Exopolysaccharides of Lactic Acid Bacteria: Production, Purification and Health Benefits towards Functional Food

Antioxidant potential of exopolysaccharides from lactic acid bacteria: A comprehensive review

Exopolysaccharides (EPSs) from lactic acid bacteria (LAB) have multifunctional capabilities owing to their diverse structural conformations, monosaccharide compositions, functional groups, and molecular weights. A review paper on EPS production and antioxidant potential of different LAB genera has not been thoroughly reviewed. Therefore, the current review provides comprehensive information on the biosynthesis of EPSs, including the isolation source, type, characterization techniques, and application, with a primary focus on their antioxidant potential. According to this review, 17 species of Lactobacillus, five species of Bifidobacterium, four species of Leuconostoc, three species of Weissella, Enterococcus, and Lactococcus, two species of Pediococcus, and one Streptococcus species have been documented to exhibit antioxidant activity. Of the 111 studies comprehensively reviewed, 98 evaluated the radical scavenging activity of EPSs through chemical-based assays, whereas the remaining studies documented the antioxidant activity using cell and animal models. Studies have shown that different LAB genera have a unique capacity to produce homo- (HoPs) and heteropolysaccharides (HePs), with varied carbohydrate compositions, linkages, and molecular weights. Leuconostoc, Weissella, and Pediococcus were the main HoPs producers, whereas the remaining genera were the main HePs producers. Recent trends in EPSs production and blending to improve their properties have also been discussed.

Optimization of exopolysaccharide production from the novel Enterococcus species, using statistical design of experiment

The Exopolysaccharide (EPS) producing novel strains of Enterococcus previously isolated from the vaginal source of pregnant women were selected based on ropy structure formation. The two selected strains, E.villorum SB-2 and E.rivorum S22-3, were found to be producing 2.87 g/l and 3.14 g/l EPS, respectively, in the minimal media (M17 media) after 24-hour fermentation under anaerobic condition. Both the strains have probiotic properties and have the potential to be used for industrial applications. The production media and fermentation conditions were optimized to enhance the EPS production using the one-factor method, Placket-Burman factorial designing and Central composite design (CCD) of Response surface methodology (RSM). The most relevant factors affecting the EPS yield were sucrose, yeast extract and pH for E.villorum SB2 and sucrose, yeast extract and magnesium sulfate for the E.rivorum S22-3 as determined by Placket-Burman design, whose concentrations were further optimized using CCD. The optimized fermentation conditions gave the total EPS of 9.76 g/l (4 times the initial production) from E.villorum SB-2 and 7.74 g/l (2.5 times the initial production) from E.rivorum S22-3, respectively, after 36-hour incubation at 37 °C. These optimization studies might be helpful during scale-up process for the industrial scale production of these exopolysaccharide.

Advances in Microbial Exopolysaccharides: Present and Future Applications

Microbial exopolysaccharides (EPSs) are receiving growing interest today, owing to their diversity in chemical structure and source, multiple functions, and immense potential applications in many food and non-food industries. Their health-promoting benefits for humans deserve particular attention because of their various biological activities and physiological functions. The aim of this paper is to provide a comprehensive review of microbial EPSs, covering (1) their chemical and biochemical diversity, including composition, biosynthesis, and bacterial sources belonging mainly to lactic acid bacteria (LAB) or probiotics; (2) their technological and analytical aspects, especially their production mode and characterization; (3) their biological and physiological aspects based on their activities and functions; and (4) their current and future uses in medical and pharmaceutical fields, particularly for their prebiotic, anticancer, and immunobiotic properties, as well as their applications in other industrial and agricultural sectors.

Characterization of Lactic Acid Bacterium Exopolysaccharide, Biological, and Nutritional Evaluation of Probiotic Formulated Fermented Coconut Beverage

Exopolysaccharides (EPSs), produced by lactic acid bacteria (LAB), play a crucial role in enhancing the texture and stability of yoghurt by forming a protective matrix that helps to maintain its rheological and sensory characteristics. The search for a dairy alternative for the lactose-intolerant populace is a necessity, and the use of probiotic LAB and their EPS to formulate fermented coconut beverage (FFCB) will be of added advantage. The production and characterization of EPS from a LAB strain isolated from yoghurt, its probiotic and antioxidant potential, and its application in the production of probiotic FFCB were investigated. The EPS produced by the isolate was characterized using a scanning electron microscope (SEM), high-performance liquid chromatography, Fourier transform infrared (FT-IR) spectroscopy, and energy-dispersive X-ray. The antioxidant potential of the EPS was determined. The isolate probiotic potential, such as tolerance to low pH, bile salts, gastric pH, autoaggregation, coaggregation, antimicrobial potential, and antibacterial activity, was evaluated, and the isolate was identified using 16S rRNA. The LAB strain and the EPS were used for the formulation of probiotic FFCB, and the proximate mineral composition of the enriched yoghurt was determined. Isolate W3 produced 6204.50 mg/L EPS. The EPS produced by the LAB was spherical with a coarse surface. Hydroxyl, carboxyl, and α-pyranose were the major functional groups present in the EPS. Eight monosaccharides were present in glucose, which has the highest molar ratio. The EDX spectra ascertain the presence of carbon, oxygen (carbohydrate), and other elements. The purified EPS exhibited antioxidant activity in a dose-dependent manner. DPPH, FRAP, TAC, and TPC of the EPS ranged from 42.36% to 75.88%, 2.48 to 5.31 μg/mL, 1.66 to 3.57 μg/mL, and 1.42 to 2.03 μg/mL, respectively. The LAB strain exhibited moderate tolerance to low pH, bile salts, gastric juice, good autoaggregation (13.33%), coaggregation (0%-59.09%) with E. coli, and varied sensitivity to different antibiotics used. The isolate is hemolysis, deoxyribonuclease (DNase), and lecithinase negative, possesses characteristics of probiotics, and could have the ability to confer health benefits. The LAB strain has a 100.0% pairwise identity to Pediococcus acidilactici. The FFCB has pH, lactic acid, specific gravity, total soluble solids (TSSs), and vitamin C content ranging from 5.81 to 6.8, 10.8 to 55.8 mg/L, 0.910 to 1.394 kg/m3, 0.136 to 0.196 °Bx, and 0.26% to 0.66%. The formulated beverage fermented with a commercial starter had the highest lactic acid at Day 7 of storage. The FFCB sample with the commercial starter and the probiotic strain had the highest ash and crude fiber content (1.3%, 0.68%). The FFCB fortified with EPS showed the highest protein content (4.6%). The formulated yogurt samples fortified with the highest concentration of EPS had the highest calcium content after 7 days of storage (162.31 ± 0.01a). In conclusion, EPS produced by Pediococcus acidilactici was a heteropolymeric EPS with good antioxidant activity, and the LAB strain exhibited a good starter for producing FFCB enriched with EPS. The FFCB has good nutritional characteristics and could serve as a functional and natural nutraceutical food for the lactose intolerance population.

Functional characterization and biotechnological applications of exopolysaccharides produced by newly isolated Enterococcus hirae MLG3-25-1

This study investigated the potential applications of Enterococcus hirae MLG3-25-1 exopolysaccharides (EPS), with a focus on their isolation, identification, production, and functional characteristics. After the bacterial strain was cultured in De Man-Rogosa-Sharpe (MRS) medium containing 1% glucose at 37 °C, the EPS was refined, and the highest yield of 0.85 mg/mL was achieved at the 24-h incubation period. Enterococcus hirae MLG3-25-1 was found to be able to produce EPS. The study explored the microstructure of the EPS, which resembles polysaccharide sheets with smooth surfaces, through scanning electron microscope (SEM) analysis. Through Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) analysis, the chemical composition, aligning with glycosidic bond characteristics, has been deciphered. Furthermore, the antimicrobial and antibiofilm activities against pathogenic bacteria, particularly Bacillus sp., demonstrated potential applications in combating antibiotic resistance. The EPS exhibited notable antioxidant activity (89.36% DPPH scavenging), along with high water-holding capacity (575%), emulsifying activity, and flocculation activity, suggesting its potential as a stabilizing agent in the food industry. Overall, this study provides a comprehensive characterization of Enterococcus hirae MLG3-25-1 EPS, emphasizing its diverse applications in antimicrobial, antioxidant, and food-related industries. These findings lay the groundwork for further exploration and utilization of this EPS in various sectors.

Exopolysaccharide from Leuconostoc mesenteroides XR1: Yield optimization, partial characterization and properties

The production conditions of exopolysaccharide (EPS) from Leuconostoc mesenteroides XR1 were optimized by response surface methodology (RSM). Maximum EPS yield was 56.59 ± 0.51 g/L under fermentation conditions with 2.6 g/L ammonium citrate, initial pH 6.5 and temperature 23 °C, which was 6.21-fold greater than the EPS yield before optimization. Characterization of the chain conformation using Congo red test and circular dichroism (CD) showed that EPS exhibited a random coil structure in aqueous solution. The CD results revealed that the EPS concentration altered its hydrogen-bond interactions and chirality, but did not change its chain conformation. The average polydispersity index (PDI) of the EPS solution was only 27.16 %, indicating that it was uniformly distributed in the aqueous solution with high stability. The degradation temperature of EPS was 253.11 °C, indicating high thermal stability. EPS possessed the ability to scavenge activities of free radicals and was protective against oxidative stress-induced plasmid DNA damage. In addition, stable hydrogels could be formed at EPS concentrations above 5 % (w/v). These results collectively showed that EPS can be used commercially as an antioxidant and drug delivery carrier.

Preparation of Novel Marine Enterococcus faecium MSD8 Exopolysaccharide Ointment and In Vivo Evaluation of Its Impact on Cutaneous Wound Healing in Male Albino Rats

The current study describes the isolation of exopolysaccharide (EPS) producing lactic acid bacteria (LAB) from marine samples and testing different sugar additives with different proportions for enhanced EPS yield. The isolate MSD8 showed the most potential, yielding 200 mg/L of EPS after being cultivated at 37 °C for 48 h on de Man Rogosa and Sharpe medium (MRS) supplemented with 3% sucrose. The marine isolate MSD8 was identified as Enterococcus faecium with 99.58% probability using 16S rRNA gene sequencing. The obtained sequence was deposited in GenBank and assigned the accession number MW924065. The feature of MSD8-EPS was characterized by estimating the total carbohydrate content by UV-vis to be ~ 71%. The FTIR analysis further indicated the presence of characteristic bands of polysaccharide. The cytotoxicity of the produced MSD8-EPS was assessed using human skin fibroblasts (HSF). The IC50 was determined to be > 100 μg/mL, which signifies that MSD8-EPS is safe for skin application. The produced EPS was used to prepare a novel ointment, which was tested for wound healing ability in male albino rats. The ointment significantly (P ≤ 0.05) shortened the time needed for wound healing, as it successfully healed the wounds by 94.93% on the 7th day and completely (100%) healed the wound by the 12th day. In comparison, the control group was healed by 73.2% and 84.83%, respectively. The data confirm that the prepared ointment can safely be used for pharmaceutical wound care products.

Development of a single nucleotide polymorphism-based strain-identified method for Streptococcus thermophilus CICC 6038 and Lactobacillus delbrueckii ssp. bulgaricus CICC 6047 using pan-genomics analysis

The health benefits conferred by probiotics is specific to individual probiotic strains, highlighting the importance of identifying specific strains for research and production purposes. Streptococcus thermophilus CICC 6038 and Lactobacillus delbrueckii ssp. bulgaricus CICC 6047 are exceedingly valuable for commercial use with an excellent mixed-culture fermentation. To differentiate these 2 strains from other S. thermophilus and L. delbrueckii ssp. bulgaricus, a specific, sensitive, accurate, rapid, convenient, and cost-effective method is required. In this study, we conducted a pan-genome analysis of S. thermophilus and L. delbrueckii ssp. bulgaricus to identify species-specific core genes, along with strain-specific SNPs. These genes were used to develop suitable PCR primers, and the conformity of sequence length and unique SNPs was confirmed by sequencing for qualitative identification at the strain level. The results demonstrated that SNPs analysis of PCR products derived from these primers could distinguish CICC 6038 and CICC 6047 accurately and reproducibly from the other strains of S. thermophilus and L. delbrueckii ssp. bulgaricus, respectively. The strain-specific PCR method based on SNPs herein is universally applicable for probiotics identification. It offers valuable insights into identifying probiotics at the strain level that is fit-for-purpose in quality control and compliance assessment of commercial dairy products.

Bifidobacterium exopolysaccharides: new insights into engineering strategies, physicochemical functions, and immunomodulatory effects on host health

Bifidobacteria are a prominent type of bacteria that have garnered significant research attention for their exceptional probiotic properties and capacity to produce exopolysaccharides (EPSs). These compounds exhibit diverse physical, chemical, and biological characteristics, prompting numerous investigations into their potential applications. Researchers have noted their beneficial effects as immune modulators within the host's body across various industries. Extensive research has been conducted on the immunomodulatory effects of bifidobacteria-derived EPSs, with emerging engineering strategies aimed at enhancing their immune-modulating capabilities. Understanding the structure, physicochemical properties, and biological activities of these compounds is crucial for their effective utilization across different industries. Our review encompassed numerous studies exploring Bifidobacterium and its metabolites, including EPSs, across various sectors, drawing from diverse databases. The distinctive properties of EPSs have spurred investigations into their applications, revealing their potential to bolster the immune system, combat inflammation, and treat various ailments. Additionally, these compounds possess antioxidant and antimicrobial properties, making them suitable for incorporation into a range of products spanning food, health, and medicine.

Fermentative optimization and characterization of exopolysaccharides from Enterococcus faecium F58 isolated from traditional fresh goat cheese

This study focused on optimizing the fermentation-based production of Exopolysaccharides (EPS) from Enterococcus faecium F58 initially isolated from traditional Moroccan Jben, a fresh goat cheese. Using the central composite design, yeast extract, MnSO4, and time affect EPS concentration. The highest experimental and predicted EPS production yields were 2.46 g/L ± 0.38 and 2.86 g/L, respectively. Optimal concentrations of yeast extract (4.46 g/L) and MnSO4 (0.011 g/L) were identified after 26 h at 30 °C. Characterization of EPS was conducted using SEM with EDX, XRD, and FTIR analyses. These tests revealed a specific morphology and an amorphous structure. Additionally, thermogravimetric analysis indicated adequate EPS stability up to 200 °C with anti-adhesion properties against different pathogens. This study offers valuable insights into the optimized production of EPS from Enterococcus faecium F58, which exhibits significant structural and functional properties for various applications in the food and biotechnology industries.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01424-9.

The consequences of fermentation metabolism on the qualitative qualities and biological activity of fermented fruit and vegetable juices

Fermentation of fruit and vegetable juices with probiotics is a novel nutritional approach with potential health benefits. Lactic acid fermentation-based biotransformation results in changes in the profile and nature of bioactive compounds and improves the organoleptic properties, shelf life and bioavailability of vitamins and minerals in the fermented juices. This process has been shown to enrich the phenolic profile and bioactivity components of the juices, resulting in a new type of functional food with improved health benefits. Fruits and vegetables are the ideal substrate for microbial growth, and fruit and vegetable juice will produce rich nutrients and a variety of functional activities after fermentation, so that the high-quality utilization of fruits and vegetables is realized, and the future fermented fruit and vegetable juice products have a wide application market. This paper explores the typical fermentation methods for fruit and vegetable juices, investigates the bioactive components, functional activities, and the influence of fermentation on enhancing the quality of fruit and vegetable juices. The insights derived from this study carry significant implications for guiding the development of fermented fruit and vegetable juice industry.

Engineering strategies and applications of cyanobacterial exopolysaccharides: A review on past achievements and recent perspectives

Cyanobacteria are ideally suited for developing sustainable biological products but are underdeveloped due to a lack of genetic tools. Exopolysaccharide (EPS) is one of the essential bioproducts with widespread industrial applications. Despite their unique structural characteristics associated with distinct biological and physicochemical aspects, EPS from cyanobacteria has been underexplored. However, it is expected to accelerate in the near future due to the utilization of low-cost cyanobacterial platforms and readily available information on the structural data and specific features of these biopolymers. In recent years, cyanobacterial EPSs have attracted growing scientific attention due to their simple renewability, rheological characteristics, massive production, and potential uses in several biotechnology domains. This review focuses on the most recent research on potential new EPS producers and their distinct compositions responsible for novel biological activities. Additionally, nutritional and process parameters discovered recently for enhancing EPS production and engineering strategies applied currently to control the biosynthetic pathway for enhanced EPS production are critically highlighted. The process intensification of previously developed EPS extraction and purification processes from cyanobacterial biomass is also extensively explained. Furthermore, the newly reported biotechnological applications of cyanobacterial exopolysaccharides are also discussed.

Probiotic Characterization of LAB isolated from Sourdough and Different Traditional Dairy Products Using Biochemical, Molecular and Computational Approaches

The aim of this study was to identify and isolate lactic acid bacteria (LAB) from indigenous sourdough and dairy samples in Iran, and to assess their probiotic properties in vitro. A total of 560 potential LAB isolates were examined, and 87 demonstrated high survival rates in artificial gastrointestinal fluids without hemolytic activity. The selected isolates exhibited significant auto-aggregation (18.35 to 79.42%) and co-aggregation abilities (20.16 to 71.26%). Additionally, the isolates displayed varying degrees of cell surface hydrophobicity (12.32 to 76.24%). Results indicated that 19 LAB isolates had cholesterol assimilation rates exceeding 30%. Moreover, forty strains tested negative for all twelve assessed pathogenic genes and exhibited good adhesion to human intestinal epithelial cells (13.47 to 49.12%). Furthermore, 24 isolates formed strong biofilms, 29 formed moderate biofilms, and 23 formed weak biofilms. Except for isolates ABRIIFBI-8, ABRIIFBI-16, ABRIIFBI-23, ABRIIFBI-43, ABRIIFBI-56, and ABRIIFBI-62, most isolates were capable of producing exopolysaccharides. Consequently, LAB strains naturally occurring in sourdough and traditional dairy samples were suggested as potential probiotic candidates for incorporation into functional foods.

Structural characterization of an exopolysaccharide produced by two strains of Lacticaseibacilluscasei

Exopolysaccharides (EPSs) were isolated and purified from Lacticaseibacillus casei strains type V and RW-3703M grown under various fermentation conditions (carbon source, incubation temperature, and duration). Identical 1H NMR spectra were obtained in all cases. The molar mass determined by size-exclusion chromatography coupled with multi-angle light scattering was different for the two strains and in different culture media. The primary structure was elucidated using chemical and spectroscopic techniques. Monosaccharide and absolute configuration analyses gave the following composition: d-Glc, 1; d-Gal, 2; l-Rha, 2; d-GlcNAc, 1. Methylation analysis indicated the presence of 4-linked Glc, terminal and 6-linked Gal, terminal and 3-linked Rha, and 3,4,6-linked GlcNAc. On the basis of one- and two-dimensional 1H and 13C NMR data, the structure of the EPS was consistent with the following hexasaccharide repeating unit: {4)[Rhap(α1-3)][Galp(α1-6)]GlcpNAc(β1-6)Galp(α1-3)Rhap(β1-4)Glcp(β1-}n. Complete 1H and 13C NMR assignments are reported.

Exopolysaccharides from agriculturally important microorganisms: Conferring soil nutrient status and plant health

A wide variety of microorganisms secretes extracellular polymeric substances or commonly known as exopolysaccharides (EPS), which have been studied to influence plant growth via various mechanisms. EPS-producing microorganisms have been found to have positive effects on plant health such as by facilitating nutrient entrapment in the soil, or by improving soil quality, especially by helping in mitigating various abiotic stress conditions. The various types of microbial polysaccharides allow for the compartmentalization of the microbial community enabling them to endure undressing stress conditions. With the growing population, there is a constant need for developing sustainable agriculture where we could use various PGPR to help the plant cope with various stress conditions and simultaneously enhance the crop yield. These polysaccharides have also found application in various sectors, especially in the biomedical fields, manifesting their potential to act as antitumor drugs, play a significant role in immune evasion, and reveal various therapeutic potentials. These constitute high levels of bioactive polysaccharides which possess a wide range of implementation starting from industrial applications to novel food applications. In this current review, we aim at presenting a comprehensive study of how these microbial extracellular polymeric substances influence agricultural productivity along with their other commercial applications.

Reuterin, Phenyllactic Acid, and Exopolysaccharides as Main Antifungal Molecules Produced by Lactic Acid Bacteria: A Scoping Review

The primary goal of this scoping review is to collect, analyze, and critically describe information regarding the role of the main compounds (reuterin, phenyllactic acid, and exopolysaccharides) produced by LAB that possess antifungal properties and provide some suggestions for further research. The use of lactic acid bacteria (LAB) to mitigate spoilage and extend the shelf life of foodstuffs has a long history. Recently, there has been a growing interest in the unique properties of these additions to the foodstuffs in which they are applied. In recent studies regarding biopreservation, significant attention has been given to the role of these microorganisms and their metabolites. This fascinating recent discipline aims not only to replace traditional preservation systems, but also to improve the overall quality of the final product. The biologically active by-products produced by lactic acid bacteria are synthesized under certain conditions (time, temperature, aerobiosis, acidity, water activity, etc.), which can be enacted through one of the oldest approaches to food processing: fermentation (commonly used in the dairy and bakery sectors). This study also delves into the biosynthetic pathways through which they are synthesized, with a particular emphasis on what is known about the mechanisms of action against molds in relation to the type of food.

The Involvement of Lactic Acid Bacteria and Their Exopolysaccharides in the Biosorption and Detoxication of Heavy Metals in the Gut

Heavy metal pollution has become one of the most important global environmental issues. The human health risk posed by heavy metals encountered through the food chain and occupational and environmental exposure is increasing, resulting in a series of serious diseases. Ingested heavy metals might disturb the function of the gut barrier and cause toxicity to organs or tissues in other sites of the body. Probiotics, including some lactic acid bacteria (LAB), can be used as an alternative strategy to detoxify heavy metals in the host body due to their safety and effectiveness. Exopolysaccharides (EPS) produced by LAB possess varied chemical structures and functional properties and take part in the adsorption of heavy metals via keeping the producing cells vigorous. The main objective of this paper was to summarize the roles of LAB and their EPS in the adsorption and detoxification of heavy metals in the gut. Accumulated evidence has demonstrated that microbial EPS play a pivotal role in heavy metal biosorption. Specifically, EPS-producing LAB have been reported to show superior absorption, tolerance, and efficient abatement of the toxicity of heavy metals in vitro and/or in vivo to non-EPS-producing species. The mechanisms underlying EPS-metal binding are mainly related to the negatively charged acidic groups and unique steric structure on the surface of EPS. However, whether the enriched heavy metals on the bacterial cell surface increase toxicity to local mammal cells or tissues in the intestine and whether they are released during excretion remain to be elucidated.

Anti-Obesity Effect of Kimchi with Starter Cultures in 3T3-L1 Cells

Lactic acid bacteria (LAB) isolated from kimchi have various functions, including antioxidant, anti-inflammation, and anti-obesity activities, and are therefore widely used in the food, pharmaceutical, and medical fields. To date, the health functionalities of LAB have been widely reported; however, those of kimchi fermented with LAB as a starter have rarely been reported. Therefore, research on the selection of LAB with anti-obesity activity and the health functionality of kimchi fermented with LAB is needed. In the present study, LAB with anti-obesity activity were initially selected by measuring the Oil-Red O intensity. Among the four LAB strains, anti-obesity activity was confirmed by measuring cell viability, lipid levels, and lipid accumulation. Then, starter kimchi (SK) was prepared by inoculating selected LABs, and its pH, total acidity, and salinity were compared with those of naturally fermented kimchi (NK). Lastly, anti-obesity activity was also investigated in 3T3-L1 cells. Selected LAB showed no cytotoxicity up to 107 CFU/ml, with Lactobacillus brevis JC7 and Leuconostoc mesenteroides KCKM0828 having higher inhibitory effects on TG, TC content and lipid accumulation. Most SKs showed fermentation properties similar to those of the NK. SKs showed no cytotoxicity at concentrations of up to 1,000 μg/ml. SKs showed strong inhibitory effects on TG content, lipid accumulation, and obesity-related gene and protein expressions. Taken together, the utilization of LAB as a starter could improve the health benefits of kimchi.

Enhancing nutritional and sensory properties of plant-based beverages: a study on chickpea and Kamut® flours fermentation using Lactococcus lactis

The study aimed to set up a protocol for the production of a clean-label plant-based beverage (PBB), obtained by mixing chickpeas and Kamut® flours and using a commercial Lactococcus lactis (LL) as fermentation starter, and to characterize it, from nutritional, microbiological, textural, shelf-life, and sensory points of view. The effect of using the starter was evaluated comparing the LL-PBB with a spontaneously fermented beverage (CTRL-PBB). Both PBBs were high in proteins (3.89/100 g) and could be considered as sources of fiber (2.06/100 g). Notably, L. lactis fermentation enhanced the phosphorus (478 vs. 331 mg/kg) and calcium (165 vs. 117 mg/kg) concentrations while lowering the raffinose content (5.51 vs. 5.08 g/100 g) compared to spontaneous fermentation. Cell density of lactic acid bacteria increased by ca. two log cycle during fermentation of LL-PBB, whereas undesirable microbial groups were not detected. Furthermore, L. lactis significantly improved the beverage's viscosity (0.473 vs. 0.231 Pa s), at least for 10 days, and lightness. To assess market potential, we conducted a consumer test, presenting the LL-PBB in "plain" and "sweet" (chocolate paste-added) variants. The "sweet" LL-PBB demonstrated a higher acceptability score than its "plain" counterpart, with 88 and 78% of participants expressing acceptability and a strong purchase intent, respectively. This positive consumer response positions the sweet LL-PBB as a valuable, appealing alternative to traditional flavored yogurts, highlighting its potential in the growing plant-based food market.

Characteristics of Lactic Acid Bacteria as Potential Probiotic Starters and Their Effects on the Quality of Fermented Sausages

The aim of this study was to explore the potential of commercial lactic acid bacteria (LAB) as probiotic starters in fermented sausages. We initially investigated the growth activity, acid production capability, and tolerance to fermentation conditions of Lactobacillus sakei, Lactiplantibacillus plantarum, and Pediococcus pentosaceus. All three LAB strains proved viable as starters for fermented sausages. Subsequently, we explored their potential as probiotics based on their antibacterial and antioxidant capabilities. L. plantarum exhibited stronger inhibition against Escherichia coli and Staphylococcus aureus. All three strains displayed antioxidant abilities, with cell-free supernatants showing a higher antioxidant activity compared to intact cells and cell-free extracts. Moreover, the activities of superoxide dismutase, glutathione peroxidase, and catalase were stronger in the cell-free supernatant, cell-free extract, and intact cell, respectively. Finally, we individually and collectively inoculated these three LAB strains into sausages to investigate their impact on quality during the fermentation process. External starters significantly reduced pH, thiobarbituric acid reactive substances, and sodium nitrite levels. The improvements in color and texture had positive effects, with the L. plantarum inoculation achieving higher sensory scores. Overall, all three LAB strains show promise as probiotic fermentation starters in sausage production.

Characterization of a Novel Polysaccharide Derived from Rhizospheric Paecilomyces vaniformisi and Its Mechanism for Enhancing Salinity Resistance in Rice Seedlings

Soil salinity is an important limiting factor in agricultural production. Rhizospheric fungi can potentially enhance crop salinity tolerance, but the precise role of signaling substances is still to be systematically elucidated. A rhizospheric fungus identified as Paecilomyces vaniformisi was found to enhance the salinity tolerance of rice seedlings. In this study, a novel polysaccharide (PPL2b) was isolated from P. vaniformisi and identified as consisting of Manp, Glcp, GalpA, and Galp. In a further study, PPL2b showed significant activity in alleviating salinity stress-induced growth inhibition in rice seedlings. The results indicated that under salinity stress, PPL2b enhances seed germination, plant growth (height and biomass), and biochemical parameters (soluble sugar and protein contents). Additionally, PPL2b regulates genes such as SOS1 and SKOR to decrease K+ efflux and increase Na+ efflux. PPL2b increased the expression and activity of genes related to antioxidant enzymes and nonenzyme substances in salinity-induced oxidative stress. Further study indicated that PPL2b plays a crucial role in regulating osmotic substances, such as proline and betaine, in maintaining the osmotic balance. It also modulates plant hormones to promote rice seedling growth and enhance their tolerance to soil salinity. The variables interacted and were divided into two groups (PC1 77.39% and PC2 18.77%) based on their relative values. Therefore, these findings indicate that PPL2b from P. vaniformisi can alleviate the inhibitory effects of salinity stress on root development, osmotic adjustment, ion balance, oxidative stress balance, and growth of rice seedlings. Furthermore, it suggests that polysaccharides produced by rhizospheric fungi could be utilized to enhance crop tolerance to salinity.

Bioactive Ingredients from Dairy-Based Lactic Acid Bacterial Fermentations for Functional Food Production and Their Health Effects

Lactic acid bacteria are traditionally applied in a variety of fermented food products, and they have the ability to produce a wide range of bioactive ingredients during fermentation, including vitamins, bacteriocins, bioactive peptides, and bioactive compounds. The bioactivity and health benefits associated with these ingredients have garnered interest in applications in the functional dairy market and have relevance both as components produced in situ and as functional additives. This review provides a brief description of the regulations regarding the functional food market in the European Union, as well as an overview of some of the functional dairy products currently available in the Irish and European markets. A better understanding of the production of these ingredients excreted by lactic acid bacteria can further drive the development and innovation of the continuously growing functional food market.

Fecal fermentation and high-fat diet-induced obesity mouse model confirmed exopolysaccharide from Weissella cibaria PFY06 can ameliorate obesity by regulating the gut microbiota

Obesity associated with diet and intestinal dysbiosis is a worldwide public health crisis, and exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) have prebiotic potential to ameliorate obesity. Therefore, the present study obtained LAB with the ability to produce high EPS, examined the structure of EPS, and explained its mechanism of alleviating obesity by in vivo and in vitro models. The results showed that Weissella cibaria PFY06 with a high EPS yield was isolated from strawberry juice, and pure polysaccharide (PFY06-EPS) was purified by Sephadex G-100. The structural characteristics of PFY06-EPS showed that the molecular weight was 8.08 × 10⁶ Da and composed of α-(1,6)-D glucosyl residues. An in vitro simulated human colon fermentation test demonstrated that PFY06-EPS increased the abundance of Prevotella and Bacteroides. Cell tests confirmed that PFY06-EPS after fecal fermentation inhibited fat accumulation by promoting the secretion of endogenous gastrointestinal hormones and insulin and inhibiting the secretion of inflammatory factors. Notably, PFY06-EPS reduced weight gain, fat accumulation, inflammatory reactions and insulin resistance in a high-fat diet-induced obesity mouse model and improved glucolipid metabolism. PFY06-EPS intervention reversed obesity-induced microflora disorders, such as reducing the Firmicutes/Bacteroides ratio and increasing butyrate-producing bacteria (Roseburia and Oscillibacter), and reduced endotoxemia to maintain intestinal barrier integrity. Therefore, in vivo and in vitro models showed that PFY06-EPS had potential as a prebiotic that may play an anti-obesity role by improving the function of the gut microbiota.

Steps toward a digital twin for functional food production with increased health benefits

Lactobacillus rhamnosus (L. rhamnosus) is a commensal bacterium with health-promoting properties and with a wide range of applications within the food industry. To improve and optimize the control of L. rhamnosus biomass production in batch and fed-batch bioprocesses, this study proposes the application of artificial neural network (ANN) modelling to improve process control and monitoring, with potential future implementation as a basis for a digital twin. Three ANNs were developed using historical data from ten bioprocesses. These ANNs were designed to predict the biomass in batch bioprocesses with different media compositions, predict biomass in fed-batch bioprocesses, and predict the growth rate in fed-batch bioprocesses. The immunomodulatory effect of the L. rhamnosus samples was examined and found to elicit an anti-inflammatory response as evidenced by the inhibition of IL-6 and TNF-α secretion. Overall, the findings of this study reinforce the potential of ANN modelling for bioprocess optimization aimed at improved control for maximising the volumetric productivity of L. rhamnosus as an immunomodulatory agent with applications in the functional food industry.

Production of GABA in milk fermented by Bifidobacterium adolescentis strains selected on the bases of their technological and gastrointestinal performance

There is an increasing interest in producing foods enriched in gamma-aminobutyric acid (GABA), due to their purported health promoting attributes. GABA is the main inhibitor neurotransmitter of the central nervous system, and several microbial species are capable to produce it through decarboxylation of glutamate. Among them, several lactic acid bacteria species have been previously investigated as an appealing alternative to produce GABA enriched foods via microbial fermentation. In this work we report for the first time an investigation into the possibility of utilizing high GABA-producing Bifidobacterium adolescentis strains as a mean to produce fermented probiotic milks naturally enriched in GABA. To this end, in silico and in vitro analyses were conducted in a collection of GABA-producing B. adolescentis strains, with the main goal to scrutinize their metabolic and safety traits, including antibiotic resistance patterns, as well as their technological robustness and performance to survive a simulated gastrointestinal passage. One of the strains, IPLA60004, exhibited better survival to lyophilization and cold storage (for up to 4 weeks at 4 °C), as well as survival to gastrointestinal passage, as compared to the other strains under investigation. Besides, the elaboration of milk drinks fermented with this strain, yielded products with the highest GABA concentration and viable bifidobacterial cell counts, achieving conversion rates of the precursor, monosodium glutamate (GMS), up to 70 %. To our knowledge, this is the first report on the elaboration of GABA enriched milks through fermentation with B. adolescentis.

Enhanced probiotic potential of Lactobacillus kefiranofaciens OSU-BDGOA1 through co-culture with Kluyveromyces marxianus bdgo-ym6

Introduction

Due to the increasing consumer demand for the development and improvement of functional foods containing probiotics, new probiotic candidates need to be explored as well as novel means to enhance their beneficial effects. Lactobacillus kefiranofaciens OSU-BDGOA1 is a strain isolated from kefir grains that has demonstrated probiotic traits. This species is the main inhabitant of kefir grains and is responsible for the production of an exopolysaccharide (EPS) whit vast technological applications and potential bioactivities. Research has shown that interkingdom interactions of yeast and lactic acid bacteria can enhance metabolic activities and promote resistance to environmental stressors.

Methods

Comparative genomic analyses were performed to distinguish OSU-BDGOA1 from other strains of the same species, and the genome was mined to provide molecular evidence for relevant probiotic properties. We further assessed the cumulative effect on the probiotic properties of OSU-BDGOA1 and Kluyveromyces marxianus bdgo-ym6 yeast co-culture compared to monocultures.

Results

Survival during simulated digestion assessed by the INFOGEST digestion model showed higher survival of OSU-BDGOA1 and bdgo-ym6 in co-culture. The adhesion to intestinal cells assessed with the Caco-2 intestinal cell model revealed enhanced adhesion of OSU-BDGOA1 in co-culture. The observed increase in survival during digestion could be associated with the increased production of EPS during the late exponential and early stationary phases of co-culture that, by enhancing co-aggregation between the yeast and the bacterium, protects the microorganisms from severe gastrointestinal conditions as observed by SEM images. Immune modulation and barrier function for recovery and prevention of flagellin-mediated inflammation by Salmonella Typhimurium heat-killed cells (HKSC) in Caco-2 cells were also measured. OSU-BDGOA1 in mono- and co-culture regulated inflammation through downregulation of pro-inflammatory cytokine expression and increased membrane barrier integrity assessed by TEER, FD4 permeability, and expression of tight junctions.

Discussion

The results of the study warrant further research into the application of co-cultures of yeast and LAB in functional probiotic products and the potential to increase EPS production by co-culture strategies.

Targeted Application of Functional Foods as Immune Fitness Boosters in the Defense against Viral Infection

In recent times, the emergence of viral infections, including the SARS-CoV-2 virus, the monkeypox virus, and, most recently, the Langya virus, has highlighted the devastating effects of viral infection on human life. There has been significant progress in the development of efficacious vaccines for the prevention and control of viruses; however, the high rates of viral mutation and transmission necessitate the need for novel methods of control, management, and prevention. In recent years, there has been a shift in public awareness on health and wellbeing, with consumers making significant dietary changes to improve their immunity and overall health. This rising health awareness is driving a global increase in the consumption of functional foods. This review delves into the benefits of functional foods as potential natural means to modulate the host immune system to enhance defense against viral infections. We provide an overview of the functional food market in Europe and discuss the benefits of enhancing immune fitness in high-risk groups, including the elderly, those with obesity, and people with underlying chronic conditions. We also discuss the immunomodulatory mechanisms of key functional foods, including dairy proteins and hydrolysates, plant-based functional foods, fermentates, and foods enriched with vitamin D, zinc, and selenium. Our findings reveal four key immunity boosting mechanisms by functional foods, including inhibition of viral proliferation and binding to host cells, modulation of the innate immune response in macrophages and dendritic cells, enhancement of specific immune responses in T cells and B cells, and promotion of the intestinal barrier function. Overall, this review demonstrates that diet-derived nutrients and functional foods show immense potential to boost viral immunity in high-risk individuals and can be an important approach to improving overall immune health.

A Comprehensive Review of Bioactive Compounds from Lactic Acid Bacteria: Potential Functions as Functional Food in Dietetics and the Food Industry

Lactic acid bacteria (LAB) are beneficial microbes known for their health-promoting properties. LAB are well known for their ability to produce substantial amounts of bioactive compounds during fermentation. Peptides, exopolysaccharides (EPS), bacteriocins, some amylase, protease, lipase enzymes, and lactic acid are the most important bioactive compounds generated by LAB activity during fermentation. Additionally, the product produced by LAB is dependent on the type of fermentation used. LAB derived from the genera Lactobacillus and Enterococcus are the most popular probiotics at present. Consuming fermented foods has been previously connected to a number of health-promoting benefits such as antibacterial activity and immune system modulation. Furthermore, functional food implementations lead to the application of LAB in therapeutic nutrition such as prebiotic, immunomodulatory, antioxidant, anti-tumor, blood glucose lowering actions. Understanding the characteristics of LAB in diverse sources and its potential as a functional food is crucial for therapeutic applications. This review presents an overview of functional food knowledge regarding interactions between LAB isolated from dairy products (dairy LAB) and fermented foods, as well as the prospect of functioning LAB in human health. Finally, the health advantages of LAB bioactive compounds are emphasized.

Optimization, fractional characterization, and antioxidant potential of exopolysaccharides from Levilactobacillus brevis NCCP 963 isolated from "kanji"

A novel exopolysaccharide (EPS) was obtained from Levilactobacillus brevis NCCP 963 isolated from a black carrot drink named "kanji". The culture conditions for maximum EPS yield were explored by the Plackett-Burman (PB) design and response surface methodology (RSM) along with the fractional characterization and antioxidant potential of EPSs. The PB design screened out five significant factors, namely, glucose, sucrose, tryptone, CaCl₂, and di-potassium phosphate out of eleven independent factors. The RSM indicated glucose and CaCl₂ as significant factors in EPS production and a maximum EPS production of 968.89 mg L^-1 was obtained at optimized levels of 10.56% glucose, 9.23% sucrose, 0.75% tryptone, 0.446% CaCl₂, and 0.385% K₂HPO₄. A R² value above 93% indicates higher variability, depicting the validity of the model. The obtained EPS has a molecular weight of 5.48 × 10⁴ Da and is a homopolysaccharide in nature with glucose monosaccharides. FT-IR analysis showed significant band stretching of C-H, O-H, C-O and C-C and indicated the β-glucan nature of EPSs. The comprehensive antioxidant investigation showed significant in vitro DPPH, ABTS, hydroxyl, and superoxide scavenging capacity with EC₅₀ values of 1.56, 0.31, 2.1, and 6.7 mg mL^-1 respectively. Curd formation from the resulting strain prevented syneresis.

Paraprobiotics and Postbiotics-Current State of Scientific Research and Future Trends toward the Development of Functional Foods

The potential of paraprobiotics and postbiotics to be used as beneficial agents for human health has caused an effort by the scientific community to gather information about the bioactivity of these compounds and production methods. Understanding the evolution of scientific research in this area of study is important to understand the future perspectives and the main bottlenecks of scientific and technological development involving these compounds. In this scenario, this review work used a bibliometric analysis tool intending to improve the scientific documentation, bringing information and communicating the results to the scientific community through the quantitative analysis of the current literature, available in one of the main databases, the Web of Science, also providing recent information on the evolution and future perspectives in the field of paraprobiotic and postbiotic development. The results of this study showed that the main studies discuss the bioactivity of these compounds. Concerning the development of functional foods, there is a need for extensive research on production methods and the interaction of these compounds with food. However, it concluded that much still needs to be studied to prove the claims of bioactivity, especially when used for the development of functional foods.

Exopolysaccharides Producing Bacteria: A Review

Bacterial exopolysaccharides (EPS) are essential natural biopolymers used in different areas including biomedicine, food, cosmetic, petroleum, and pharmaceuticals and also in environmental remediation. The interest in them is primarily due to their unique structure and properties such as biocompatibility, biodegradability, higher purity, hydrophilic nature, anti-inflammatory, antioxidant, anti-cancer, antibacterial, and immune-modulating and prebiotic activities. The present review summarizes the current research progress on bacterial EPSs including their properties, biological functions, and promising applications in the various fields of science, industry, medicine, and technology, as well as characteristics and the isolation sources of EPSs-producing bacterial strains. This review provides an overview of the latest advances in the study of such important industrial exopolysaccharides as xanthan, bacterial cellulose, and levan. Finally, current study limitations and future directions are discussed.

Properties of Yoghurt Fortified in Lactoferrin with Effect of Storage Time

The stability of fortified yoghurts during refrigerated storage is important for industry and the consumer. The aim of the study was to evaluate the nutritional value, microbiological quality, organoleptic properties, and structure of natural yoghurts made with the addition of lactoferrin during refrigerated storage. In this study, we produced natural yoghurts fortified in lactoferrin, using YC-X11 yoghurt starter culture based on Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Physicochemical (acidity, nutritional value and structure) as well as microbiological and organoleptic changes occurring during 28-days refrigerated storage were determined. Storage research made it possible to determine the direction of changes taking place in the products. The analysed parameters did not differ statistically significantly between the control yoghurts and those with the addition of lactoferrin. Textural and rheological studies also shown that the addition of lactoferrin did not significantly change the structure of the yoghurt. The yoghurts were characterized by high sanitary and hygienic quality during the whole refrigerated storage. Lactoferrin has a positive effect on the durability of the product.

Exopolysaccharide-mediated silver nanoparticles synthesized from Lactobacillus paracasei with antimicrobial, antibiofilm and antioxidant activities

Biofilm formation and resistance to antibiotics in pathogenic bacteria are important concerns in the treatment of infectious diseases. A new rapid, eco-friendly and cost-effective strategy to overcome these problems is the use of microbial exopolysaccharides (EPS) for green synthesis of various metal nanoparticles (NPs). This study used EPS from a native probiotic Lactobacillus isolate to synthesize silver nanoparticles (AgNPs) with effective antimicrobial, antibiofilm and antioxidant properties. AgNPs were synthesized by 10 mg of EPS of Lactobacillus paracasei (L. paracasei MN₈₀₉₅₂₈) isolated from a local yogurt. The characteristics of EPS AgNPs were confirmed using UV-VIS, FT-IR, DLS, XRD, EDX, FE-SEM, and zeta potential. Antimicrobial, antibiofilm and antioxidant activities of EPS AgNPs were evaluated by the agar well diffusion, microtiter dilution, SEM electron microscopy, and DPPH radical absorption methods, respectively. Spectroscopy data indicated the presence of a 466-nm peak as a feature of AgNPs. FT-IR confirmed the presence of biological agents in the synthesis of AgNPs. FE-SEM results showed that the synthesized AgNPs had a spherical shape with the size of 33-38 nm. Synthesized AgNPs at a concentration of 100 mg/ml demonstrated a significant inhibitory activity compared to chemically synthesized AgNPs. These NPs, exhibited the greatest effect of inhibiting the Escherichia coli and Pseudomonas aeruginosa biofilm formation at sub-MIC concentration, and the best effect of DPPH radical as antioxidant activity was determined at 50-μg/ml concentration. Our findings reveal that EPS AgNPs synthesized by the native isolate of L. paracasei (MN₈₀₉₅₂₈) is an inexpensive and environment-friendly candidate for application in pharmaceuticals fields.

Biopolymers Produced by Lactic Acid Bacteria: Characterization and Food Application

Plants, animals, bacteria, and food waste are subjects of intensive research, as they are biological sources for the production of biopolymers. The topic links to global challenges related to the extended life cycle of products, and circular economy objectives. A severe and well-known threat to the environment, the non-biodegradability of plastics obliges different stakeholders to find legislative and technical solutions for producing valuable polymers which are biodegradable and also exhibit better characteristics for packaging products. Microorganisms are recognized nowadays as exciting sources for the production of biopolymers with applications in the food industry, package production, and several other fields. Ubiquitous organisms, lactic acid bacteria (LAB) are well studied for the production of exopolysaccharides (EPS), but much less as producers of polylactic acid (PLA) and polyhydroxyalkanoates (PHAs). Based on their good biodegradability feature, as well as the possibility to be obtained from cheap biomass, PLA and PHAs polymers currently receive increased attention from both research and industry. The present review aims to provide an overview of LAB strains' characteristics that render them candidates for the biosynthesis of EPS, PLA, and PHAs, respectively. Further, the biopolymers' features are described in correlation with their application in different food industry fields and for food packaging. Having in view that the production costs of the polymers constitute their major drawback, alternative solutions of biosynthesis in economic terms are discussed.

Carbohydrate esterases involved in deacetylation of food components by the human gut microbiota

Non-carbohydrate modifications such as acetylations are widespread in food stuffs as well as they play important roles in diverse biological processes. These modifications meet the gut environment and are removed from their carbohydrate substrates by the resident microbiota. Among the most abundant modifications are O-acetylations, contributing to polysaccharides physico-chemical properties such as viscosity and gelling ability, as well as reducing accessibility for glycosyl hydrolases, and thus hindering polysaccharide degradation. Of particular note, O-acetylations increase the overall complexity of a polymer, thus requiring a more advanced degrading machinery for microbes to utilize it. This minireview describes acetylesterases from the gut microbiota that deacetylate various food polysaccharides, either as natural components of food, ingredients, stabilizers of microbial origin, or as part of microbes for food and beverage preparations. These enzymes include members belonging to at least 8 families in the CAZy database, as well as a large number of biochemically characterized esterases that have not been classified yet. Despite different structural folds, most of these acetylesterases have a common acid-base mechanism and belong to the SGNH hydrolase superfamily. We highlight examples of acetylesterases that are highly specific to one substrate and to the position of the acetyl group on the glycosyl residue of the carbohydrate, while other members that have more broad substrate specificity. Current research aimed at unveiling the functions and regioselectivity of acetylesterases will help providing fundamental mechanistic understanding on how dietary components are utilized in the human gut and will aid developing applications of these enzymes to manufacture novel industrial products.

The Space Environment Activates Capsular Polysaccharide Production in Lacticaseibacillus rhamnosus Probio-M9 by Mutating the wze (ywqD) Gene

The study of microorganisms in outer space has focused mainly on investigating phenotypic changes in microbial pathogens induced by factors encountered in space. This study aimed to investigate the effect of space exposure on a probiotic bacterium, Lacticaseibacillus rhamnosus Probio-M9. Probio-M9 cells were exposed to space in a spaceflight. Interestingly, our results showed that a substantial proportion of space-exposed mutants (35/100) exhibited a ropy phenotype, characterized by their larger colony sizes and an acquired ability to produce capsular polysaccharide (CPS), compared with the original Probio-M9 or the ground control isolates without space exposure. Whole-genome sequencing analyses on both the Illumina and PacBio platforms revealed a skewed distribution of single nucleotide polymorphisms (12/89 [13.5%]) toward the CPS gene cluster, particularly in the wze (ywqD) gene. The wze gene encodes a putative tyrosine-protein kinase that regulates CPS expression through substrate phosphorylation. Transcriptomics analysis of two space-exposed ropy mutants revealed increased expression in the wze gene relative to a ground control isolate. Finally, we showed that the acquired ropy phenotype (CPS-producing ability) and space-induced genomic changes could be stably inherited. Our findings confirmed that the wze gene directly influences the capacity for CPS production in Probio-M9, and space mutagenesis is a potential strategy for inducing stable physiological changes in probiotics. IMPORTANCE This work investigated the effect of space exposure on a probiotic bacterium, Lacticaseibacillus rhamnosus Probio-M9. Interestingly, the space-exposed bacteria became capable of producing capsular polysaccharide (CPS). Some probiotic-derived CPSs have nutraceutical potential and bioactive properties. They also enhance the survival of probiotics through the gastrointestinal transit and ultimately strengthen the probiotic effects. Space mutagenesis seems to be a promising strategy for inducing stable changes in probiotics, and the obtained high-CPS-yielding mutants are valuable resources for future applications.

METABOLITE PROFILING, HYPOLIPIDEMIC, and ANTI-ATHEROSCLEROSIS ACTIVITY of MIXED VEGETABLE FERMENTATION EXTRACT

Although positive association between fermented vegetables intake with the risk of coronary heart disease (CHD) has increased attention nowadays, the metabolite profiling and the mechanism of action are still elusive. This study designed to investigate the secondary metabolites, hypolipidemic, and anti-atherogenic effect of mixed vegetable fermentation extract (MVFE). The metabolite screening of the MVFE was assessed using the Liquid Chromatography Tandem Mass Spectrophotometer (LC-MS/MS) method. The result of LC-MS/MS was used as ligands to inhibit the binding of oxidized LDL (oxLDL) and Cluster Differentiation 36 (CD36), Scavenger Receptor A1 (SRA1), Lectin-type oxidized LDL receptor 1 (LOX1). This work was performed with molecular docking using Discovery Studio 2021, PyRx 0.9, and Autodock Vina 4.2 followed by analyzing Network Pharmacology, Protein Protein Interaction (PPI) using Cytoscape 3.9.1 and String 2.0.0. Finally, the clinical effect of MVFE was evaluated using in vivo study. Twenty rabbits were assigned to normal, negative control, and MVFE group that were fed with standard diet, high fat diet (HFD), HFD supplemented with MVFE 100, 200 mg/kg BW, respectively. The serum level of Total Cholesterol (TC) and Low-Density Lipoprotein (LDL-c) were detected at the end of week 4. The LC-MS/MS analysis identified 17 compounds categorized as peptides, fatty acids, polysaccharides, nucleoside, flavonoids, flavanols, and phenolic compounds. Based on the docking study, more negative binding affinity was observed in the interaction between metabolites with the scavenger receptors (SR) than simvastatin. The number of nodes and edges based on Network Pharmacology analysis were 268 and 482, respectively. The PPI network showed that MVFE metabolites exerts its athero-protective effect by modulating various cellular processes including inflammation, improvement of endothelial function, and modulation of lipid metabolism. Blood TC and LDL-c concentrations in the negative control (458.82 ± 82.03; 191.87 ± 92.16 mg/dL) were higher significantly compared to the normal group (87.03 ± 29.27; 43.33 ± 5.75 mg/dL). The MVFE administration decreased the TC (100, 200 mg/kg BW MVFE: 269.96 ± 85.34; 130.17 ± 45.02 mg/dL) and LDL-c level (100, 200 mg/kg BW MVFE = 87.24 ± 22.85; 41.82 ± 11.08 mg/dL) dose-dependently (p < 0,001). The secondary metabolites derived from fermented mixed vegetables extract might be developed as a potential strategy to prevent CHD by targeting the multiple pathways in atherosclerosis.

Probiotic Properties of Exopolysaccharide-Producing Bacteria from Natto

Natto is a traditional Japanese food made from soybeans fermented with Bacillus subtilis var. natto. It is also a famous food in Thailand. Potential probiotics were screened from natto. Bacillus subtilis strain VN5 produced the most quantity of exopolysaccharide (EPS), so it was selected to study the properties of microbial EPS and probiotics. The Fourier transform infrared spectrometer or FT-IR spectroscopy confirmed the presence of carboxyl and hydroxyl groups. The patterns of FT-IR and levans are similar. The basic properties of probiotics were revealed. The 90% of VN5 strain resisted lysozyme within 30 min. VN5 survived under acidic conditions (pH 1-6), and the survival rate in 0.3%, 0.5%, and 1% bile solutions for 24 h was 100%. Unfortunately, VN5 did not inhibit the growth of Escherichia coli, Staphylococcus aureus, and Salmonella typhi. Gamma hemolysis was determined in VN5 strain. The finding on Bacillus subtilis strain (VN5) from natto paves the way to a high potential, useful new strain of probiotics.

Effects of a Lactobacillus fermentation product on the fecal characteristics, fecal microbial populations, immune function, and stress markers of adult dogs

The objective of this study was to measure the effects of a Lactobacillus fermentation product (LBFP) on fecal characteristics and microbiota, blood biomarkers, immune function, and serum oxidative stress markers of adult dogs. Thirty adult beagle dogs [23 M, 7 F; mean age = 8.47 ± 2.65 yr old; mean BW = 15.43 ± 4.17 kg] were used in a completely randomized design study. All dogs were fed a basal diet to maintain BW for 5 wk, followed by baseline blood and fecal sample collections. Dogs remained on the same diet, but then were randomly assigned to a placebo (dextrose) or LBFP supplement (Limosilactobacillus fermentum and Lactobacillus delbrueckii). Both treatments were dosed at 4 mg/kg BW via gelatin capsule for 5 wk (n = 15/treatment). Fecal and blood samples were collected at that time. Change from baseline data were analyzed using the Mixed Models procedure of SAS 9.4, with P < 0.05 being significant and P < 0.10 being trends. Most circulating metabolites and immunoglobulins (Ig) were unaltered by treatment, but LBFP-supplemented dogs had lower changes in serum corticosteroid isoenzyme of alkaline phosphatase (P < 0.05), alanine aminotransferase (P < 0.10), and IgM (P < 0.10) than controls. The change in fecal scores tended to be lower (P = 0.068) in LBFP-supplemented dogs than controls, signifying firmer feces in LBFP-supplemented dogs. Regarding the fecal microbiota, alpha diversity indicators tended to be higher (P = 0.087) in LBFP-supplemented dogs than controls. One fecal bacterial phylum (Actinobacteriota) was altered by treatments, with its relative abundance tending to have a greater (P < 0.10) increase in controls than LBFP-supplemented dogs. Fifteen bacterial genera were altered (P < 0.05 or P < 0.10) by treatments, including relative abundances of fecal Peptoclostridium, Sarcina, and Faecalitalea that had a greater (P < 0.05) increase in controls than LBFP-supplemented dogs. In contrast, relative abundances of fecal Faecalibaculum, Bifidobacterium, and uncultured Butyricicoccaceae had a greater (P ≤ 0.05) increase in LBFP-supplemented dogs than controls. After week 5, dogs underwent transport stress (45-min vehicle ride) to assess oxidative stress markers. The change in serum superoxide dismutase after transport had a greater (P < 0.0001) increase in LBFP-supplemented dogs than controls. Our data suggest that LBFP may provide benefits to dogs by stabilizing stool quality, beneficially shifting fecal microbiota, and protecting against oxidative damage when subjected to stress.

Structural, antioxidant, and immunomodulatory activities of an acidic exopolysaccharide from Lactiplantibacillus plantarum DMDL 9010

This study investigated the structural, antioxidant, and immunomodulatory activities of acidic exopolysaccharide (EPS-LP2) isolated from Lactiplantibacillus plantarum DMDL 9010. EPS-LP2 is composed of fucose (Fuc), arabinose (Ara), galactose (Gal), glucose (Glc), mannose (Man), and D-fructose (Fru) with a molar ratio of 0.13: 0.69: 8.32: 27.57: 62.07: 0.58: 0.46, respectively. Structural analysis of EPS-LP2 exhibited a smooth irregular lamellar surface, rod-like structure with swollen ends and slippery surfaces, and good thermal stability. Based on the methylation and NMR analysis, sugar residues including t-Manp, t-Glcp, 2-Manp, 6-Galp, 6-Glcp, and 4-Glcp were found to exist in EPS-LP2. In the 50∼400 μg/ml range, EPS-LP2 showed negligible neurotoxicity to RAW264.7 cells. Moreover, EPS-LP2 could protect RAW264.7 cells from oxidative injury by lowering the generation of reactive oxygen species (ROS), malondialdehyde (MDA), and the secretion of lactate dehydrogenase (LDH). In contrast, an increase in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and the concentrations of glutathione (GSH) were observed. Immunoreactivity assays showed that EPS-LP2 could suppress the expression of NO, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) and inhibit the activation of the mitogen-activated protein kinase (MAPK)/nuclear factor-κB-gene binding (NF-κB) cell pathway. Conclusively, EPS-LP2 could be a potential natural antioxidant and immunomodulatory agent in functional foods and medicines.

Improvement of the Lyophilization Survival Rate of Lactobacillus casei via Regulation of Its Surface Substances

The influence of surface substance production on the freeze-drying survival of Lactobacillus casei and methods to control the surface substances during fermentation were studied. The bacteria were treated with hypertonicity combined with ultrasound, and the survival rate was determined. The optimal conditions for removing surface substance without harming the bacteria were 81 w/18 min. The surface substances provided a protective effect on the lyophilization of the bacteria without protectants. However, in the presence of protectants, excessive surface substances reduced the protective effect of the optimum protectant alginate to 39.69 ± 1.27%. Finally, the amount of surface substances and lyophilized survival rate of collected bacteria were determined by adding EDTA during fermentation and regulating fermentation conditions, such as the carbon source, carbon-to-nitrogen ratio, and pH. The highest survival rate was 85.79 ± 3.29%, which was achieved when the amount of surface substances was (2.82 ± 0.55) × 10−11 mg/CFU. Therefore, the production of surface substances by the bacteria could be reduced by modifying the fermentation stage, which has significance in the improvement of the lyophilization survival rate of L. casei and the number of live bacteria per unit mass of L. casei in the lyophilized preparation.