Lactobacillus sakei K040706 evokes immunostimulatory effects on macrophages through TLR 2-mediated activation

Multi-omics insights into anti-colitis benefits of the synbiotic and postbiotic derived from wheat bran arabinoxylan and Limosilactobacillus reuteri

Exploring nutritional therapies that manipulate tryptophan metabolism to activate AhR signaling represents a promising approach for mitigating chronic colitis. Arabinoxylan is a bioactive constituent abundant in wheat bran. Here, we comprehensively investigated anti-colitis potentials of wheat bran arabinoxylan (WBAX), its synbiotic and postbiotic derived from WBAX and Limosilactobacillus reuteri WX-94 (i.e., a probiotic strain exhibiting tryptophan metabolic activity). WBAX fueled L. reuteri and promoted microbial conversion of tryptophan to AhR ligands during in vitro fermentation in the culture medium and in the fecal microbiota from type 2 diabetes. The WBAX postbiotic outperformed WBAX and its synbiotic in augmenting efficacy of tryptophan in restoring DSS-disturbed serum immune markers, colonic tight junction proteins and gene profiles involved in amino acid metabolism and FoxO signaling. The WBAX postbiotic remodeled gut microbiota and superiorly enhanced AhR ligands (i.e., indole metabolites and bile acids), alongside with elevation in colonic AhR and IL-22. Associations between genera and metabolites modified by the postbiotic and colitis in human were verified and strong binding capacities between metabolites and colitis-related targets were demonstrated by molecular docking. Our study advances the novel perspective of WBAX in manipulating tryptophan metabolism and anti-colitis potentials of WBAX postbiotic via promoting gut microbiota-dependent AhR signaling.

Intraspecific difference of Latilactobacillus sakei in inflammatory bowel diseases: Insights into potential mechanisms through comparative genomics and metabolomics analyses

Inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of the gastrointestinal tract that have become a global health burden. Studies have revealed that Latilactobacillus sakei can effectively alleviate various immune diseases, including colitis, rheumatoid arthritis, and metabolic disorders. Here, we obtained 72 strains of L. sakei from 120 fermentation and fecal samples across China. In total, 16 strains from different sources were initially screened in an in vitro Caco-2 model induced by dextran sulfate sodium. Subsequently, six strains (four exhibiting effectiveness and two exhibiting ineffectiveness) were selected for further validation in an in vivo colitis mouse model. The results demonstrated that L. sakei strains exhibited varying degrees of amelioration of the colitis disease process. Notably, L. sakei CCFM1267, the most effective strain, significantly restored colon length and tight-junction protein expression, and reduced the levels of cytokines and associated inflammatory enzymes. Moreover, L. sakei CCFM1267 upregulated the abundance of Enterorhabdus, Alloprevotella, and Roseburia, leading to increased levels of acetic acid and propionic acid. Conversely, the other four strains (L. sakei QJSSZ1L4, QJSSZ4L10, QGZZYRHMT1L6, and QGZZYRHMT2L6) only exhibited a partial remission effect, while L. sakei QJSNT1L10 displayed minimal impact. Therefore, L. sakei CCFM1267 and QJSNT1L10 were selected for further exploration of the mechanisms underlying their differential mitigating effects. Comparative genomics analysis revealed significant variations between the two strains, particularly in genes associated with carbohydrate-active enzymes, such as the glycoside hydrolase family, which potentially contribute to the diverse profiles of short-chain fatty acids in vivo. Additionally, metabolome analysis demonstrated that acetylcholine and indole-3-acetic acid were the main differentiating metabolites of the two strains. Therefore, the strains of L. sakei exhibited varying degrees of effectiveness in alleviating IBD-related symptoms, and the possible reasons for these variations were attributed to discrepancies in the carbohydrate-active enzymes and metabolites among the strains.

Probiotic activity of ropy Lactiplantibacillus plantarum NA isolated from Chinese northeast sauerkraut and comparative evaluation of its live and heat-killed cells on antioxidant activity and RAW 264.7 macrophage stimulation

Lactic acid bacteria are known to have a positive impact on health and considered as functional supplements and additives. This study aimed to evaluate the probiotic properties of ropy Latilactobacillus isolated from Chinese northeast sauerkraut and to determine the antioxidant and immunoregulatory activities of its heat-killed cells compared to its live strains to assess its functional activity. After the analysis of the 16r DNA and phylogenetic tree, it was identified as a Lactiplantibacillus plantarum and named L. plantarum NA. L. plantarum NA was resistant to simulated gastrointestinal conditions in vitro. In addition, L. plantarum NA exhibited cholesterol degradation, antibiotic susceptibility, and antibacterial activity. Heat-killed L. plantarum NA exhibited antioxidant and immune-stimulating activities similar to live cells, which may be associated with the undamaged overall structure after heating. The results of antioxidant activity analysis suggested that both live and heat-killed L. plantarum NA possessed capacity for scavenging free radicals, including 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydroxyl radicals and superoxide radicals. The ABTS scavenging activity of heat-killed cells (38%) was significantly higher than that of viable (19%) L. plantarum NA. Furthermore, RAW 264.7 macrophages treated with L. plantarum NA induced the production of nitric oxide, cytokines (IL-6 and TNF-α), and reactive oxygen species (ROS). The NO/iNOS signaling pathway could be activated by L. plantarum NA and promoted NO production. Both live and heat-killed cells had a potential impact on the immunomodulatory activity, with different dosages. These results suggest that the novel L. plantarum NA isolated from Chinese northeast sauerkraut could be useful as a probiotic strain and applied to functional food processing and pharmaceutical fields as a potential immunomodulator.

Exploring the Phosphatidylcholine in Inflammatory Bowel Disease: Potential Mechanisms and Therapeutic Interventions

BACKGROUND

Inflammatory bowel disease (IBD) is a significant health problem with an increasing financial burden worldwide. Although various treatment strategies have been used, the results were not satisfactory. More and more researches have proved that the application of phosphatidylcholine (PC) may become an alternative therapy for IBD.

OBJECTIVE

This review aims to provide an overview of the possible mechanisms of PC and promote the potential application of PC for IBD therapy further.

METHODS

A comprehensive literature search was performed in PubMed with the following keywords: 'phosphatidylcholine', 'inflammatory bowel disease', 'Crohn's disease', 'inflammation', 'ulcerative colitis', 'therapy', 'nanomedicines', 'PKCζ', 'lysophosphatidylcholine', 'microbiota' and 'drug carrier'. The logical operators "AND" and "OR" were applied to combine different sets of the search results.

RESULTS

Studies suggested that PC displays a significant effect in the treatment of IBD by modulating gut barrier function, remodeling gut microbiota structure, regulating polarization of macrophages, and reducing the inflammatory response. PC has also been exploited as a drug carrier for anticancer or anti-inflammation agents in multiple forms, which implies that PC has immense potential for IBD therapy.

CONCLUSION

PC has shown promising potential as a new therapeutic agent or a drug carrier, with a novel, stable, prolonged mechanism of action in treating IBD. However, more high-quality basic and clinical studies are needed to confirm this.

Immunostimulatory Activity of Cordyceps militaris Fermented with Pediococcus pentosaceus SC11 Isolated from a Salted Small Octopus in Cyclophosphamide-Induced Immunocompromised Mice and Its Inhibitory Activity against SARS-CoV 3CL Protease

In this study, we investigated the immune-enhancing and anti-viral effects of germinated Rhynchosia nulubilis (GRC) fermented with Pediococcus pentosaceus SC11 (GRC-SC11) isolated from a salted small octopus. The cordycepin, β-glucan, and total flavonoid contents increased in GRC after SC11 fermentation. GRC-SC11 inhibits 3CL protease activity in severe acute respiratory syndrome-associated coronavirus (SARS-CoV). GRC-SC11 significantly increased thymus and spleen indices in immunocompromised mice. The rate of splenocyte proliferation was higher in GRC-SC11-treated immunocompromised mice than that in GRC-treated immunocompromised mice in the presence or absence of concanavalin A. In addition, GRC-SC11 increased the phagocytic activity and nitric oxide production in immunocompromised mice. The mRNA expression of interferon-gamma (IFN-γ), interferon-alpha (IFN-α), and interferon-stimulated gene 15 (ISG15) was up-regulated in GRC-SC11 treated RAW 264.7 macrophages, compared to GRC. Our study indicates that GRC-SC11 might be a potential therapeutic agent for immunocompromised patients who are vulnerable to SARS-CoV infection.

Immunostimulatory Activity of Lactic Acid Bacteria Cell-Free Supernatants through the Activation of NF-κB and MAPK Signaling Pathways in RAW 264.7 Cells

Lactic acid bacteria (LAB) can improve host health and has strong potential for use as a health functional food. Specific strains of LAB have been reported to exert immunostimulatory effects. The primary goal of this study was to evaluate the immunostimulatory activities of novel LAB strains isolated from humans and foods and to investigate the probiotic properties of these strains. Cell-free supernatants (CFS) obtained from selected LAB strains significantly increased phagocytosis and level of nitric oxide (NO) and pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 in RAW264.7 macrophage cells. The protein expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, which are immunomodulators, was also upregulated by CFS treatment. CFS markedly induced the phosphorylation of nuclear factor-κB (NF-κB) and MAPKs (ERK, JNK, and p38). In addition, the safety of the LAB strains used in this study was demonstrated by hemolysis and antibiotic resistance tests. Their stability was confirmed under simulated gastrointestinal conditions. Taken together, these results indicate that the LAB strains selected in this study could be useful as probiotic candidates with immune-stimulating activity.

Immunostimulatory effects of dairy probiotic strains Bifidobacterium animalis ssp. lactis HY8002 and Lactobacillus plantarum HY7717

Previous studies reported that Bifidobacterium animalis ssp. lactis HY8002 (HY8002) improved intestinal integrity and had immunomodulatory effects. Lactobacillus plantarum HY7717 (HY7717) was screened in vitro from among 21 other lactic acid bacteria (LAB) and demonstrated nitric oxide (NO) production. The aims of this study were to investigate the individual and combined ex vivo and in vivo effects of LAB strains HY8002 and HY7717 at immunostimulating mice that have been challenged with an immunosuppressant drug. The combination of HY8002 and HY7717 increased the secretion of cytokines such as interferon (IFN)-γ, interleukin (IL)-12, and tumor necrosis factor (TNF)-α in splenocytes. In a cyclophosphamide (CTX)-induced immunosuppression model, administration of the foregoing LAB combination improved the splenic and hematological indices, activated natural killer (NK) cells, and up-regulated plasma immunoglobulins and cytokines. Moreover, this combination treatment increased Toll-like receptor 2 (TLR2) expression. The ability of the combination treatment to upregulate IFN-γ and TNF-α in the splenocytes was inhibited by anti-TLR2 antibody. Hence, the immune responses stimulated by the combination of HY8002 and HY7717 are associated with TLR2 activation. The preceding findings suggest that the combination of the HY8002 and HY7717 LAB strains could prove to be a beneficial and efficacious immunostimulant probiotic supplement. The combination of the two probiotic strains will be applied on the dairy foods including yogurt and cheese.

Fermented food: Should patients with cardiometabolic diseases go back to an early neolithic diet?

Fermentation has been used since the Early Neolithic period to preserve foods. It has inherent organoleptic and nutritive properties that bestow health benefits, including reducing inflammation and oxidative stress, supporting the growth of salutogenic microbiota, enhancing intestinal mucosal protection and promoting beneficial immunometabolic health effects. The fermentation of food with specific microbiota increases the production salutogenic bioactive compounds that can activate Nrf2 mediated cytoprotective responses and mitigate the effects of the 'diseasome of aging' and its associated inflammageing, which presents as a prominent feature of obesity, type-2 diabetes, cardiovascular and chronic kidney disease. This review discusses the importance of fermented food in improving health span, with special reference to cardiometabolic diseases.

SYNERGISTIC IMMUNOMODULATORY ACTIVITY OF PROBIOTICS BIFIDOBACTERIUM ANIMALIS AND LACTOBACILLUS CASEI IN ENTEROAGGREGATIVE ESCHERICHIA COLI (EAEC)-INFECTED CACO-2 CELLS

BACKGROUND

Enteroaggregative Escherichia coli (EAEC) is an E. coli pathotype that presents aggregative adhesion patterns on in vitro cultivated cells, mainly related to persistent diarrhea cases in children. EAEC virulence factors are important for host colonization and pathogeni-city. Intestinal epithelial cells (IECs) recognize pathogen-associated molecular patterns (PAMPs) and initiate an immune response. Several studies using in vivo and in vitro models emphasize the probiotic activity and immunomodulatory capacity of Lactobacillus and Bifidobacterium species.

OBJECTIVE

To evaluate the modulation of cytokine production by probiotics Bifidobacterium animalis and Lactobacillus casei in human intestinal Caco-2 cells exposed to different strains of EAEC.

METHODS

Caco-2 cells were incubated with EAEC strains in the presence or absence of probiotics. The production of cytokines IL-8, TNF-α, IL-1β and IL-10 was evaluated in the supernatants by a sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

Cytokine production did not change when uninfected and EAEC-infected Caco-2 cells were exposed to probiotics separately. All EAEC induced a significant increase in IL-8 production by Caco-2 cells, but the probiotics, even together, could not reduce its production. On the other hand, the synergic activity of probiotic strains significantly increased TNF-α production but decreased the basal production of IL-1ß. Also, probiotics induced a significant increase in the production of the anti-inflammatory cytokine IL-10 during EAEC infection.

CONCLUSION

Our results reinforce the synergistic immunomodulatory activity of probiotics during EAEC infection.

Strain-Specific Identification and In Vivo Immunomodulatory Activity of Heat-Killed Latilactobacillus sakei K040706

We previously reported that the immunostimulatory activity of heat-killed Latilactobacillus sakei K040706 in macrophages and cyclophosphamide (CTX)-treated mice. However, identification of heat-killed L. sakei K040706 (heat-killed LS06) using a validated method is not yet reported. Further, the underlying molecular mechanisms for its immunostimulatory effects in CTX-induced immunosuppressed mice remain unknown. In this study, we developed strain-specific genetic markers to detect heat-killed L. sakei LS06. The lower detection limit of the validated primer set was 2.1 × 10⁵ colony forming units (CFU)/mL for the heat-killed LS06 assay. Moreover, oral administration of heat-killed LS06 (10⁸ or 10⁹ CFU/day, p.o.) effectively improved the body loss, thymus index, natural killer cell activity, granzyme B production, and T and B cell proliferation in CTX-treated mice. In addition, heat-killed LS06 enhanced CTX-reduced immune-related cytokine (interferon-γ, interleukin (IL)-2, and IL-12) production and mRNA expression. Heat-killed LS06 also recovered CTX-altered microbiota composition, including the phylum levels of Bacteroidetes, Firmicutes, and Proteobacteria and the family levels of Muribaculaceae, Prevotellaceae, Tannerellaceae, Christensenellaceae, Gracilibacteraceae, and Hungateiclostridiaceae. In conclusion, since heat-killed L. sakei K040706 ameliorated CTX-induced immunosuppression and modulated gut microbiota composition, they have the potential to be used in functional foods for immune regulation.

Antioxidant Effect of Lactobacillus fermentum CQPC04-Fermented Soy Milk on D-Galactose-Induced Oxidative Aging Mice

The aim of this study is to evaluate the changes in soy isoflavones and peptides in soy milk after lactic acid bacterial fermentation, and explore the positive effects of fermented soy milk on an oxidative aging mouse model induced with D-galactose. We found that free soybean isoflavones and peptides increased after soy milk was fermented by Lactobacillus fermentum CQPC04. The in vivo results indicated that L. fermentum CQPC04-fermented soy milk enhanced the organ index of the liver and spleen, and improved the pathological morphology of the liver, spleen, and skin. L. fermentum CQPC04-fermented soy milk increased the enzymatic activity of glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), and catalase (CAT), increased glutathione (GSH), but decreased the levels of nitric oxide (NO) and malondialdehyde (MDA) in serum, liver, and brain tissues of oxidative aging mice. The above mentioned fermented soy milk also increased the levels of collagen I (Col I), hyaluronic acid (HA), and collagen III (Col III), and decreased the levels of advanced glycation End products (AGEs) and hydrogen peroxide (H₂O₂). The RT-qPCR results showed that L. fermentum CQPC04-fermented soy milk upregulated the mRNA expression of nuclear factor erythroid 2?related factor (Nrf2), heme oxygenase-1 (HMOX1), quinone oxido-reductase 1 (Nqo1), neuronal nitric oxide synthase (NOS1), endothelial nitric oxide synthase (NOS3), Cu/Zn–superoxide dismutase (Cu/Zn-SOD), Mn–superoxide dismutase (Mn-SOD), and CAT, but downregulated the expression of inducible nitric oxide synthase (NOS2) and glutamate cysteine ligase modifier subunit (Gclm) in liver and spleen tissues. Lastly, the fermented soy milk also increased the gene expression of Cu/Zn-SOD, Mn-SOD, CAT, GSH-Px, matrix metalloproteinases 1 (TIMP1), and matrix metalloproteinases 2 (TIMP2), and decreased the expression of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) in skin tissue. In conclusion, L. fermentum CQPC04-fermented soy milk was able to satisfactorily delay oxidative aging effects, and its mechanism may be related to the increase in free soy isoflavones and peptides.

Integrated Phenotypic-Genotypic Analysis of Latilactobacillus sakei from Different Niches

Increasing attention has been paid to the potential probiotic effects of Latilactobacillus sakei. To explore the genetic diversity of L. sakei, 14 strains isolated from different niches (feces, fermented kimchi, and meat products) and 54 published strains were compared and analyzed. The results showed that the average genome size and GC content of L. sakei were 1.98 Mb and 41.22%, respectively. Its core genome mainly encodes translation and transcription, amino acid synthesis, glucose metabolism, and defense functions. L. sakei has open pan-genomic characteristics, and its pan-gene curve shows an upward trend. The genetic diversity of L. sakei is mainly reflected in carbohydrate utilization, antibiotic tolerance, and immune/competition-related factors, such as clustering regular interval short palindromic repeat sequence (CRISPR)-Cas. The CRISPR system is mainly IIA type, and a few are IIC types. This work provides a basis for the study of this species.

Lactobacillus sakei Pro-Bio65 Reduces TNF-α Expression and Upregulates GSH Content and Antioxidant Enzymatic Activities in Human Conjunctival Cells

Purpose

The study investigates the regulatory effects exhibited by lysate of Lactobacillus sakei pro-Bio65 (4%; L.SK) on the human conjunctival epithelial (HCE) cell line.

Methods

Trypan blue and methylthiazol tetrazolium (MTT) methods were used to assess cell growth and viability. Mitochondrial membrane potential was assessed by JC-1 staining and cytofluorimetric detection methods. The antioxidant pattern and the intracellular reactive oxygen species (ROS) levels were analyzed by spectrophotometric and spectrofluorimetric methods. NF-κB luciferase activity was quantified by luminometric detection. NF-κB nuclear translocation, as well as mitochondrial morphology, were investigated by immunofluorescence using confocal microscopy. Cytokines and COX2 expression levels were determined by Western blot analyses.

Results

This study demonstrates that L.SK exposure does not influence HCE cell proliferation and viability in vitro. L.SK paraprobiotic induces mild-low levels of intracellular ROS. It is coupled to changes in the mitochondrial membrane potential (ΔΨm), in a context of a regular mitochondrial-network organization. The negative modulation of tumor necrosis factor alpha (TNF-α) expression levels and rising antioxidant defense efficiency, mediated by the upregulation of glutathione (GSH) and increased antioxidant enzymatic activities, were observed.

Conclusions

This study demonstrates that L.SK empowers the antioxidant endogenous efficiency of HCE cells, by the upregulation of the GSH content and the enzymatic antioxidant pattern, and concurrently reduces TNF-α protein expression.

Translational Relevance

Although the obtained in vitro results should be confirmed by in vivo investigations, our data suggest the possibility of L.SK paraprobiotic application for promoting eye health, exploring its use as an endogen antioxidant system inducer in preventing and treating different oxidative stress-based, inflammatory, and age-related conditions.

Protective effect of exopolysaccharide fraction from Bacillus subtilis against dextran sulfate sodium-induced colitis through maintenance of intestinal barrier and suppression of inflammatory responses

We previously reported that an exopolysaccharide-enriched fraction from Bacillus subtilis J92 (B-EPS) could improve immune functions by regulating the immunological parameters of IFN-γ-primed macrophages, CD3/CD28-stimulated splenocytes, and in cyclophosphamide-induced immunosuppressed mice. In the present study, we investigated whether B-EPS contributes to the maintenance of intestinal barrier integrity in a dextran sodium sulfate (DSS)-induced colitis mouse model that mimics human inflammatory bowel disease (IBD). B-EPS treatment improved histological characteristics and common features including a high disease activity index (DAI), an increased spleen weight, and colon shortening in DSS-induced colitis. B-EPS also effectively restored intestinal barrier function by modulating tight junction-related proteins (claudin-1, claudin-2, and occludin) and epithelial-mesenchymal transition (EMT) marker proteins (E-cadherin, N-cadherin, and vimentin). Moreover, B-EPS downregulated immune cell infiltration and inflammatory responses including the production of inflammatory cytokines, such as IL-6 and IL-1β, and activation of nuclear factor-kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3). Taken together, these results suggest that B-EPS could serve as a functional food ingredient for improving intestinal barrier function and alleviating colonic inflammation in IBD.

Colonization and immunoregulation of Lactobacillus plantarum BF_15, a novel probiotic strain from the feces of breast-fed infants

Immunosuppression is a manifestation imbalance in the immune system, often during unhealthy states. In recent years, lactic acid bacteria (LAB) have been found to be important components of the body's innate immune system, and indispensable to maintaining normal immune function. Lactobacillus plantarum BF_15, a novel strain isolated from the feces of breast-fed infants, which has shown potential as an immunomodulator in vitro. In the present study, with the Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) based on RNA-polymerase beta subunit encoding gene (rpoB) to analyze the colonization of L. plantarum BF_15 in the intestine of mice. In addition, Lactobacillus rhamnosus GG (LGG) as a positive control strain, by measuring immune-related indexes and the diversity of intestinal microbiota, the effects of BF_15 on immunoregulation and intestinal microbiota dysbiosis were investigated to elucidate whether the attenuation of immunosuppression is related to the modulation of intestinal microbiota. Results did indeed support this notion that BF_15 did colonize murine intestines well, in which it could still be detected in mice feces 14 days after stopping the probiotic administration. Moreover, BF_15 found to protect mice against reduction in the levels of several immune-related indicators, including the thymus and spleen indexes, splenic lymphocyte proliferation, toe swelling degree, serum hemolysin-antibody level, and macrophage phagocytosis index, triggered by high-dose (200 mg kg-1) intraperitoneal administration of cyclophosphamide (CTX). In addition, the strain was also found to effectively balance intestinal microbiota dysbiosis in the mice. Collectively, these results indicated that L. plantarum BF_15 can not only successfully colonize murine intestines, but also can effectively alleviate CTX-induced immunosuppression, once established, by rebalancing the intestinal microbiota. This, therefore, provides strong evidence for the view that BF_15 has the potential to become a highly effective immunomodulating probiotic in human microbiota as well.

Harnessing the potential of Lactobacillus species for therapeutic delivery at the lumenal-mucosal interface

Lactobacillus species have been studied for over 30 years in their role as commensal organisms in the human gut. Recently there has been a surge of interest in their abilities to natively and recombinantly stimulate immune activities, and studies have identified strains and novel molecules that convey particular advantages for applications as both immune adjuvants and immunomodulators. In this review, we discuss the recent advances in Lactobacillus-related activity at the gut/microbiota interface, the efforts to probe the boundaries of the direct and indirect therapeutic potential of these bacteria, and highlight the continued interest in harnessing the native capacity for the production of biogenic compounds shown to influence nervous system activity. Taken together, these aspects underscore Lactobacillus species as versatile therapeutic delivery vehicles capable of effector production at the lumenal-mucosal interface, and further establish a foundation of efficacy upon which future engineered strains can expand.

The immune-enhancing effect of anthocyanin-fucoidan nanocomplex in RAW264.7 macrophages and cyclophosphamide-induced immunosuppressed mice

Aronia, a healthy fruit well known as black chokeberry, has health-promoting effects on hypertension, oxidative stress, and diabetes. Despite many reports of bioactivities of aronia, there is little scientific research on the potential for immune-enhancement. So, anthocyanin-fucoidan nanocomplex (AFNC, a nanocomplex of aronia extract and fucoidan) has been developed to improve immune-enhancement. This study aimed to identify immunomodulatory effects and underlying mechanisms of AFNC using RAW264.7 macrophages and cyclophosphamide-induced immunosuppressed mice. As a result, AFNC-treated RAW264.7 macrophages elevated the production of IL-2, IL-6, tumor necrosis factor (TNF)-α, and nitric oxide (NO). AFNC-enhanced inducible NO synthase expression via nuclear factor-κB signaling pathways. AFNC dose-dependently increased levels of IL-2, IL-6, TNF-α, IL-10, IL-12, interferon-γ, or IL-4 in the serum and spleen of immunosuppressed mice. Taken together, AFNC encourages the immune-enhancing activity through immunostimulatory cytokine production by activation of macrophage. Therefore, these results suggest that AFNC is useful for immunodeficiency-related disorders. PRACTICAL APPLICATIONS: In these days of prevalence of infectious diseases, individual immunity is very important. AFNC has the immune-enhancing effects through immunostimulatory cytokine production by activation of macrophage. Therefore, AFNC could be widely applied to ameliorate a variety of diseases caused by immunosuppression such as infectious diseases.

The Complete Genome of Probiotic Lactobacillus sakei Derived from Plateau Yak Feces

Probiotic bacteria are receiving increased attention due to the potential benefits to their hosts. Plateau yaks have resistance against diseases and stress, which is potentially related to their inner probiotics. To uncover the potential functional genes of yak probiotics, we sequenced the whole genome of Lactobacillus sakei (L. sakei). The results showed that the genome length of L. sakei was 1.99 Mbp, with 1943 protein coding genes (21 rRNA, 65 tRNA, and 1 tmRNA). There were three plasmids found in this bacteria, with 88 protein coding genes. EggNOG annotation uncovered that the L. sakei genes were found to belong to J (translation, ribosomal structure, and biogenesis), L (replication, recombination, and repair), G (carbohydrate transport and metabolism), and K (transcription). GO annotation showed that most of the L. sakei genes were related to cellular processes, metabolic processes, biological regulation, localization, response to stimulus, and organization or biogenesis of cellular components. CAZy annotation found that there were 123 CAZys in the L. sakei genome, with glycosyl transferases and glycoside hydrolases. Our results revealed the genome characteristics of L. sakei, which may give insight into the future employment of this probiotic bacterium for its functional benefits.

Immunostimulatory Effects of Live Lactobacillus sakei K040706 on the CYP-Induced Immunosuppression Mouse Model

Our previous studies have shown that heat-killed Lactobacillus sakei K040706 exerts immunostimulatory and anti-inflammatory activities in macrophages, cyclophosphamide (CYP)-treated mice, and dextran sulfate sodium–induced colitis mice. However, the immunostimulatory effects of live Lactobacillus sakei K040706 (live K040706) against CYP-induced immunosuppression and its underlying molecular mechanisms remain unknown. Therefore, we investigated the immunostimulatory effects of live K040706 (10⁸ or 10⁹ colony forming unit (CFU)/day, p.o.) in CYP-induced immunosuppressed mice. Oral administration of live K040706 prevented the CYP-induced decreases in body weight, thymus index, natural killer (NK) cell activity, T and B cell proliferation, and cytokine (interferon (IFN)-γ, interleukin (IL)-2, and IL-12) production. The administration of live K040706 also exerted positive effects on the gut microbiota of CYP-induced mice, resulting in a microbiota composition similar to that of normal mice. Moreover, live K040706 significantly enhanced IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) production in the splenocytes and Peyer’s patch (PP) cells of mice and increased bone marrow (BM) cell proliferation. Taken together, our data indicate that live K040706 may effectively accelerate recovery from CYP-induced immunosuppression, leading to activation of the immune system. Therefore, live K040706 may serve as a potential immunomodulatory agent against immunosuppression.

Beneficial bacteria activate type-I interferon production via the intracellular cytosolic sensors STING and MAVS

Type-I interferon (IFN-I) cytokines are produced by immune cells in response to microbial infections, cancer and autoimmune diseases, and subsequently, trigger cytoprotective and antiviral responses through the activation of IFN-I stimulated genes (ISGs). The ability of intestinal microbiota to modulate innate immune responses is well known, but the mechanisms underlying such responses remain elusive. Here we report that the intracellular sensors stimulator of IFN genes (STING) and mitochondrial antiviral signaling (MAVS) are essential for the production of IFN-I in response to lactic acid bacteria (LAB), common gut commensal bacteria with beneficial properties. Using human macrophage cells we show that LAB strains that potently activate the inflammatory transcription factor NF-κB are poor inducers of IFN-I and conversely, those triggering significant amounts of IFN-I fail to activate NF-κB. This IFN-I response is also observed in human primary macrophages, which modulate CD64 and CD40 upon challenge with IFN-I-inducing LAB. Mechanistically, IFN-I inducers interact more intimately with phagocytes as compared to NF-κB-inducers, and fail to activate IFN-I in the presence of phagocytosis inhibitors. These bacteria are then sensed intracellularly by the cytoplasmic sensors STING and, to a lesser extent, MAVS. Accordingly, macrophages deficient for STING showed dramatically reduced phosphorylation of TANK-binding kinase (TBK)-1 and IFN-I activation, which resulted in lower expression of ISGs. Our findings demonstrate a major role for intracellular sensing and STING in the production of IFN-I by beneficial bacteria and the existence of bacteria-specific immune signatures, which can be exploited to promote cytoprotective responses and prevent overreactive NF-κB-dependent inflammation in the gut.

Evaluation of Immunomodulatory Activities of the Heat-Killed Probiotic Strain Lactobacillus casei IMAU60214 on Macrophages In Vitro

Most Lactobacillus species have beneficial immunological (“immunoprobiotic”) effects in the host. However, it is unclear how probiotic bacteria regulate immune responses. The present study investigated the effects of heat-killed Lactobacillus casei IMAU60214 on the activity of human monocyte-derived macrophages (MDMs). Human MDMs were treated with heat-killed L. casei at a ratio (bacteria/MDM) of 50:1, 100:1, 250:1, and 500:1, and then evaluated for the following: NO production, by Griess reaction; phagocytosis of FITC-labeled Staphylococcus aureus particles; cytokine secretion profile (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-12p70, IL-10, and transforming growth factor (TGF)-β) by ELISA; and costimulatory molecule (CD80 and CD86) surface expression, by flow cytometry. Heat-killed L. casei IMAU60214 enhanced phagocytosis, NO production, cytokine release, and surface expression of CD80 and CD86 in a dose-dependent manner. All products were previously suppressed by pretreatment with a Toll-like receptor 2 (TLR2)-neutralizing antibody. Overall, our findings suggest that this probiotic strain promotes an M1-like pro-inflammatory phenotype through the TLR2 signaling pathway. These effects on macrophage phenotype help explain the probiotic efficacy of Lactobacillus and provide important information for the selection of therapeutic targets and treatments compatible with the immunological characteristics of this probiotic strain.

Development of a Highly Efficient Hybrid Peptide That Increases Immunomodulatory Activity Via the TLR4-Mediated Nuclear Factor-κB Signaling Pathway

Immunity is a defensive response that fights disease by identifying and destroying harmful substances or microbiological toxins. Several factors, including work-related stress, pollution, and immunosuppressive agents, contribute to low immunity and poor health. Native peptides, a new class of immunoregulatory agents, have the potential for treating immunodeficiencies, malignancies, and infections. However, the potential cytotoxicity and low immunoregulatory activity and stability of native peptides have prevented their development. Therefore, we designed three hybrid peptides (LTA_a, LTA_b, and LTA_c) by combining a characteristic fragment of LL-37 with an active Tα1 center that included Tα1 (17-24), Tα1 (20-25), and Tα1 (20-27). The best hybrid peptide (LTA_a), according to molecule docking and in vitro experiments, had improved immunoregulatory activity and stability with minimal cytotoxicity. We investigated the immunoregulatory effects and mechanisms of LTA_a using a cyclophosphamide-immunosuppressed murine model. LTA_a effectively reversed immunosuppression by enhancing immune organ development, activating peritoneal macrophage phagocytosis, regulating T lymphocyte subsets, and increasing cytokine (tumor necrosis factor-alpha, interleukin-6, and interleukin-1β) and immunoglobulin (IgA, IgG, and IgM) contents. The immunomodulatory effects of LTA_a may be associated with binding to the TLR4/MD-2 complex and activation of the NF-κB signaling pathway. Therefore, LTA_a could be an effective therapeutic agent for improving immune function.

The immune-modulating effects of viable Weissella cibaria JW15 on RAW 264.7 macrophage cells

The objective of this study is to investigate the immune-enhancing ability of viable and heat-killed Weissella cibaria JW15 (JW15) isolated from Kimchi in RAW 264.7 macrophages. The immune effects were evaluated by measuring the production of NO, cytokines, inflammatory enzyme, and activation of NF-κB. Viable JW15 executed higher activity on stimulating the release of TNF-α as well as activating NF-κB compared to that of heat-killed JW15. Additionally, viable and heat-killed JW15 significantly increased the production of NO, IL-6 and TNF-α more than that of Lactobacillus rhamnosus GG (LGG). Furthermore, viable JW15 induced higher production of iNOS compared with that of viable LGG. Collectively, our finding indicates that viable JW15 had similar, if not more, immune-enhancing activities as heat-killed JW15. In addition, viable JW15 had higher immune-enhancing activity than commercial strain LGG. Therefore, viable JW15 has the potential to be used as a functional food to improve the host immune response.

Genomic and metabolic features of Lactobacillus sakei as revealed by its pan-genome and the metatranscriptome of kimchi fermentation

The genomic and metabolic features of Lactobacillus sakei were investigated using its pan-genome and by analyzing the metatranscriptome of kimchi fermentation. In the genome-based relatedness analysis, the strains were divided into the Lb. sakei ssp. sakei and Lb. sakei ssp. carnosus lineage groups. Genomic and metabolic pathway analysis revealed that all Lb. sakei strains have the capability of producing d/l-lactate, ethanol, acetate, CO₂, formate, l-malate, diacetyl, acetoin, and 2,3-butanediol from d-glucose, d-fructose, d-galactose, sucrose, d-lactose, l-arabinose, cellobiose, d-mannose, d-gluconate, and d-ribose through homolactic and heterolactic fermentation, whereas their capability of d-maltose, d-xylose, l-xylulose, d-galacturonate, and d-glucuronate metabolism is strain-specific. All strains carry genes for the biosynthesis of folate and thiamine, whereas genes for biogenic amine and toxin production, hemolysis, and antibiotic resistance were not identified. The metatranscriptomic analysis showed that the expression of Lb. sakei transcripts involved in carbohydrate metabolism increased as kimchi fermentation progressed, suggesting that Lb. sakei is more competitive during late fermentation stage. Homolactic fermentation pathway was highly expressed and generally constant during kimchi fermentation, whereas expression of heterolactic fermentation pathway increased gradually as fermentation progressed. l-Lactate dehydrogenase was more highly expressed than d-lactate dehydrogenase, suggesting that l-lactate is the major lactate metabolized by Lb. sakei.

The Immunomodulatory Properties of Extracellular Vesicles Derived from Probiotics: A Novel Approach for the Management of Gastrointestinal Diseases

Probiotics, included in functional foods, nutritional supplements, or nutraceuticals, exhibit different beneficial effects on gut function. They are extensively used to improve the digestive processes as well as reduce the symptoms and progression of different diseases. Probiotics have shown to improve dysbiosis and modulate the immune response of the host by interacting with different cell types. Probiotics and the host can interact in a direct way, but it is becoming apparent that communication occurs also through extracellular vesicles (EVs) derived from probiotics. EVs are key for bacteria-bacteria and bacteria-host interactions, since they carry a wide variety of components that can modulate different signaling pathways, including those involved in the immune response. Interestingly, EVs are recently starting to be considered as an alternative to probiotics in those cases for which the use of live bacteria could be dangerous, such as immunocompromised individuals or situations where the intestinal barrier is impaired. EVs can spread through the mucus layer and interact with the host, avoiding the risk of sepsis. This review summarizes the existing knowledge about EVs from different probiotic strains, their properties, and their potential use for the prevention or treatment of different gastrointestinal diseases.

Arctigenin Induces an Activation Response in Porcine Alveolar Macrophage Through TLR6-NOX2-MAPKs Signaling Pathway

Arctigenin (ARG), one of the most active ingredients abstracted from seeds of Arctium lappa L., has been proved to exert promising biological activities such as immunomodulatory, anti-viral, and anti-cancer etc. However, the mechanism behind its immunomodulatory function still remains elusive to be further investigated. In this study, we found that ARG had no significant effects on the cell proliferation in both porcine alveolar macrophage cell line (3D4/21) and primary porcine derived alveolar macrophage. It remarkably increased the expression and secretion of the two cytokines including tumor necrosis factor-alpha (TNF-α) and transforming growth factor beta1 (TGF-β1) in a dose-dependent manner with the concomitant enhancement of phagocytosis, which are the indicators of macrophage activation. ARG also elevated the intracellular reactive oxygen species (ROS) production by activating NOX2-based NADPH oxidase. Furthermore, inhibition of ROS generation by diphenyliodonium and apocynin significantly suppressed ARG-induced cytokine secretion and phagocytosis increase, indicating the requirement of ROS for the porcine alveolar macrophage activation. In addition, TLR6-My88 excitation, p38 MAPK and ERK1/2 phosphorylation were all involved in the process. As blocking TLR6 receptor dramatically attenuated the NOX2 oxidase activation, cytokine secretion and phagocytosis increase. Inhibiting ROS generation almost abolished p38 and ERK1/2 phosphorylation, and the cytokine secretion could also be remarkably reduced by p38 and ERK1/2 inhibitors (SB203580 and UO126). Our finding gave a new insight of understanding that ARG could improve the immune-function of porcine alveolar macrophages through TLR6-NOX2 oxidase-MAPKs signaling pathway.

Immune-enhancing activity of C. militaris fermented with Pediococcus pentosaceus (GRC-ON89A) in CY-induced immunosuppressed model

Background

Cordyceps militaris (C. militaris) is reported to exert various immune-activities. To enhance its activity, we fermented C.militaris with Pediococcus pentosaceus ON89A (GRC-ON89A). In this study, we investigated the immune-enhancing activity GRC-ON89A, using immunosuppressed model.

Methods

Immunosuppression was induced by intraperitoneal injection of cyclophosphamide (CY). Each group was orally administered distilled water, GRC-ON89A or GRC, respectively. The phagocytic activities against IgG -opsonized FITC particles were measured using phagocytosis assay kit. The contents β-glucan, cordycepin and SCFA were measured using β-glucan kit, liquid chromatography-mass spectrometry analysis and Gas chromatography-mass spectrometry analysis, respectively.

Results

Among GRC fermented with different probiotic strains (Pediococcus pentossaceus ON89A, Lactobacillus pentosus SC64, Weissella cibaria Sal.Cla22), GRC-ON89A induced the highest elevation of nitric oxide production and enhanced phagocytic activity of RAW 264.7 cells. In primary cultured murine macrophages from normal and CY-treated mice, GRC-ON89A increased phagocytic activity, compared to that in control cells. GRC-ON89A also significantly induced the mRNA expression of TNF-α and IL-10 and the levels of phosphorylated Lyn, Syk and MAPK. The contents of β-glucan, cordycepin and SCFA in GRC significantly increased after ON89A fermentation, compared to those in unfermented GRC.

Conclusion

These results indicate that GRC-ON89A exerted the enhanced immunostimulatory activity and contained more nutritional components, compared to unfermented GRC. Our results suggested that GRC-ON89A may be applied as an agent for immune boosting therapy in immune suppressed patients.

Probiotics or pro-healers: the role of beneficial bacteria in tissue repair

Probiotics are beneficial microorganisms, known to exert numerous positive effects on human health, primarily in the battle against pathogens. Probiotics have been associated with improved healing of intestinal ulcers, and healing of infected cutaneous wounds. This article reviews the latest findings on probiotics related to their pro-healing properties on gut epithelium and skin. Proven mechanisms by which probiotic bacteria exert their beneficial effects include direct killing of pathogens, competitive displacement of pathogenic bacteria, reinforcement of epithelial barrier, induction of fibroblasts, and epithelial cells' migration and function. Beneficial immunomodulatory effects of probiotics relate to modulation and activation of intraepithelial lymphocytes, natural killer cells, and macrophages through induced production of cytokines. Systemic effects of beneficial bacteria and link between gut microbiota, immune system, and cutaneous health through gut-brain-skin axes are discussed as well. In light of growing antibiotic resistance of pathogens, antibiotic use is becoming less effective in treating cutaneous and systemic infections. This review points to a new perspective and therapeutic potential of beneficial probiotic species as a safe alternative approach for treatment of patients affected by wound healing disorders and cutaneous infections.

Mixed Lactobacillus plantarum Strains Inhibit Staphylococcus aureus Induced Inflammation and Ameliorate Intestinal Microflora in Mice

Objective. Staphylococcus aureus is an important pathogen that causes intestinal infection. We examined the immunomodulatory function of single and mixed Lactobacillus plantarum strains, as well as their impacts on the structure of the microbiome in mice infected with Staphylococcus aureus. The experiment was divided into three groups: protection, treatment, and control. Serum IFN-γ and IL-4 levels, as well as intestinal sIgA levels, were measured during and 1 week after infection with Staphylococcus aureus with and without Lactobacillus plantarum treatment. We used 16s rRNA tagged sequencing to analyze microbiome composition. IFN-γ/IL-4 ratio decreased significantly from infection to convalescence, especially in the mixed Lactobacillus plantarum group. In the mixed Lactobacillus plantarum group the secretion of sIgA in the intestine of mice (9.4-9.7 ug/mL) was significantly higher than in the single lactic acid bacteria group. The dominant phyla in mice are Firmicutes, Bacteroidetes, and Proteobacteria. Treatment with mixed lactic acid bacteria increased the anti-inflammatory factor and the secretion of sIgA in the intestine of mice infected with Staphylococcus aureus and inhibited inflammation.

White ginseng extract induces immunomodulatory effects via the MKK4-JNK pathway

Panax ginseng Meyer (white ginseng) is a popular functional food and its biological effects on the human body have been noted for hundreds of years. In the present study, the underlying mechanisms responsible for the immunomodulatory effects of white ginseng extract (WGE) were investigated. WGE increased NO production via upregulation of iNOS expression levels. Mouse cytokine array results also revealed that the expression of 13 cytokines was elevated by WGE treatment in IFN-γ-primed macrophage cells. Although both MKK4-JNK and MEK-ERK signaling pathways were activated after treatment with WGE, only the MKK4-JNK signaling pathway appears to have any significant immunomodulatory significance. Oral administration of WGE for 28 days recovered cyclophosphamide (CY)-induced suppression of the immune system in mice via the MKK4-JNK pathway. Taken together, these findings suggest that the MKK4-JNK signaling pathway is a crucial mechanism of WGE-induced immunomodulation.

Heat Killed Lactobacillus reuteri GMNL-263 Reduces Fibrosis Effects on the Liver and Heart in High Fat Diet-Hamsters via TGF-β Suppression

Obesity is one of the major risk factors for nonalcoholic fatty liver disease (NAFLD), and NAFLD is highly associated with an increased risk of cardiovascular disease (CVD). Scholars have suggested that certain probiotics may significantly impact cardiovascular health, particularly certain Lactobacillus species, such as Lactobacillus reuteri GMNL-263 (Lr263) probiotics, which have been shown to reduce obesity and arteriosclerosis in vivo. In the present study, we examined the potential of heat-killed bacteria to attenuate high fat diet (HFD)-induced hepatic and cardiac damages and the possible underlying mechanism of the positive effects of heat-killed Lr263 oral supplements. Heat-killed Lr263 treatments (625 and 3125 mg/kg-hamster/day) were provided as a daily supplement by oral gavage to HFD-fed hamsters for eight weeks. The results show that heat-killed Lr263 treatments reduce fatty liver syndrome. Moreover, heat-killed Lactobacillus reuteri GMNL-263 supplementation in HFD hamsters also reduced fibrosis in the liver and heart by reducing transforming growth factor β (TGF-β) expression levels. In conclusion, heat-killed Lr263 can reduce lipid metabolic stress in HFD hamsters and decrease the risk of fatty liver and cardiovascular disease.