Lactic acid bacteria are important probiotics widely found in nature and recognized for their health-promoting roles in fermented foods and their probiotic functions in the human gut. In recent years, postbiotics-defined as inanimate metabolites or components of probiotics-have gained increasing attention. Extracellular vesicles derived from lactic acid bacteria (LAB-EVs) represent a unique category of postbiotics with notable bioactivity and stability, holding broad potential for food applications. This review systematically examines the biogenesis, molecular composition, and dual applications of LAB-EVs in food and health. In food systems, LAB-EVs can serve as natural preservatives by inhibiting pathogens and biofilms, as fermentation modulators by mediating microbial interactions, and as efficient nanocarriers for delivering flavors and nutrients. Furthermore, LAB-EVs contribute to gut health by enhancing barrier function, modulating immune balance, and maintaining microbiota homeostasis. To bridge the gap between research and industrial application, this review highlights key strategies for enhancing EV yield, optimizing purification protocols, and enabling functional engineering. In summary, LAB-EVs constitute an advanced bioactive platform with significant potential for developing next-generation functional foods and promoting the innovative application of postbiotics in the food industry.

Inflammatory dysregulation of bone metabolism underlies a range of skeletal pathologies, including osteoporosis, osteoarthritis, and periprosthetic loosening. Although probiotic metabolites demonstrate multifaceted nutritional benefits, the development of Bifidobacterium-derived extracellular polysaccharides remains limited. Consequently, we extracted extracellular polysaccharides from Bifidobacterium animalis RH (designated EPS, 21.3 kDa) and explored their therapeutic potential and mechanisms in inflammatory bone disorders. For in vitro models, we employed lipopolysaccharide (LPS)-stimulated MC3T3-E1 osteoblasts and RANKL-induced RAW 264.7 osteoclast precursors treated with increasing EPS concentrations. EPS restored LPS-impaired osteoblast function, enhancing proliferation, differentiation, mineralization, and collagen synthesis. This restoration was evidenced by increased ALP activity, calcium nodule formation, collagen expression, and suppressed pro-inflammatory cytokine secretion (IL-6, IL-1β, IL-17a/f). EPS mediated this osteogenic recovery by inhibiting the TLR4/NF-κB pathway and activating RUNX2 transcription. Concurrently, EPS attenuated osteoclastogenesis by reducing inflammatory cytokines (IL-6, IL-1β, TNF-α), inhibiting ROS generation, downregulating RANK expression, and disrupting the MITF/PU.1/NFATc1 transcriptional network governing key osteoclast-specific genes (e.g., TRAP, CTSK). This study systematically elucidated the dual regulatory mechanisms of EPS in inflammatory bone disorders, highlighting their promising therapeutic potential for skeletal pathologies and providing a foundation for developing in vivo models and dietary biotherapeutics.

Plant-derived extracellular vesicles (PDEVs) are nanoscale lipid bilayer particles secreted by plant cells, carrying various bioactive molecules and exhibiting good biocompatibility and safety. They have emerged as promising candidates for functional food compounds and active delivery carriers. This review summarizes recent advances in the extraction, purification, characterization, and engineering of PDEVs, highlighting their multiple application potentials in the food field, especially in functional enhancement, bioactive delivery, and high-value utilization of agricultural by-products. Despite their advantages, large-scale application remains limited by technical challenges, necessitating further systematic research.

Due to the limitations of macro sequencing, high-throughput sequencing (HTS) cannot reflect the microbial community structure in sterilized food. This study combines HTS with cultivable cell counting to confirm the presence of bacterial contamination in both commercial factory-produced liquid milk, demonstrating that most contamination. We further traced the main source of bacterial contamination to the filling process. Bacillus dominates throughout the filling line, after enrichment, cultivable Bacillus counts in filling head samples reach 3.81 CFU/cm², highlighting their persistence. Liquid milk’s nutrient-rich environment supports Bacillus growth, while rough stainless steel surfaces in filling equipment promote biofilm formation. Confocal microscopy revealed multi-layered biofilms with extracellular matrices, making them resistant to Cleaning-in-Place (CIP) processes. After CIP, Bacillus counts remained at 4.69 CFU/mL, suggesting survival and potential quality risks. This study highlights Bacillus biofilm persistence in filling lines and offers insights for improving CIP protocols to maintain a sterile filling environment for liquid milk.

Alcohol-associated liver disease (ALD) has limited therapeutic options due to its complex pathogenesis. This study demonstrates the ALD-protective effects of extracellular nanoparticles derived from Bifidobacterium bifidum (BNPs), focusing on the concept of gut microbiota-derived nanoparticles (GNPs) in disease pathogenesis. When isolated BNPs were administered in an ALD mouse model, they upregulated Vsig4 receptor expression in liver macrophages, improving phagocytic clearance of harmful GNPs that contained bacterial DNA. GNPs activated liver inflammation via the cGAS-STING pathway, exacerbating ALD and liver fibrosis in Vsig4-deficient mice. BNP treatment suppressed the inflammatory cascade, modulated macrophage polarization, and reduced hepatic steatosis and liver injury, while also restoring the balance of the gut microbiota and enhancing intestinal barrier function. These findings reveal the role of GNPs in ALD pathogenesis and present targeted microbial nanoparticle postbiotics as potential therapeutics for treatment of alcohol-associated and other liver diseases.

Exopolysaccharides (EPS) produced by lactic acid bacteria have gained increasing attention as clean-label stabilizers for fermented dairy products. However, limited production efficiency and insufficient understanding of structure-function relationships restrict their wider application. In this study, an EPS (GS-EPS) from Lactobacillus gasseri was produced under optimized fermentation conditions using single-factor experiments combined with response surface methodology, achieving a yield of 4.49 g/L. Structural characterization revealed GS-EPS to be a heteropolysaccharide with a relatively low molecular weight (14.1 kD) and mixed glycosidic linkages (alpha- and beta-glycosidic linkages). Incorporation of GS-EPS into fermented milk markedly improved the physicochemical and textural properties, including increased firmness, viscosity, and water-holding capacity, alongside reduced syneresis and delayed post-acidification during storage, with 0.4 g/L identified as the optimal concentration. Spectroscopic analyses (Raman and FT-IR) revealed that GS-EPS supplementation was associated with detectable changes in protein structural features in fermented milk. These structural signatures were consistent with the observed improvements in macroscopic quality attributes, suggesting that GS-EPS contributes to the modulation of gel structure formation. Overall, this study demonstrates that GS-EPS represents an effective clean-label stabilizer capable of improving the quality and storage stability of fermented milk, providing practical insights for the development of EPS-based functional dairy products.

Meat processing wastewater presents a significant environmental challenge, largely due to inefficient enzymatic degradation of chondroitin sulfate (CS). This study introduces a novel chondroitinase (Ps_Chase) from Pseudarthrobacter sp. PL-410, exhibiting a 50 % higher enzymatic activity (850.7 U/mg) than commercial Chase ABC. Ps_Chase displays exceptional thermostability, maintaining over 80 % activity after 180 min at 37 degrees C and demonstrating half-lives of 420 min (CS-A) and 480 min (CS-C). It shows high specificity for CS-C, with a low Km (0.0425 mg/mL) and high Vmax (0.171 mu mol/min.mL), and achieves a 59.36 % yield of 1-3 kDa oligosaccharides, increasing bioavailability by 140 %. Compared to other enzymes, Ps_Chase reduced chitosan molecular weight by 48.8 % and increased absorbance at 232 nm by 1.5-2-fold, demonstrating superior depolymerization efficiency. Structural analysis highlights several conserved catalytic residues (H271, R334, Y280, E445), with mutagenesis confirming their essential roles in catalysis. Molecular simulations revealed stable substrate binding, enhanced compactness, and the highest hydrogen bond count (9.68) for CS-C. QM/MM simulations identified a two-step proton transfer mechanism, with H271 and R334 catalyzing cleavage via beta-elimination, exhibiting a rate-limiting energy barrier of 26.11 kcal/mol, which was significantly lower than for CS-B (37.89 kcal/mol). Y280 was found to stabilize the carbanion intermediate through hydrogen bonding. In volume-dependent experiments (0.5-3 L), Ps_Chase consistently reduced BOD and COD levels by up to 42 %. This outcome indicates the effective depolymerization of CS-rich substrates under controlled conditions. These results demonstrate Ps_Chase's catalytic efficiency, substrate selectivity, and mechanistic features, providing a basis for future exploration of environmentally relevant applications in chondroitin sulfate valorization.

Probiotic extracellular vesicles (EVs) have garnered attention as a natural nano-delivery system for food applications. However, studies on using EVs as a food preservative-carrying system are limited. Lactococcus lactis L-WY410 is a promising bacteriocin-producing probiotic strain with the po tential to secrete EVs. This study aims to investigate the potential of L. lactis L-WY410 extracellular vesicles (L-EVs) as a delivery system for preservatives. Notably, nisin Z, class I bacteriocin, was observed within the L-EVs by LC-MS/MS and ELISA analysis. Antibacterial assays demonstrated the antibacterial activity of L-EVs was significantly higher than that of free nisin Z in inhibiting the growth of foodborne pathogens, such as Staphylococcus aureus, Listeria monocytogenes. More importantly, L-EVs exhibited superior activity retention under various environmental conditions (e.g., different pH, temperature, and protease). This study shows the potential of probiotics EVs as a natural nano-delivery system for food preservative application.

Bacteriocins, naturally derived antimicrobial peptides, are considered promising alternatives to traditional preservatives and antibiotics, particularly in food and medical applications. Despite extensive research on various bacteriocins, cyclic varieties remain understudied. This study introduces Gassericin GA-3.1, a novel cyclic bacteriocin produced by Lactobacillus gasseri LG145. We employed a multi-step purification process, including salt precipitation, ion-exchange chromatography, gel filtration chromatography, and ultimately highperformance liquid chromatography (HPLC), achieving a specific activity of 4660.89 AU/mg for the purified Gassericin GA-3.1. Mass spectrometry revealed a molecular mass of 5613.842 Da. Genome analysis confirmed Gassericin GA-3.1 as a novel class IIc bacteriocin with a unique amino acid sequence. Secondary structure prediction suggested the presence of three alpha-helices, two beta-pleated strands, and a random coil. Physicochemical characterization demonstrated GassericinGA-3.1's thermal stability, resistance to pH extremes, surfactants, and broad-spectrum antibacterial potency. Notably, Gassericin GA-3.1 effectively inhibit Listeria monocytogenes through mechanism involving surface perforation, membrane potential disruption, and downregulation of virulence, biofilm formation, and motility genes. Overall, our finding position Gassericin GA-3.1 as a potential candidate for antimicrobial applications in the food and health industries.

This study aimed to investigate the effect of using an optimized complex sodium salt substitute formulation, comprising potassium lactate (17.64%), potassium chloride (14.61%), magnesium chloride (34.36%), and sodium chloride (33.39%), on the quality of Oncorhynchus masou caviar at different storage temperatures and to compare it with the traditional sodium chloride curing method. Caviar samples were stored at 20, 27, and 34 u00B0C, respectively, and the effect of the new formulation on the quality characteristics of the caviar was systematically evaluated through the determination of microbiological indicators, pH, water activity, total volatile basic nitrogen content and other physicochemical indicators. In addition, the shelf life of the samples at 0 and 4 u00B0C was predicted using the accelerated shelf life test model. The results showed that using sodium salt substitute formulation could effectively inhibit microbial growth, slow down the spoilage process of the product, and significantly extend the shelf-life of caviar, which is a significant advantage over the traditional sodium chloride curing method. This study provides theoretical support and practical guidance for the improvement of caviar processing technology and salt reduction in the food industry.

Background Probiotics have garnered significant attention for their potential to enhance human health. However, the challenge lies in their limited survival rates in harsh gastrointestinal environments, which hinders their therapeutic efficacy. Biofilm-state probiotics, characterized by enhanced stress resistance and colonization capabilities, offer a promising solution. Scope and approach This review comprehensively examines the biofilm formation process, influencing factors, and the advantages of biofilm-state probiotics. It delves into the intramembrane interactions and highlights the current understanding of their health benefits and innovative application methods. Key findings and conclusions Biofilm-state probiotics demonstrate superior persistence within human tissues, thereby sustaining their health-promoting functions. Employing molecular biology techniques and advanced biotechnological approaches can facilitate the development of novel, high-performance biofilm-state probiotics, addressing the colonization challenges faced by conventional probiotics.

This study systematically evaluated the digestive stability and prebiotic potential of extracellular polysaccharides (EPS) derived from Bifidobacterium animalis RH using in vitro digestion and fecal fermentation models. Digestion (INFOGEST 2.0) revealed that EPS maintained structural integrity: total carbohydrates remained stable (59.38-60.12 %), while reducing sugars increased moderately (0.125-0.207 mg/mL), indicating partial dissociation. Structural characterization (SEM, GPC, IC, FT-IR) confirmed preserved molecular weight, monosaccharide composition, and functional groups, alongside retained α-glucosidase and enhanced α-amylase inhibition. Fermentation with human fecal microbiota revealed digested EPS selectively enriched beneficial genera (Bacteroides, Bifidobacterium, Collinsella, Parabacteroides, and Faecalibacterium) while suppressing pathogens (Escherichia-Shigella, Fusobacterium, Lachnospiraceae_UCG-010, Phascolarctobacterium, and Dialister). This shift correlated with decreased pH and sustained short-chain fatty acid (SCFA) production (37.63 mmol/L total SCFAs at 24 h), particularly butyrate linked to Faecalibacterium. These findings highlight EPS as a digestion-resistant polysaccharide with significant prebiotic potential as a gut-targeted functional ingredient for supporting intestinal health.

Sea buckthorn (Hippophae rhamnoides L.) is a natural homologous substance of medicine and food. Polysaccharide, as one of its primary active components, has very superior biological activity and can be used as a dietary supplement for functional foods, with good commercial prospects. Although initial progress has been made in the study of sea buckthorn polysaccharides, related studies have been fragmented and lacked systematic and generalization. This manuscript presents a critical analysis and systematic summary of the extraction and purification methods, structural characterization and physicochemical properties, biological activity and potential mechanisms, and structure-activity relationships of sea buckthorn polysaccharides. Accumulating evidence has indicated that sea buckthorn polysaccharides, which were widely prepared by water extraction and column chromatography purifications, exhibited exhibit superior biological activities in vitro and in vivo, including antioxidant, immunomodulatory, anti-inflammatory, hepatorenal protective, antibacterial, antiviral, and prebiotic activities. After analysis, it was concluded that there is a correlation between the relevant activities of sea buckthorn polysaccharides and that the structure of sea buckthorn polysaccharides has a great influence on their biological activity. We reviewed the challenges and limitations of sea buckthorn polysaccharides, summarized the critical aspects, and provided suggestions for potential breakthroughs in the research and application of sea buckthorn polysaccharide.

Weizmannia coagulans (formerly Bacillus coagulans) is a spore-forming and lactic acid-producing bacterium. It has recently attracted much attention from researchers and food manufacturers due to its probiotic functions and stability in processing and storage. W. coagulans is capable of improving gut health through the regulation of gut microbiota, modulation of immunity, and improving digestibility and metabolism. Spores, germinated cells and metabolites of W. coagulans modulate the gut micro-environment and further affect other organs. W. coagulans is an environment-friendly probiotic since it can contribute to the host by reconstructing the balance of gut microbiota and only temporarily resides in the intestine after administration. W. coagulans has been generally recognized as safe (GRAS) by the US Food and Drug Administration (FDA), thus it is an ideal probiotic for improving gut health. The merit of its stability in processing and storage provides W. coagulans spores many possibilities for its use in various types of functional foods. This review presents an overview of the characteristics of W. coagulans that make it an ideal probiotic candidate and highlights the proposed health benefits with scientific evidence conferred by the administration of W. coagulans.

In recent years, the growing concern over human health risks associated with chemical preservatives in food has sparked increased interest in utilizing natural biopreservatives derived from probiotics. Bacteriocins, which are antibacterial peptides that have been deemed safe for human consumption and have been applied to food preservation. Several studies have emphasized that nanoparticles derived from edible plants can modulate microbes' metabolic processes. In this study, we discovered that Lactobacillus plantarum LPL-1 can produce extracellular nanoparticles (LPL-NPs) containing a specific class IIa bacteriocin known as plantaricin LPL-1. LPL-NPs effectively suppressed the growth of Listeria monocytogenes 54002 by gradually disrupting their cell membranes. Intriguingly, we have also demonstrated that the ginger derived exosome-like NPs (GELNPs) enhance the antibacterial activity of LPL-NPs by enriching plantaricin LPL-1 within them through activation of a quorum sensing system component. Furthermore, GELNPs-treated LPL-NPs (GLPL-NPs) can effectively extend the storage period of sturgeon at 4 degrees C by mitigating pathogenic bacterial growth, preserving sensory quality, and reducing the levels of total volatile basic nitrogen (TVB-N), K value, trichloroacetic acid (TCA)-soluble peptides, and thiobarbituric acid reactive substances (TBARS). This study provides insight into a strategy for application of LPL-NPs as a natural biopreservative for food preservation.

Collagen, recognized as a fundamental protein present in biological tissues and structures, plays a crucial role in maintaining organ structure and tissue integrity. Microbial collagenases are specific for the degradation of collagen. The specific three-stranded helix region of natural collagen can be identified and hydrolyzed by microbial collagenases under physiological conditions, producing collagen peptides with high physiological activity. This article describes microbial collagenases, providing an introduction to the structure, physiological characteristics, factors affecting enzyme activity, and hydrolysis mechanisms of various classes of these enzymes. Microbial collagenase is the most widely used class of collagenase and plays an important role in all aspects of human life, and various applications of microbial collagenases in food industry, healthcare and environmental protection will be addressed in this review. In addition to its beneficial functions, microbial collagenase can exist as a virulence factor for pathogenic bacteria, and enhanced research on its structure and mechanism of action will help us to investigate more effective inhibitors as well as therapeutic agents and tools for the treatment of the corresponding diseases. Finally, this review critically analyses existing challenges and outlines prospects for future advancements in the field.

Oral probiotics meet challenges during processing, storage, and gastrointestinal harsh conditions. Polysaccharide-based hydrogels delivery system is promising in probiotic protection, but its semi-solid and weak strength, and often requires additional cross-links to solidify its structure. Herein a ferric ion co-crosslinked microgel of Mesona chinensis polysaccharides and mechanically strengthened by phenolic-metal frameworks of naturally bound brown bioactives is designed. These microgels has an intact structure in acidic condition and ruptured only at pH neutral conditions which can responsively release highly viable probiotics with high mucoadhesion and colonization. Brown bioactives are naturally bound to polysaccharides (MCPC) by hydrophobic interactions and hydrogen bonding, and they exhibited outstanding anti-inflammatory and antioxidant properties. Moreover, these brown bioactives are the precise prebiotics which can specifically improve the abundance of Akkermansia genus in gut in vivo. Then, the probiotics Akkermansia muciniphila (AKK) are loaded into brown bioactives frameworks strengthened microgels. There is a more synergistic healthy benefit between MCPC components and loaded AKK compared with free and pasteurized AKK. MCPC microgels can deliver high viable AKK specifically to gut consequently modulating the microbiota balance, and protecting the intestinal barriers. MCPC microgels also delivered the antioxidant brown bioactives specifically into liver to alleviate the hepatic oxidative stress and inflammation.

Heyndrickxia coagulans (formerly Bacillus coagulans) has been increasingly utilized as an immunomodulatory probiotics. Oral administration of H. coagulans HOM5301 significantly boosted both innate and adaptive immunity in mice, particularly by increasing the phagocytic capacity of monocytes/macrophages. Lipoteichoic acid (LTA), a major microbe-associated molecular pattern (MAMP) in Gram-positive bacteria, exhibits differential immunomodulatory effects due to its structural heterogeneity. We extracted, purified, and characterized LTA from H. coagulans HOM5301. The results showed that HOM5301 LTA consists of a glycerophosphate backbone. Its molecular weight is in the range of 10–16 kDa. HOM5301 LTA induced greater productions of nitric oxide, TNFα, and IL-6 in RAW 264.7 macrophages compared to Staphylococcus aureus LTA. Comparative transcriptome and proteome analyses identified the differentially expressed genes and proteins triggered by HOM5301 LTA. KEGG analyses revealed that HOM5301 LTA transcriptionally and translationally activated macrophages through two immune-related pathways: cytokine–cytokine receptor interaction and phagosome formation. Protein–protein interaction network analysis indicated that the pro-inflammatory response elicited by HOM5301 LTA was TLR2-dependent, possibly requiring the coreceptor CD14, and is mediated via the MAPK and NF-kappaB pathways. Our results demonstrate that LTA is an important MAMP of H. coagulans HOM5301 that boosts immune responses, suggesting that HOM5301 LTA may be a promising immunoadjuvant.

Metallothionein is a cysteine-rich protein with a high metal content that is widely found in nature. In addition to heavy metal detoxification, metallothionein is well known as a potent antioxidant. The high sulfhydryl content of metallothionein confers excellent antioxidant activity, enabling it to effectively scavenge free radicals and mitigate oxidative stress damage. In addition, metallothionein can play a neuroprotective role by alleviating oxidative damage in nerve cells, have an anticancer effect by enhancing the ability of normal cells to resist unfavorable conditions through its antioxidant function, and reduce inflammation by scavenging reactive oxygen species. Due to its diverse biological functions, metallothionein has a broad potential for application in alleviating environmental heavy metal pollution, predicting and diagnosing diseases, and developing skin care products and health foods. This review summarizes the recent advances in the classification, structure, biological functions, and applications of metallothionein, focusing on its powerful antioxidant effects and related functions.

Class IIa bacteriocins produced in lactic acid bacteria are short cationic peptides with antimicrobial activity. In the search for new biopreservation agents, class IIa bacteriocins are considered to be the best potential candidates, not only due to their large abundance but also because of their high biological activity and excellent thermal stability. However, regulated by the biosynthetic regulatory system, the natural class IIa bacteriocin yield is low, and the extraction process is complicated. The biotechnological production of class IIa bacteriocins in various cell factories has been attempted to improve this situation. In this review, we focus on the application of biotechnological routes for class IIa bacteriocin production. The drawbacks and improvements in the production of class IIa bacteriocins in various cell factories are discussed. Furthermore, we present the main challenge of class IIa bacteriocins, focusing on increasing their production by constructing suitable cell factories. Recombinant bacteriocins have made considerable progress from inclusion body formation, dissolved form and low antibacterial activity to yield recovery. The development of prospective cell factories for the biotechnological production of bacteriocins is still required, which may facilitate the application of bacteriocins in the food industry.