Metabolic Regulation of Longevity and Immune Response in Caenorhabditis elegans by Ingestion of Lacticaseibacillus rhamnosus IDCC 3201 Using Multi-Omics Analysis.

Probiotics, specifically Lacticaseibacillus rhamnosus, have garnered attention for their potential health benefits. This study focuses on evaluating the probiotic properties of candidate probiotics L. rhamnosus IDCC 3201 (3201) using the Caenorhabditis elegans surrogate animal model, a well-established in vivo system for studying host-bacteria interactions. The adhesive ability to the host's gastrointestinal tract is a crucial criterion for selecting potential probiotic bacteria. Our findings demonstrated that 3201 exhibits significantly higher adhesive capabilities compared with Escherichia coli OP50 (OP50), a standard laboratory food source for C. elegans and is comparable with the widely recognized probiotic L. rhamnosus GG (LGG). In lifespan assay, 3201 significantly increased the longevity of C. elegans compared with OP50. In addition, preconditioning with 3201 enhanced C. elegans immune response against four different foodborne pathogenic bacteria. To uncover the molecular basis of these effects, transcriptome analysis elucidated that 3201 modulates specific gene expression related to the innate immune response in C. elegans. C-type lectin-related genes and lysozyme-related genes, crucial components of the immune system, showed significant upregulation after feeding 3201 compared with OP50. These results suggested that preconditioning with 3201 may enhance the immune response against pathogens. Metabolome analysis revealed increased levels of fumaric acid and succinic acid, metabolites of the citric acid cycle, in C. elegans fed with 3201 compared with OP50. Furthermore, there was an increase in the levels of lactic acid, a well-known antimicrobial compound. This rise in lactic acid levels may have contributed to the robust defense mechanisms against pathogens. In conclusion, this study demonstrated the probiotic properties of the candidate probiotic L. rhamnosus IDCC 3201 by using multi-omics analysis.

Dietary supplementation with Lacticaseibacillus rhamnosus IDCC3201 alleviates sarcopenia by modulating the gut microbiota and metabolites in dexamethasone-induced models.

Probiotics can exert direct or indirect influences on various aspects of health claims by altering the composition of the gut microbiome and producing bioactive metabolites. The aim of this study was to examine the effect of Lacticaseibacillus rhamnosus IDCC3201 on skeletal muscle atrophy in dexamethasone-induced C2C12 cells and a mouse animal model. Dexamethasone treatment significantly reduced C2C12 muscle cell viability, myotube diameter, and levels of muscle atrophic markers (Atrogin-1 and MuRF-1). These effects were alleviated by conditioned media (CM) and cell extract (EX) derived from L. rhamnosus IDCC3201. In addition, we assessed the in vivo therapeutic effect of L. rhamnosus IDCC3201 in a mouse model of dexamethasone (DEX)-induced muscle atrophy. Supplementation with IDCC3201 resulted in significant enhancements in body composition, particularly in lean mass, muscle strength, and myofibril size, in DEX-induced muscle atrophy mice. In comparison to the DEX-treatment group, the normal and DEX + L. rhamnosus IDCC3201 groups showed a higher transcriptional level of myosin heavy chain family genes (MHC1, MHC1b, MHC2A, 2bB, and 2X) and a reduction in atrophic muscle makers. These analyses revealed that L. rhamnosus IDCC3201 supplementation led to increased production of branched-chain amino acids (BCAAs) and improved the Allobaculum genus within the gut microbiota of muscle atrophy-induced groups. Taken together, our findings suggest that L. rhamnosus IDCC3201 represents a promising dietary supplement with the potential to alleviate sarcopenia by modulating the gut microbiome and metabolites.

Molecular characterization and environmental impact of newly isolated lytic phage SLAM_phiST1N3 in the Cornellvirus genus for biocontrol of a multidrug-resistant Salmonella Typhimurium in the swine industry chain.

Salmonella Typhimurium is a highly lethal pathogenic bacterium in weaned piglets, causing significant treatment costs and economic losses in the swine industry. Additionally, due to its ability to induce zoonotic diseases, resulting in harm to humans through the transmission of the pathogen from pork, it presents a serious public health issue. Bacteriophages (phages), viruses that infect specific bacterial strains, have been proposed as an alternative to antibiotics for controlling pathogenic bacteria. In this study, we isolated SLAM_phiST1N3, a phage infecting a multidrug-resistant (MDR) S. Typhimurium wild-type strain isolated from diseased pigs. First, comparative genomics and phylogenetic analysis revealed that SLAM_phiST1N3 belongs to the Cornellvirus genus. Moreover, utilizing a novel classification approach introduced in this study, SLAM_phiST1N3 was classified at the species level. Host range experiments demonstrated that SLAM_phiST1N3 did not infect other pathogenic bacteria or probiotics derived from pigs or other livestock. While complete eradication of Salmonella was not achievable in the liquid inhibition assay, surprisingly, we succeeded in largely eliminating Salmonella in the FIMM analysis, a gut simulation system using weaned piglet feces. Furthermore, using the C. elegans model, we showcased the potential of SLAM_phiST1N3 to prevent S. Typhimurium infection in living organisms. In addition, it was confirmed that bacterial control could be achieved when phage was applied to Salmonella-contaminated pork. pH and temperature stability experiments demonstrated that SLAM_phiST1N3 can endure swine industry processes and digestive conditions. In conclusion, SLAM_phiST1N3 demonstrates potential environmental impact as a substance for Salmonella prevention across various aspects of the swine industry chain.

Pyromeconic acid-enriched Erigeron annuus water extract as a cosmetic ingredient for itch relief and anti-inflammatory activity.

Erigeron annuus (EA), traditionally used to treat disorders such as diabetes and enteritis, contains a variety of chemicals, including caffeic acid, flavonoids, and coumarins, providing antifungal and antioxidative benefits. However, the ingredients of each part of the EA vary widely, and there are few reports on the functionality of water extracts in skin inflammation and barrier protection. We assessed the therapeutic properties of the extract of EA without roots (EEA) and its primary ingredient, pyromeconic acid (PA), focusing on their antihistamine, anti-inflammatory, and antioxidative capabilities using HMC-1(human mast cells) and human keratinocytes (HaCaT cells). Our findings revealed that histamine secretion, which is closely related to itching, was notably reduced in HMC-1 cells following pretreatment with EEA (0.1% and 0.2%) and PA (corresponding concentration, 4.7 of 9.4 µg/mL). Similarly, they led to a marked decrease in the levels of pro-inflammatory cytokines, including IL-1ß, IL-8, IL-6, and IFN-γ. Furthermore, EA and PA enhanced antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT), reduced malondialdehyde (MDA) production, and showed reactive oxygen species (ROS) scavenging activity in HaCaT cells. Moreover, at the molecular level, elevated levels of the pro-inflammatory cytokines IL-1ß, IL-6, TARC, and MDC induced by TNF-α/IFN-γ in HaCaT cells were mitigated by treatment with EEA and PA. We also revealed the protective effects of EEA and PA against SDS-induced skin barrier dysfunction in HaCaT cells by enhancing the expression of barrier-related proteins. Using NanoString technology, a comprehensive analysis of gene expression changes indicated significant modulation of autoimmune and inflammatory genes by EEA and PA. In summary, this study suggests that EEA and the corresponding concentration of PA as an active ingredient have functional cosmetic applications to alleviate itching and improve skin health.

Molecular characterization of Fusarium venenatum-based microbial protein in animal models of obesity using multi-omics analysis.

Microbial protein, produced by fermentation of Fusarium venenatum is a promising candidate alternative protein source. Previous study has demonstrated its ability to improve hyperlipidemia in rats, yet the related mechanism remains unclear. In this study, we aimed to evaluate the potential of F. venenatum as an alternative protein source and its impact on lipid metabolism using multi-omics analysis. Initial experiments with Caenorhabditis elegans revealed that F. venenatum enhanced longevity, improved immune responses, and reduced lipid metabolism by downregulating fat synthesis-related genes. Subsequently, we conducted experiments with mice on a high-fat diet to confirm the anti-obesity effects of F. venenatum. The groups fed F. venenatum showed improved lipid profiles and reduced hepatic fat accumulation. Furthermore, fecal metabolomic analysis showed higher excretion of primary bile acid and cholesterol in the groups fed F. venenatum which might lead to a decrease in lipid digestion and hepatic fat accumulation. Collectively, this series of experiments revealed the potential of F. venenatum as a sustainable alternative protein and its application as an anti-obesity supplement.

Dietary supplementation with probiotics promotes weight loss by reshaping the gut microbiome and energy metabolism in obese dogs.

Obesity and overweight among companion animals are significant concerns, paralleling the issues observed in human populations. Recent research has highlighted the potential benefits of various probiotics in addressing weight-related changes, obesity, and associated pathologies. In this study, we delved into the beneficial probiotic mechanisms in high-fat-induced obese canines, revealing that Enterococcus faecium IDCC 2102 (IDCC 2102) and Bifidobacterium lactis IDCC 4301 (IDCC 4301) have the capacity to mitigate the increase in body weight and lipid accumulation in obese canines subjected to a high-fat diet and hyperlipidemic Caenorhabditis elegans (C. elegans) strain VS29. Both IDCC 2102 and IDCC 4301 demonstrated the ability to reduce systemic inflammation and hormonal disruptions induced by obesity. Notably, these probiotics induced modifications in the microbiota by promoting lactic acid bacteria, including Lactobacillaceae, Ruminococcaceae, and S24-7, with concomitant activation of pyruvate metabolism. IDCC 4301, through the generation of bacterial short-chain fatty acids and carboxylic acids, facilitated glycolysis and contributed to ATP synthesis. Meanwhile, IDCC 2102 produced bacterial metabolites such as acetic acid and butyric acid, exhibiting a particular ability to stimulate dopamine synthesis in a canine model. This stimulation led to the restoration of eating behavior and improvements in glucose and insulin tolerance. In summary, we propose novel probiotics for the treatment of obese animals based on the modifications induced by IDCC 2102 and IDCC 4301. These probiotics enhanced systemic energy utilization in response to high caloric intake, thereby preventing lipid accumulation and restoring stability to the fecal microbiota. Consequently, this intervention resulted in a reduction in systemic inflammation caused by the high-fat diet.IMPORTANCEProbiotic supplementation affected commensal bacterial proliferation, and administering probiotics increased glycolysis and activated pyruvate metabolism in the body, which is related to propanate metabolism as a result of pyruvate metabolism activation boosting bacterial fatty acid production via dopamine and carboxylic acid specialized pathways, hence contributing to increased ATP synthesis and energy metabolism activity.

Protective Effects of Lacticaseibacillus rhamnosus IDCC3201 on Motor Functions and Anxiety Levels in a Chronic Stress Mouse Model.

Growing evidence indicates a crucial role of the gut microbiota in physiological functions. Gut-brain axis imbalance has also been associated with neuropsychiatric and neurodegenerative disorders. Studies have suggested that probiotics regulate the stress response and alleviate mood-related symptoms. In this study, we investigated the effects of the probiotic Lacticaseibacillus rhamnosus IDCC3201 (L3201) on the behavioral response and fecal metabolite content in an unpredictable chronic mild stress (UCMS) mouse model. Our study shows that chronic stress in mice for three weeks resulted in significant changes in behavior, including lower locomotor activity, higher levels of anxiety, and depressive-like symptoms, compared to the control group. Metabolomic analysis demonstrated that disrupted fecal metabolites associated with aminoacyl-tRNA biosynthesis and valine, leucine, and isoleucine biosynthesis by UCMS were restored with the administration of L3201. Oral administration of the L3201 ameliorated the observed changes and improved the behavioral alterations along with fecal metabolites, suggesting that probiotics play a neuroprotective role.

Alleviation of DSS-induced colitis via bovine colostrum-derived extracellular vesicles with microRNA let-7a-5p is mediated by regulating Akkermansia and ß-hydroxybutyrate in gut environments.

IMPORTANCE: Even though studying on the possible involvement of extracellular vesicles (EVs) in host-microbe interactions, how these relationships mediate host physiology has not clarified yet. Our current findings provide insights into the encouraging benefits of dietary source-derived EVs and microRNAs (miRNAs) on organic acid production and ultimately stimulating gut microbiome for human health, suggesting that supplementation of dietary colostrum EVs and miRNAs is a novel preventive strategy for the treatment of inflammatory bowel disease.

Molecular characterization and functionality of rumen-derived extracellular vesicles using a Caenorhabditis elegans animal model.

The rumen fluids contain a wide range of bacteria, protozoa, fungi, and viruses. The various ruminal microorganisms in the rumen provide nutrients by fermenting the forage they eat. During metabolic processes, microorganisms present in the rumen release diverse vesicles during the fermentation process. Therefore, in this study, we confirmed the function of rumen extracellular vesicles (EVs) and their interaction with the host. We confirmed the structure of the rumen EVs by transmission electron microscope (TEM) and the size of the particles using nanoparticle tracking analysis (NTA). Rumen EVs range in size from 100 nm to 400 nm and are composed of microvesicles, microparticles, and ectosomes. Using the Caenorhabditis elegans smart animal model, we verified the interaction between the host and rumen EVs. Exposure of C. elegans to rumen EVs did not significantly enhance longevity, whereas exposure to the pathogenic bacteria Escherichia coli O157:H7 and Staphylococcus aureus significantly increased lifespan. Furthermore, transcriptome analysis showed gene expression alterations in C. elegans exposed to rumen EVs, with significant changes in the metabolic pathway, fatty acid degradation, and biosynthesis of cofactors. Our study describes the effect of rumen EV interactions with the host and provides novel insights for discovering biotherapeutic agents in the animal industry.

Lactobacillus rhamnosus JY02 Ameliorates Sarcopenia by Anti-Atrophic Effects in a Dexamethasone-Induced Cellular and Murine Model.

Sarcopenia is defined as loss of muscle mass and strength due to aging. Recent studies show that sarcopenia may improve via the gut-muscle axis, suggesting that gut health may affect muscle phenotypes. In this study, we aimed to investigate the ability of Lactobacillus rhamnosus JY02 as a probiotic strain isolated from kimchi to alleviate sarcopenia. L. rhamnosus JY02-conditioned medium (CM) reduced dexamethasone (DEX)-induced myotube diameter atrophy and expression of muscle degradation markers (MuRF1 and atrogin-1) in C2C12 cells. The amelioration of sarcopenia was investigated by measuring body composition (lean mass), hand grip strength, myofibril size (using histological analysis), and mRNA and protein expression of muscle-related factors in a DEX-induced mouse model. The results of these analyses showed that L. rhamnosus JY02 supplementation promoted the production of muscle-enhancement markers (MHC Iß, MHC IIα, and Myo-D) and reduced both the production of muscle degradation markers and the symptoms of muscle atrophy (loss of lean mass and muscle strength). We also found decreased levels of pro-inflammatory cytokines (IL-6, IFN- γ) and increased levels of anti-inflammatory cytokines (IL-10) in the serum of DEX+JY02-administered mice compared to those in DEX-treated mice. Overall, these results suggest that L. rhamnosus JY02 is a potent probiotic supplement that prevents sarcopenia by suppressing muscle atrophy.

Molecular characterization of gut microbiome in weaning pigs supplemented with multi-strain probiotics using metagenomic, culturomic, and metabolomic approaches.

BACKGROUND: Probiotics have been reported to exhibit positive effects on host health, including improved intestinal barrier function, preventing pathogenic infection, and promoting nutrient digestion efficiency. These internal changes are reflected to the fecal microbiota composition and, bacterial metabolites production. In accordance, the application of probiotics has been broadened to industrial animals, including swine, which makes people to pursue better knowledge of the correlation between changes in the fecal microbiota and metabolites. Therefore, this study evaluated the effect of multi-strain probiotics (MSP) supplementation to piglets utilizing multiomics analytical approaches including metagenomics, culturomics, and metabolomics. RESULTS: Six-week-old piglets were supplemented with MSP composed of Lactobacillus isolated from the feces of healthy piglets. To examine the effect of MSP supplement, piglets of the same age were selected and divided into two groups; one with MSP supplement (MSP group) and the other one without MSP supplement (Control group). MSP feeding altered the composition of the fecal microbiota, as demonstrated by metagenomics analysis. The abundance of commensal Lactobacillus was increased by 2.39%, while Clostridium was decreased, which revealed the similar pattern to the culturomic approach. Next, we investigated the microbial metabolite profiles, specifically SCFAs using HPLC-MS/MS and others using GC-MS, respectively. MSP supplement elevated the abundance of amino acids, including valine, isoleucine and proline as well as the concentration of acetic acid. According to the correlation analyses, these alterations were found out to be crucial in energy synthesizing metabolism, such as branched-chain amino acid (BCAA) metabolism and coenzyme A biosynthesis. Furthermore, we isolated commensal Lactobacillus strains enriched by MSP supplement, and analyzed the metabolites and evaluated the functional improvement, related to tight junction from intestinal porcine enterocyte cell line (IPEC-J2). CONCLUSIONS: In conclusion, MSP administration to piglets altered their fecal microbiota, by enriching commensal Lactobacillus strains. This change contributed amino acid, acetic acid, and BCAA concentrations to be increased, and energy metabolism pathway was also increased at in vivo and in vitro. These changes produced by MSP supplement suggests the correlation between the various physiological energy metabolism functions induced by health-promoting Lactobacillus and the growth performance of piglets.

Culturomic-, metagenomic-, and transcriptomic-based characterization of commensal lactic acid bacteria isolated from domestic dogs using Caenorhabditis elegans as a model for aging.

In tandem with the fast expansion of the pet-economy industry, the present aging research has been noticing the function of probiotics in extending the healthy lifetime of domestic animals. In this study, we aimed to understand the bacterial compositions of canine feces and isolating lactic acid bacteria (LAB) as commensal LAB as novel potential probiotics for the use of antiaging using Caenorhabditis elegans surrogate animal model. Under an anaerobic, culturomic, and metagenomic analysis, a total of 305 commensal LAB were isolated from diverse domestic dogs, and four strains, Lactobacillus amylolyticus, L. salivarius, Enterococcus hirae, and E. faecium, made prominence as commensal LAB by enhancing C. elegans life span and restored neuronal degeneration induced by aging by upregulating skn-1, ser-7, and odr-3, 7, 10. Importantly, whole transcriptome results and integrative network analysis revealed extensive mRNA encoding protein domains and functional pathways of naturally aging C. elegans were examined and we built the gene informatics basis. Taken together, our findings proposed that a specific gene network corresponding to the pathways differentially expressed during the aging and selected commensal LAB as potential probiotic strains could be provided beneficial effects in the aging of domestic animals by modulating the dynamics of gut microbiota.

In tandem with the fast expansion of the pet-economy industry, the present aging research has been noticing the function of probiotics in extending the healthy lifetime of domestic animals. In this study, collaborating with understanding the characteristics of gut microbiome from canine feces by multiomics approaches including culturomics, metagenomics, and transcriptomics, we isolate and identify commensal lactic acid bacteria (LAB) as novel potential probiotics for the use of antiaging using Caenorhabditis elegans surrogate animal model and multiomics analysis. The selected commensal LAB could be provided beneficial effects in the aging of domestic animals by modulating the dynamics of gut microbiome and applied in the future companion animal market by clarifying their purpose and function.

Postbiotic heat-killed lactobacilli modulates on body weight associated with gut microbiota in a pig model.

For decades, Lactobacillus has been extensively used as beneficial probiotics because it positively effects on the intestinal health of the host and has been studying its possible serve to treat obesity as well as various diseases. This research aimed to investigate the effects of heat-killed Ligilactobacillus salivarius strain 189 (HK LS 189) supplementation on anti-obesity and gut microbiota. A total of 48 pigs were fed either a basal diet or a diet supplemented with HK LS 189 for 4 weeks. The impact of HK LS 189 supplementation on the composition and function of the intestinal microbiota was revealed by 16 S rRNA gene sequencing. HK LS 189 supplementation significantly decreased growth performance. Moreover, HK LS 189 supplementation altered the gut microbiota of the pigs by decreasing the proportion of Prevotella and increasing the proportion of Parabacteroides. Beta-diversity analysis showed a significant difference between the two groups. The results support the potential use of HK LS 189 for its anti-obesity effect in pigs through modulation of the gut microbiota. Furthermore, we found changes in the functional pathways of the gut microbiota. The functional pathway study indicated that metabolism and lipid metabolism differed between the two groups. Our data may contribute to understanding the potential use of postbiotic supplementation with HK LS 189 for improving the anti-obesity effects.

Perspectives on Bovine Milk-Derived Extracellular Vesicles for Therapeutic Applications in Gut Health.

Extracellular vesicles (EVs) are nanosized vesicles secreted from cells into the extracellular environment and are composed of a lipid bilayer that contains cargos with biological activity, such as lipids, proteins, mRNAs, and noncoding microRNAs (miRNAs). Due to their biological activity and their role in cell-to-cell communication, interest in EVs is rapidly increasing. Bovine milk is a food consumed by people of all ages around the world that contains not only a significant amount of nutrients but also EVs. Milk-derived EVs also exhibit biological activity similar to other source-derived EVs, and studies on bovine milk EVs have been conducted in various research fields regarding sufficient milk production. In particular, not only are the effects of milk EVs themselves being studied, but the possibility of using them as drug carriers or biomarkers is also being studied. In this review, the characteristics and cargo of milk EVs are summarized, as well as their uptake and stability, efficacy and biological effects as carriers, and future research directions are presented.

Enhanced γ-aminobutyric acid and sialic acid in fermented deer antler velvet and immune promoting effects.

Deer antler velvet is widely used in traditional medicine for its anti-aging, antioxidant, and immunity-enhancing effects. However, few studies have reported on the discovery of probiotic strains for deer antler fermentation to increase functional ingredient absorption. This study evaluated the ability of probiotic lactic acid bacteria to enhance the concentrations of bioactive molecules (e.g., sialic acid and gamma-aminobutyric acid [GABA]) in extracts of deer antler velvet. Seventeen strains of Lactobacillus spp. that were isolated from kimchi and infant feces, including L. sakei, L. rhamnosus, L. brevis, and L. plantarum, and those that improved the life span of Caenorhabditis elegans were selected for evaluation. Of the 17 strains, 2 (L. rhamnosus LFR20-004 and L. sakei LFR20-007) were selected based on data showing that these strains increased both the sialic acid and GABA contents of deer antler extract after fermentation for 2 d and significantly improved the life span of C. elegans. Co-fermentation with both strains further increased the concentrations of sialic acid, GABA, and metabolites such as short-chain fatty acids and amino acids. We evaluated the biological effects of the fermented antler velvet (FAV) on the antibacterial immune response in C. elegans by assessing worm survival after pathogen infection. The survival of the C. elegans conditioned with FAV for 24 h was significantly higher compared with that of the control worm group fed only normal feed (non-pathogenic E. coli OP50) exposed to E. coli O157:H7, Salmonella typhi, and Listeria monocytogenes. To evaluate the protective effects of FAV on immune response, cyclophosphamide (Cy), an immune-suppressing agent was treated to in vitro and in vivo. We found that FAV significantly restored viability of mice splenocytes and immune promoting-related cytokines (interleukin [IL]-6, IL-10, inducible nitric oxide synthase [iNOS], interferon [IFN]-γ, and tumor necrosis factor [TNF]-α) were activated compared to non-fermented deer antlers. This finding indicated the protective effect of FAV against Cy-induced cell death and immunosuppressed mice. Taken together, our study suggests that immune-promoting antler velvet can be produced through fermentation using L. rhamnosus LFR20-004 and L. sakei LFR20-007.

Decoding the intestinal microbiota repertoire of sow and weaned pigs using culturomic and metagenomic approaches.

To elucidate the role and mechanism of microbes, we combined culture-dependent and culture-independent approaches to investigate differences in gut bacterial composition between sows and weaned pigs. Under anaerobic conditions, several nonselective and selective media were used for isolation from fecal samples. All isolated bacteria were identified and classified through 16S rRNA sequencing, and the microbiota composition of the fecal samples was analyzed by metagenomics using next generation sequencing (NGS) technology. A total of 278 and 149 colonies were acquired from the sow and weaned pig fecal samples, respectively. Culturomics analysis revealed that diverse bacterial genus and species belonged to Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes were isolated from sow and weaned pigs. When comparing culture-dependent and culture-independent analyses, 191 bacterial species and 2 archaeal bacterial species were detected through culture-independent analysis, and a total of 23 bacteria were isolated through a culture-dependent approach, of which 65% were not detected by metagenomics. In conclusion, culturomics and metagenomics should be properly combined to fully understand the intestinal microbiota, and livestock-derived microbial resources should be informed by culturomic approaches to understand and utilize the mechanism of host-microbe interactions.

Bacillus amyloliquefaciens SCGB1 Alleviates Dextran Sulfate Sodium-Induced Colitis in Mice Through Immune Regulation.

Probiotics, as living microorganisms, exert health benefits to the host by alleviating excess inflammation through modulating the immune system and establishing intestinal homeostasis. In this study, we evaluated the probiotic characteristics and inflammation alleviatory effects of Bacillus amyloliquefaciens isolated from traditional Korean fermented foods. The strains withstood the acidic environment of the digestive process, extended the lifespan of Caenorhabditis elegans, and enhanced pmk-1 expression. However, only B. amyloliquefaciens SCGB1 could attach to C. elegans in the intestines, which enhanced their survival upon exposure to Escherichia coli O157:H7. We also investigated the anti-inflammatory effect of SCGB1 using the RAW264.7 macrophage stimulated with lipopolysaccharide. The strain treatment enhanced anti-inflammatory cytokine interleukin (IL)-10 secretion and downregulated proinflammatory cytokine IL-6 expression in vitro. Next, we used a dextran sulfate sodium (DSS)-induced colitis mouse model to investigate whether SCGB1 can ameliorate gut inflammation in vivo. Compared to those in the DSS-induced mice, histological damage and IL-6 cytokine levels were significantly reduced in SCGB1-fed mice. These results suggest that B. amyloliquefaciens SCGB1 as potential probiotics may have health-promoting effects by reduction of inflammatory responses.

Comparative analysis of dietary exosome-derived microRNAs from human, bovine and caprine colostrum and mature milk.

Mammalian milk including microRNAs (miRNAs) as a novel class of noncoding RNAs, that can be transferred to infants and it plays on a critical role in biological functions such as immune regulation and development. However, the origin and functional importance of milk-derived miRNAs are still undetermined. This study applied RNA sequencing to explore the featured profiles of miRNA expression in colostrum and mature milk-originated exosomes from human, bovine, and caprine milk. These dietary exosome-derived miRNAs are highly conserved in human, bovine and caprine milk. Interestingly, abundant miRNAs expressed in human milk are similarly conserved across species. In addition, we confirmed that immune-related miRNAs (miR-30a-5p, miR-22-3p, and miR-26a) are commonly observed in the colostrum and mature milk of cows and caprines as well as humans. Our results provide new insights and resources for investigating the functionality of immune-associated miRNAs and evaluating physiological and biological condition in human, bovine and caprine milk as biomarkers.

Bacterial Quality, Prevalence of Pathogens, and Molecular Characterization of Biofilm-Producing Staphylococcus aureus from Korean Dairy Farm Environments.

Raw milk acts as a mediator of major foodborne pathogenic bacterial infections. However, the sources of pathogens that contaminate milk are often unclear. This study assessed the prevalence of sanitary quality-indicating bacteria (total aerobic bacteria, psychrotrophic bacteria, coliform, and yeast/molds), including seven foodborne pathogens, in a dairy farm environment and processing plant in Korea. The microbiological analysis showed that a few sites, such as vat bottoms, room floors, drain holes, and niches, showed high microbial loads in most dairy farms. Based on quantitative microbial tests, Bacillus cereus was detected in three farms and Staphylococcus aureus was detected in only one farm. Among them, S. aureus JDFM SA01 isolated from a milk filter showed strong biofilm formation and toxicity to the host Caenorhabditis elegans. Subsequently, RNA-seq was performed to characterize the biofilm formation ability of S. aureus JDFM SA01. In biofilms, the significant upregulation of genes encoding microbial surface components and recognizing adhesive matrix molecules promotes adhesion might explain the increased viability and biomass of biofilms. This study provided insight into the prevalence of pathogenic bacteria and microbial contamination levels across dairy farms.

Evaluation of Probiotic Characteristics of Newly Isolated Lactic Acid Bacteria from Dry-Aged Hanwoo Beef.

Dry aging is a traditional method that improves meat quality, and diverse microbial communities are changed during the process. Lactic acid bacteria (LAB) are widely present in fermented foods and has many beneficial effects, such as immune enhancement and maintenance of intestinal homeostasis. In this study, we conducted metagenomic analysis to evaluate the changes in the microbial composition of dry-aged beef. We found that lactic acid bacterial strains were abundant in dry-aged beef including Lactobacillus sakei and Enterococcus faecalis. We investigated their abilities in acid and bile tolerance, adhesion to the host, antibiotic resistance, and antimicrobial activity as potential probiotics, confirming that L. sakei and E. faecalis strains had remarkable capability as probiotics. The isolates from dry-aged beef showed at least 70% survival under acidic conditions in addition to an increase in the survival level under bile conditions. Antibiotic susceptibility and antibacterial activity assays further verified their effectiveness in inhibiting all pathogenic bacteria tested, and most of them had low resistance to antibiotics. Finally, we used the Caenorhabditis elegans model to confirm their life extension and influence on host resistance. In the model system, 12D26 and 20D48 strains had great abilities to extend the nematode lifespan and to improve host resistance, respectively. These results suggest the potential use of newly isolated LAB strains from dry-aged beef as probiotic candidates for production of fermented meat.