained cell integrity disrupted by bile stress. RNA-sequencing results showed that MFGM increased transport of glucose and raffinose and decreased that of branched-chain amino acids (BCAA) in the presence of bile salts. MFGM stimulated the expression of genes involved in the synthesis of raffinose in galactose metabolism and the metabolism of BCAA, suggesting that MFGM stimulated the accumulation of raffinose and BCAA in the presence of bile. In addition, MFGM stimulated the expression of 2 bile efflux transporters under bile stress. Together, the multifactorial response helps BI_15697 excrete bile salts and maintain cellular integrity in response to bile stress. This study proposes a mechanism for the protection of BI_15697 against bile salt stress by MFGM, thereby providing a molecular basis for its application in incorporation of probiotics.

What are the main obstacles to turning foods healthier through probiotics incorporation? a review of functionalization of foods by probiotics and bioactive metabolites

Functional foods are gaining significant attention from people all over the world. When added to foods, probiotic bacteria can turn them healthier and confer beneficial health effects, such as improving the immune system and preventing cancer, diabetes, and cardiovascular disease. However, adding probiotics to foods is a challenging task. The processing steps often involve high temperatures, and intrinsic food factors, such as pH, water activity, dissolved oxygen, post-acidification, packaging, and cold storage temperatures, can stress the probiotic strain and impact its viability. Moreover, it is crucial to consider these factors during food product development to ensure the effectiveness of the probiotic strain. Among others, techniques such as microencapsulation and lyophilization, have been highlighted as industrial food functionalization strategies. In this review, we present and discuss alternatives that may be used to functionalize foods by incorporating probiotics and/or delivering bioactive compounds produced by probiotics. We also emphasize the main challenges in different food products and the technological characteristics influencing them. The knowledge available here may contribute to overcoming the practical obstacles to food functionalization with probiotics.

Advances in polysaccharides for probiotic delivery: Properties, methods, and applications

Probiotics are essential to improve the health of the host, whereas maintaining the viability of probiotics in harsh environments remains a challenge. Polysaccharides have non-toxicity, excellent biocompatibility, and outstanding biodegradability, which can protect probiotics by forming a physical barrier and show a promising prospect for probiotic delivery. In this review, we summarize polysaccharides commonly used for probiotic microencapsulation and introduce the microencapsulation technologies, including extrusion, emulsion, spray drying, freeze drying, and electrohydrodynamics. We discuss strategies for better protection of probiotics and introduce the applications of polysaccharides-encapsulated probiotics in functional food, oral formulation, and animal feed. Finally, we propose the challenges of polysaccharides-based delivery systems in industrial production and application. This review will help provide insight into the advances and challenges of polysaccharides in probiotic delivery.

Application of Encapsulation Strategies for Probiotics: From Individual Loading to Co-Encapsulation

Consumers are increasingly showing a preference for foods whose nutritional and therapeutic value has been enhanced. Probiotics are live microorganisms, and their existence is associated with a number of positive effects in humans, as there are many and well-documented studies related to gut microbiota balance, the regulation of the immune system, and the maintenance of the intestinal mucosal barrier. Hence, probiotics are widely preferred by consumers, causing an increase in the corresponding food sector. As a consequence of this preference, food industries and those involved in food production are strongly interested in the occurrence of probiotics in food, as they have proven beneficial effects on human health when they exist in appropriate quantities. Encapsulation technology is a promising technique that aims to preserve probiotics by integrating them with other materials in order to ensure and improve their effectiveness. Encapsulated probiotics also show increased stability and survival in various stages related to their processing, storage, and gastrointestinal transit. This review focuses on the applications of encapsulation technology in probiotics in sustainable food production, including controlled release mechanisms and encapsulation techniques.

Probiotic Encapsulation: Bead Design Improves Bacterial Performance during In Vitro Digestion

The stability and release properties of all bioactive capsules are strongly related to the composition of the wall material. This study aimed to evaluate the effect of the wall materials during the encapsulation process by ionotropic gelation on the viability of Lactobacillus fermentum K73, a lactic acid bacterium that has hypocholesterolemia probiotic potential. A response surface methodology experimental design was performed to improve bacterial survival during the synthesis process and under simulated gastrointestinal conditions by tuning the wall material composition (gelatin 25% w/v, sweet whey 8% v/v, and sodium alginate 1.5% w/v). An optimal mixture formulation determined that the optimal mixture must contain a volume ratio of 0.39/0.61 v/v sweet whey and sodium alginate, respectively, without gelatin, with a final bacterial concentration of 9.20 log10 CFU/mL. The mean particle diameter was 1.6 ± 0.2 mm, and the experimental encapsulation yield was 95 ± 3%. The INFOGEST model was used to evaluate the survival of probiotic beads in gastrointestinal tract conditions. Upon exposure to in the vitro conditions of oral, gastric, and intestinal phases, the encapsulated cells of L. fermentum decreased only by 0.32, 0.48, and 1.53 log10 CFU/mL, respectively, by employing the optimized formulation, thereby improving the survival of probiotic bacteria during both the encapsulation process and under gastrointestinal conditions compared to free cells. Beads were characterized using SEM and ATR-FTIR techniques.

Electrospinning Microencapsulation of Lactobacillus fermentum K73 Using Gelatin as the Main Component of a Food-Grade Matrix

This work aimed to establish the conditions that improve the viability of Lactobacillus fermentum K73 during and after the electrospinning process. A mixture of experimental designs were performed to select the formulation (gelatin and bacterial culture) that improves the probiotic viability after blending and under simulated gastrointestinal conditions. A Box-Behnken design was performed to improve the encapsulation yield and survival during the electrospinning process. For the Box-Behnken design, the factors were soy lecithin and bacteria culture concentration at the blend and collector distance for electrospinning. It was hypothesized that soy lecithin improved the electrospinnability, acting as a surfactant in the mixture and allowing lower voltage to be used during the process. The selected volume ratio of the gelatin (25%)/bacterial culture mixture was 0.66/0.34. The physicochemical parameters of the selected blend were in the recommended range for electrospinning. The conditions that improved the encapsulation yield and survival during electrospinning were 200 g/L of bacterial culture, 2.5% (w/v) soy lecithin, and 7 cm collector distance. The experimental encapsulation yield and survival was 80.7%, with an experimental error of 7.2%. SEM micrographs showed the formation of fibers with gelatin/bacterial culture beads. Encapsulation improved the viability of the probiotic under simulated gastrointestinal conditions compared to free cells.

Millettia speciosa Champ cellulose-based hydrogel as a novel delivery system for Lactobacillus paracasei: Its relationship to structure, encapsulation and controlled release

We report for the first time the usage of Millettia speciosa Champ cellulose (MSCC) and carboxymethylcellulose (MSCCMC) for the fabrication of 3D-network hydrogel as delivery system for probiotics. The structural features, swelling behavior and pH-responsiveness of MSCC-MSCCMC hydrogels and their encapsulation and controlled-release behavior for Lactobacillus paracasei BY2 (L. paracasei BY2) were mainly studied. Structural analyses demonstrated that MSCC-MSCCMC hydrogels with porous and network structures were successfully synthesized through the crosslinking of -OH groups between MSCC and MSCCMC molecules. An increasing concentration of MSCCMC significantly improved the pH-responsiveness and swelling ability of the MSCC-MSCCMC hydrogel toward neutral solvent. Besides, the encapsulation efficiency (50.38-88.91 %) and release (42.88-92.86 %) of L. paracasei BY2 were positively correlated with the concentration of MSCCMC. The higher the encapsulation efficiency was, the higher the release in the target intestine. However, due to the existence of bile salts, controlled-release behavior decreased the survivor rate and physiological state (degrading cholesterol) of encapsulating L. paracasei BY2. Even so, the number of viable cells encapsulated by hydrogels still reached the minimum effective concentration in the target intestine. This study provides an available reference for the practical application of hydrogels fabricated from the cellulose of the Millettia speciosa Champ plant for probiotic delivery.

Encapsulation of probiotic Lactobacillus acidophilus ATCC 4356 in alginate-galbanum (Ferula Gummosa Boiss) gum microspheres and evaluation of the survival in simulated gastrointestinal conditions in probiotic Tahini halva

One of the famous traditional confectionery products is Tahini halva. The aim of this study was the production of probiotic halva using free Lactobacillus acidophilus (FLA) and microencapsulated Lactobacillus acidophilus (MLA) with sodium alginate and galbanum gum as the second layer. The survival rate of MLA and FLA during heat stress, storage time, and simulation gastrointestinal condition in Tahini halva was assessed. The survival rates of MLA and FLA under heat stress were 50.13% and 34.6% respectively. During storage in Tahini halva, the cell viability loss was 3.25 Log CFU g-1 and 6.94 Log CFU g-1 for MLA and FLA, separately. Around 3.58 and 4.77 Log CFU g-1 bacteria were reduced after 6 h of exposure in simulated gastrointestinal conditions, for MLA and FLA respectively. These results suggest that the use of alginate and galbanum gum is a promising approach to protecting L. acidophilus against harsh environmental conditions.

Potential Application of Yeast Cell Wall Biopolymers as Probiotic Encapsulants

Biopolymers of yeast cell walls, such as β-glucan, mannoprotein, and chitin, may serve as viable encapsulants for probiotics. Due to its thermal stability, β-glucan is a suitable cryoprotectant for probiotic microorganisms during freeze-drying. Mannoprotein has been shown to increase the adhesion of probiotic microorganisms to intestinal epithelial cells. Typically, chitin is utilized in the form of its derivatives, particularly chitosan, which is derived via deacetylation. Brewery waste has shown potential as a source of β-glucan that can be optimally extracted through thermolysis and sonication to yield up to 14% β-glucan, which can then be processed with protease and spray drying to achieve utmost purity. While laminarinase and sodium deodecyle sulfate were used to isolate and extract mannoproteins and glucanase was used to purify them, hexadecyltrimethylammonium bromide precipitation was used to improve the amount of purified mannoproteins to 7.25 percent. The maximum chitin yield of 2.4% was attained by continuing the acid-alkali reaction procedure, which was then followed by dialysis and lyophilization. Separation and purification of yeast cell wall biopolymers via diethylaminoethyl (DEAE) anion exchange chromatography can be used to increase the purity of β-glucan, whose purity in turn can also be increased using concanavalin-A chromatography based on the glucan/mannan ratio. In the meantime, mannoproteins can be purified via affinity chromatography that can be combined with zymolase treatment. Then, dialysis can be continued to obtain chitin with high purity. β-glucans, mannoproteins, and chitosan-derived yeast cell walls have been shown to promote the survival of probiotic microorganisms in the digestive tract. In addition, the prebiotic activity of β-glucans and mannoproteins can combine with microorganisms to form synbiotics.

Enhanced viability of probiotics encapsulated within synthetic/natural biopolymers by the addition of gum arabic via electrohydrodynamic processing

To enhance the probiotics' viability, novel vehicles consisting of synthetic/natural biopolymers, i.e., polyvinyl alcohol (PVOH), polyvinylpyrrolidone, whey protein concentrate and maltodextrin, encapsulated with L. plantarum KLDS 1.0328 and gum arabic (GA) as a prebiotic were fabricated by electrohydrodynamic techniques. Inclusion of cells into composites caused an increase in conductivity and viscosity. Morphological analysis showed that cells were distributed along the electrospun nanofibres or distributed randomly in the electrosprayed microcapsules. Both intramolecular and intermolecular hydrogen bond interactions exist between biopolymers and cells. Thermal analysis revealed that the degradation temperatures (>300 °C) of various encapsulation systems have potential applications in heat-treatment foods. Additionally, cells especially immobilized in PVOH/GA electrospun nanofibres showed the highest viability compared with free cells after exposure to simulated gastrointestinal stress. Furthermore, cells retained their antimicrobial ability after rehydration of the composite matrices. Therefore, electrohydrodynamic techniques have great potential in encapsulating probiotics.

Electrospinning and Electrospraying: Emerging Techniques for Probiotic Stabilization and Application

Probiotics are beneficial for human health. However, they are vulnerable to adverse effects during processing, storage, and passage through the gastrointestinal tract, thus reducing their viability. The exploration of strategies for probiotic stabilization is essential for application and function. Electrospinning and electrospraying, two electrohydrodynamic techniques with simple, mild, and versatile characteristics, have recently attracted increased interest for encapsulating and immobilizing probiotics to improve their survivability under harsh conditions and promoting high-viability delivery in the gastrointestinal tract. This review begins with a more detailed classification of electrospinning and electrospraying, especially dry electrospraying and wet electrospraying. The feasibility of electrospinning and electrospraying in the construction of probiotic carriers, as well as the efficacy of various formulations on the stabilization and colonic delivery of probiotics, are then discussed. Meanwhile, the current application of electrospun and electrosprayed probiotic formulations is introduced. Finally, the existing limitations and future opportunities for electrohydrodynamic techniques in probiotic stabilization are proposed and analyzed. This work comprehensively explains how electrospinning and electrospraying are used to stabilize probiotics, which may aid in their development in probiotic therapy and nutrition.

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.

A systematic review on selection characterization and implementation of probiotics in human health

Probiotics are live bacteria found in food that assist the body's defence mechanisms against pathogens by reconciling the gut microbiota. Probiotics are believed to aid with gut health, the immune system, and brain function, among other factors. They've furthermore been shown to help with constipation, high blood pressure, and skin issues. The global probiotics market has been incrementally growing in recent years, as consumers' demand for healthy diets and wellness has continued to increase. This has prompted the food industry to develop new probiotic-containing food products, as well as researchers to explore their specific characteristics and impacts on human health. Although most probiotics are fastidious microorganisms that are nutritionally demanding and sensitive to environmental conditions, they become less viable as they are processed and stored. In this review we studied the current literature on the fundamental idea of probiotic bacteria, their medical benefits, and their selection, characterization, and implementations.

Graphical Abstract

Development of engineered probiotics with tailored functional properties and their application in food science

The potential health benefits of probiotics may not be cognized because of the substantial curtailment in their viability during food storage and passage through the gastrointestinal system. Intestinal flora composition, and resistance against pathogens are among the health benefits associated with probiotic consumption. In the gastric environment, pH 2.0, probiotics dramatically lose their viability during the transit through the gastrointestinal system. The challenge remains to maintain cell viability until it reaches the large intestine. In extreme conditions, such as a decrease in pH or an increase in temperature, encapsulation technology can enhance the viability of probiotics. Probiotic bacterial strains can be encapsulated in a variety of ways. The methods are broadly systematized into two categories, liquid and solid delivery systems. This review emphasizes the technology used in the research and commercial sectors to encapsulate probiotic cells while keeping them alive and the food matrix used to deliver these cells to consumers.

Graphical abstract

Encapsulating biocontrol bacteria with starch as a safe and edible biopolymer to alleviate plant diseases: A review

Healthy foods with few artificial additives are in high demand among consumers. Preserving conventional pesticides, frequently used as chemicals to control phytopathogens, is challenging. Therefore, we proposed an innovative approach to protect agricultural products in this review. Biocontrol bacteria are safe alternatives with low stability and low efficiency in the free-form formulation. The encapsulation technique for covering active compounds (e.g., antimicrobials) represents a more efficient protection technology because encapsulation causes the controlled release of bioactive materials and reduces the application doses. Of the biopolymers able to form a capsule, starch exhibits several advantages, such as its ready availability, cost-effectively, edible, colorless, and tasteless. Nevertheless, the poor mechanical properties of starch can be improved with other edible biopolymers. In addition, applying formulations incorporated with more than one antimicrobial material offers synergistic effects. This review presented the starch-based capsules used to enclose antimicrobial agents as effective tools against phytopathogens.