Probiotic Bacillus amyloliquefaciens mediate M1 macrophage polarization in mouse bone marrow-derived macrophages

Harnessing and Mimicking Bacterial Features to Combat Cancer: From Living Entities to Artificial Mimicking Systems

Bacterial-derived micro-/nanomedicine has garnered considerable attention in anticancer therapy, owing to the unique natural features of bacteria, including specific targeting ability, immunogenic benefits, physicochemical modifiability, and biotechnological editability. Besides, bacterial components have also been explored as promising drug delivery vehicles. Harnessing these bacterial features, cutting-edge physicochemical and biotechnologies have been applied to attenuated tumor-targeting bacteria with unique properties or functions for potent and effective cancer treatment, including strategies of gene-editing and genetic circuits. Further, the advent of bacteria-inspired micro-/nanorobots and mimicking artificial systems has furnished fresh perspectives for formulating strategies for developing highly efficient drug delivery systems. Focusing on the unique natural features and advantages of bacteria, this review delves into advances in bacteria-derived drug delivery systems for anticancer treatment in recent years, which has experienced a process from living entities to artificial mimicking systems. Meanwhile, a summary of relative clinical trials is provided and primary challenges impeding their clinical application are discussed. Furthermore, future directions are suggested for bacteria-derived systems to combat cancer.

Novel 3D Flipwell system that models gut mucosal microenvironment for studying interactions between gut microbiota, epithelia and immunity

Gut mucosa consists of stratified layers of microbes, semi-permeable mucus, epithelium and stroma abundant in immune cells. Although tightly regulated, interactions between gut commensals and immune cells play indispensable roles in homeostasis and cancer pathogenesis in the body. Thus, there is a critical need to develop a robust model for the gut mucosal microenvironment. Here, we report our novel co-culture utilizing 3D Flipwell system for establishing the stratified layers of discrete mucosal components. This method allows for analyzing synchronous effects of test stimuli on gut bacteria, mucus, epithelium and immune cells, as well as their crosstalks. In the present report, we tested the immuno-stimulatory effects of sepiapterin (SEP, the precursor of the cofactor of nitric oxide synthase (NOS)-BH₄) on the gut mucosal community. We previously reported that SEP effectively reprogrammed tumor-associated macrophages and inhibited breast tumor cell growth. In our co-cultures, SEP largely promoted mucus integrity, bacterial binding, and M1-like polarization of macrophages. Conversely, these phenomena were absent in control-treated cultures. Our results demonstrate that this novel co-culture may serve as a robust in vitro system to recapitulate the effects of pharmacological agents on the gut mucosal microenvironment, and could potentially be expanded to test the effects outside the gut.

The Nocardia Rubra Cell Wall Skeleton Regulates Macrophages and Promotes Wound Healing

The Nocardia rubra cell wall skeleton (Nr-CWS) is an immunomodulator used clinically for its ability to modulate the body's immune function. Macrophages are an important hub of the immune response during wound healing. In this study, we hypothesized that a Nr-CWS could modulate macrophage physiological activities, polarize macrophages toward M2, and promote wound healing. Through in vivo experiments, we made two full-thickness excisional wounds on the backs of mice; one was treated with a Nr-CWS, and the other was treated with saline. We photographed and recorded the wound change every other day. We observed the histopathological examination and collagen deposition using H&E and Masson staining, then analyzed the macrophage surface markers using immunofluorescence. Through in vitro experiments, we studied the effect of the Nr-CWS on RAW264.7 cells through CCK8, transwell, flow cytometry, western blot, immunofluorescence, and ELISA. We found that the Nr-CWS can enhance the proliferation, migration, and phagocytosis of macrophages. In addition, it can promote the recruitment of macrophages on the wound surface, polarize macrophages to M2, and increase the expression of pro-healing cytokines. Ultimately, the Nr-CWS accelerated wound healing.

Contribution of Lactobacilli on Intestinal Mucosal Barrier and Diseases: Perspectives and Challenges of Lactobacillus casei

The intestine barrier, the front line of normal body defense, relies on its structural integrity, microbial composition and barrier immunity. The intestinal mucosal surface is continuously exposed to a complex and dynamic community of microorganisms. Although it occupies a relatively small proportion of the intestinal microbiota, Lactobacilli has been discovered to have a significant impact on the intestine tract in previous studies. It is undeniable that some Lactobacillus strains present probiotic properties through maintaining the micro-ecological balance via different mechanisms, such as mucosal barrier function and barrier immunity, to prevent infection and even to solve some neurology issues by microbiota-gut-brain/liver/lung axis communication. Notably, not only living cells but also Lactobacillus derivatives (postbiotics: soluble secreted products and para-probiotics: cell structural components) may exert antipathogenic effects and beneficial functions for the gut mucosal barrier. However, substantial research on specific effects, safety and action mechanisms in vivo should be done. In clinical application of humans and animals, there are still doubts about the precise evaluation of Lactobacilli's safety, therapeutic effect, dosage and other aspects. Therefore, we provide an overview of central issues on the impacts of Lactobacillus casei (L. casei) and their products on the intestinal mucosal barrier and some diseases and highlight the urgent need for further studies.

Characterization of exosomes derived from IPEC-J2 treated with probiotic Bacillus amyloliquefaciens SC06 and its regulation of macrophage functions

Probiotics can maintain or improve health by modulating the response of immune cells in the gastrointestinal tract. However, the mechanisms by which probiotics promote macrophage (Mφ) activity are poorly understood. Here, we evaluated exosomes derived from intestinal epithelial cells treated with Bacillus amyloliquefaciens SC06 (Ba) and investigated the regulation of Mφ phagocytosis, apoptosis, and polarization. We isolated two exosomes from intestinal porcine epithelial cell lines (IPEC-J2) with or without Ba-treatment, named Ba-Exo and Exo, respectively. They had typical sizes and a cup-shaped morphology, and their surfaces presented typical exosomes-associated proteins, including CD63, ALIX, and TSG101. Ba-Exo and Exo could entrer Mφ (3D4/21 cells) effectively. Moreover, an in vitro phagocytosis assay demonstrated that Ba-Exo can promote phagocytosis of Mφ. Similar to Exo, Ba-Exo had no effect on Mφ apoptosis. Furthermore, Ba-Exo significantly increased inducible nitric oxide synthase (iNOS), declined the expression of arginase 1 (Arg1) in Mφ, and stimulated Mφ polarization to M1. To explore the differences in the regulation of Mφ polarization between Ba-Exo and Exo, we performed reverse transcription quantitative polymerase chain reaction analysis of the small RNAs and found that miR-222 increased in the Ba-Exo group compared to that in the Exo group. These results provide a new perspective on the relationship between probiotics and intestinal immunity.

Probiotics as multifaceted oral vaccines against colon cancer: A review

Probiotics are known as the live microorganisms that, upon adequate administration, elicit a health beneficial response inside the host. The probiotics are known as immunomodulators and exhibit anti-tumor properties. Advanced research has explored the potential use of probiotics as the oral vaccines without the latent risks of pathogenicity. Probiotic-based oral vaccines are known to induce mucosal immunity that prevents the host from several enteric infections. Probiotic bacteria have the ability to produce metabolites in the form of anti-inflammatory cytokines, which play an important role in the prevention of carcinogenesis and in the activation of the phagocytes that eliminate the preliminary stage cancer cells. This review discusses the advantages and disadvantages of using the oral probiotic vaccines as well as the mechanism of action of probiotics in colon cancer therapy. This review also employs the use of “PROBIO” database for selecting certain probiotics with immunomodulatory properties. Furthermore, the use of several probiotic bacteria as anti-colon cancer adjuvants has also been discussed in detail. Because the current studies and trials are more focused on using the attenuated pathogens instead of using the probiotic-based vaccines, future studies must involve the advanced research in exploiting the potential of several probiotic strains as adjuvants in cancer therapies.

Probiotics Bring New Hope for Atherosclerosis Prevention and Treatment

Cardiovascular disease is the leading cause of human mortality and morbidity worldwide. Atherosclerosis (AS) is the underlying pathological responsible in most acute and severe cardiovascular diseases including myocardial infarction and stroke. However, current drugs applied to the treatment of AS are not clinically effective, and there is a large residual risk of cardiovascular disease and multiple side effects. Increasing evidence supports a close relationship between microorganisms and the incidence of AS. Recent data have shown that probiotics can improve multiple key factors involved in the development and progression of AS, including cholesterol metabolism imbalance, endothelial dysfunction, proinflammatory factor production, macrophage polarization, intestinal flora disturbance, and infection with pathogenic microorganisms, and therefore probiotics have attracted great interest as a novel potential “medicine”. This review is aimed at summarizing the effects of probiotics on various influencing factors, and providing valuable insights in the search for early prevention and potential therapeutic strategies for AS.

Advances of bacteria-based delivery systems for modulating tumor microenvironment

The components and hospitable properties of tumor microenvironment (TME) are associated with tumor progression. Recently, TME modulating vectors and strategies have garnished significant attention in cancer therapy. Although a pilot work has reviewed TME regulation via nanoparticle-based delivery systems, there is no systematical review that summarizes the natural bacteria-based anti-tumor system to modulate TME. In this review, we conclude the strategies of bacterial carriers (including whole bacteria, bacterial skeleton and bacterial components) to regulate TME from the perspective of TME components and hospitable properties, and the clinical trials of bacteria-mediated cancer therapy. Current challenges and future prospects for the design of bacteria-based carriers are also proposed that provide critical insights into this natural delivery system and related translation from the bench to the clinic.

Gut immune homeostasis: the immunomodulatory role of Bacillus clausii, from basic to clinical evidence

INTRODUCTION

The gut microbiota affects the development of the gut immune system in early life. Perturbations to microbiota structure and composition during this period can have long-term consequences on the health of the individual, through its effects on the immune system. Research in the last few decades has shown that probiotic administration can reverse these effects in strain- and environment-specific ways. Bacillus clausii (B. clausii) has been in use for many decades as a safe and efficacious probiotic, but its mode of action has not yet been completely elucidated.

AREAS COVERED

In this review, we discuss how the gut immune system works, the factors that affect its functioning, and the plethora of research highlighting its role in various diseases. We also discuss the known modes of action of Bacillus probiotics, and highlight the preclinical and clinical evidence that reveal how B. clausii acts to bolster gut defense.

EXPERT OPINION

We anticipate that the treatment and/or prevention of dysbiosis will be central to managing human health and disease in the future. Discovering the pathophysiology of autoimmune diseases, infections, allergies, and some cancers will aid our understanding of the key role played by microbial communities in these diseases.

Lactobacillus plantarum RS-09 Induces M1-Type Macrophage Immunity Against Salmonella Typhimurium Challenge via the TLR2/NF-κB Signalling Pathway

Lactobacillus plantarum can interact with macrophages against bacterial enteropathy due to its potential ability to modulate macrophage polarization. However, this mechanism is not completely understood. TLR2 can recognize microbial components and trigger macrophage cytokine responses to different gram-positive strains. The aim of this study was to investigate whether probiotic Lactobacillus plantarum RS-09 can induce macrophage polarization against Salmonella Typhimurium infection via TLR2 signalling. BALB/c mice were preadministered RS-09 continuously for 7 days and then infected with Salmonella Typhimurium ATCC14028. Mouse RAW264.7 mononuclear macrophages were stimulated with RS-09 and coincubated with ATCC14028 or PBS controls. The results of the in vivo study indicated that RS-09 could relieve S. Typhimurium-induced splenomegaly, body weight loss and death rate. RS-09 also limited the colonization and translocation of S. Typhimurium in the gastrointestinal tract and thereby protected against infection. We also observed that RS-09 upregulated the production of M1 macrophage characteristics (e.g., CD11c and IL-6) against S. Typhimurium. Furthermore, RS-09 induced the expression of TLR2 in macrophages. In an in vitro study, treatment of RAW264.7 cells with RS-09 either concurrently with or before S. Typhimurium challenge enhanced the secretion of Reactive oxygen species and Nitric oxide. This effect was related to TLR2 and NF-κB activation. Based on these findings, Lactobacillus plantarum RS-09 was shown to modulate M1 macrophage polarization and induce TLR2-linked NF-κB signalling activity in the innate immune response to S. Typhimurium infection.

Effects of Bacillus amyloliquefaciens TL106 Isolated from Tibetan Pigs on Probiotic Potential and Intestinal Microbes in Weaned Piglets

Bacillus amyloliquefaciens is a nonpathogenic microorganism whose highly active amylase is widely isolated from soil and plants. TL106 is an isolate of Bacillus amyloliquefaciens isolated from cold- and disease-resistant Tibetan pigs in Linzhi, Tibet. Here, we report that TL106 not only could survive in acidic environments, high bile salt concentrations, and high-temperature conditions but also was resistant to antibiotics. It significantly improved the growth performance of weaned piglets, especially in the prevention of diarrhea. The crude fiber and crude ash digestibility in weaned piglets after TL106 administration was considerably higher than that in other groups. The results of 16S rRNA sequencing conveyed that TL106 stabilized gut microbiota that was disturbed by the weaning process with an increased level of Lachnospiraceae, Peptococcaceae.rc4_4, Erysipelotrichaceae.L7A_E11, and Mollicutes.RF39. Hence, this study proved that Bacillus amyloliquefaciens TL106 might be a candidate for antibiotics in Duroc×Landrace×Yorkshire weaned piglets. IMPORTANCE Antibiotics are often used to promote animal growth and prevent diarrhea in weanling piglets. Nevertheless, intestinal pathogenic bacterial resistance and drug residues caused by antibiotic overuse are worthy of concern and demand an urgent solution. Bacillus amyloliquefaciens TL106 has been isolated from cold- and disease-resistant Tibetan pigs in Linzhi, Tibet. It significantly improved the growth performance, decreased diarrhea, increased the absorption of crude substances, and regulated the gut flora homeostasis in Duroc×Landrace×Yorkshire weaned piglets. As an antibiotic candidate, TL106 perfectly displayed its probiotic potential and pollution-free properties.

Effects of Probiotics BaSC06 on Intestinal Digestion and Absorption, Antioxidant Capacity, Microbiota Composition, and Macrophage Polarization in Pigs for Fattening

This study aimed to compare the effects of BaSC06 and antibiotics on growth, digestive functions, antioxidant capacity, macrophage polarization, and intestinal microbiota of pigs for fattening. A total of 117 pigs for fattening with similar weight and genetic basis were divided into 3 groups: Anti group (containing 40 g/t Kitasamycin in the diet), Anti+Ba group (containing 20 g/t Kitasamycin and 0.5 × 108 CFU/kg BaSC06 in the diet) and Ba group (containing 1 × 108 cfu/Kg BaSC06 in the diet without any antibiotics). Each treatment was performed in three replicates with 13 pigs per replicate. Results showed that BaSC06 replacement significantly improved the ADG (P < 0.05), intestinal digestion and absorption function by increasing the activity of intestinal digestive enzymes and the expression of glucose transporters SGLT1 (P < 0.05) and small peptide transporters PEPT1 (P < 0.05). Besides, BaSC06 supplementation enhanced intestinal and body antioxidant capacity by activating the Nrf2/Keap1 antioxidant signaling pathway due to the increased expression of p-Nrf2 (P < 0.05). Notably, BaSC06 alleviated intestinal inflammation by inhibiting the production of pro-inflammatory cytokines, IL-8, IL-6, and MCP1 (P < 0.05), and simultaneously increasing the expression of M1 macrophage marker protein iNOS (P < 0.05) and M2 macrophage marker protein Arg (P < 0.05) in the intestinal mucosa. Moreover, BaSC06 promoted the polarization of macrophages to M2 phenotype by stimulating the STAT3 signaling pathway. It was also noted that BaSC06 improved microbiota composition by enhancing the proportion of Firmicutes, and reducing that of Bacteroidetes and Proteobacteria. Taken together, our results indicate that dietary supplementation of BaSC06 in pigs for fattening improves the growth, mucosal structure, antioxidative capacity, immune functions (including increasing M1 and M2 polarization of macrophage) and composition of intestinal microbiota, which is much better than antibiotics, suggesting that it is an effective alternative to antibiotics in the preparation of pig feed.

Lactobacillus rhamnosus GG promotes M1 polarization in murine bone marrow-derived macrophages by activating TLR2/MyD88/MAPK signaling pathway

Lactobacillus rhamnosus GG (LGG) is increasingly applied in functional food products and acts as a probiotic model in nutritious and clinical studies. Increasing evidences have revealed the immune modulation of LGG on macrophages. The aim of this study is to investigate the effect of LGG on macrophage polarization of murine bone marrow-derived macrophages (BMDMs). BMDMs were treated with 10⁸ colony-forming units (CFU)/ml LGG for 1.5, 3, and 6 hr. Results showed that LGG obviously upregulated the mRNA expression of M1-associated cytokines (p < .05), including interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNF-α), and inducible nitric oxide synthase (iNOS), whereas had no effect on the expression of M2-associated markers (p > .05), including arginase 1 (Arg1), mannose receptor, and chitinase-like protein 3 (YM1). Furthermore, LGG markedly increased the expression of pro-inflammatory cytokines (IL-12p40, cyclooxygenase-2 [COX-2], and interferon-γ [IFN-γ]) (p < .05) and anti-inflammatory cytokines (IL-10, IL-4, and transforming growth factor-β [TGF-β]) (p < .05). In addition, we also found that TLR2/MyD88/MAPK signaling pathway was required for LGG-induced M1 macrophage polarization and M1-related cytokines expression. Together, these findings demonstrate that probiotic LGG facilitates M1 polarization of BMDMs, suggesting that LGG may have an immunotherapeutic potential in regulating the host defense against pathogen invasion.

Curdlan (Alcaligenes faecalis) (1→3)-β-d-Glucan Oligosaccharides Drive M1 Phenotype Polarization in Murine Bone Marrow-Derived Macrophages via Activation of MAPKs and NF-κB Pathways

Functional oligosaccharides, particularly curdlan (1→3)-β-d-glucan oligosaccharides (GOS), play important roles in modulating host immune responses. However, the molecular mechanisms underlying the immunostimulatory effects of GOS on macrophage polarization are not clear. In this work, GOS (5–1000 µg/mL) were non-toxic to bone marrow-derived macrophages (BMDMs) with improved pinocytic and bactericidal capacities. Incubation with GOS (100 µg/mL) induced M1 phenotype polarization of BMDMs as evidenced by increased CD11c⁺/CD86⁺ (10.1%) and M1 gene expression of inducible nitric oxide synthase, interleukin (IL)-1β, and chemokine C-C-motif ligand 2. Accordingly, the secretion of cytokines IL-1β, IL-6, monocyte chemotactic protein-1, and tumor necrosis factor-α, as well as the nitrite release of BMDMs were increased by GOS (100 µg/mL). Expression of mitogen-activated protein kinases (MAPKs) of phosphorylated (p)-c-Jun amino-terminal kinase, p-extracellular signal regulated kinase, and p-p38 in BMDMs were increased by GOS, as well as the p-Stat1. Moreover, nuclear factor-kappa B (NF-κB) p-p65 expression in BMDMs was promoted by GOS while it suppressed IκBα expression. Receptor blocking with anti-CR3 (CD11b/CD18) and anti-toll-like receptor (TLR) 2 antibodies diminished GOS induced M1 phenotype polarization with reduced mRNA expression of M1 genes, decreased cytokine and nitrite releases, and suppressed signaling pathway activation. Thus, CR3 (CD11b/CD18) and TLR2 mediated activation of MAPKs and NF-κB pathways are responsible for GOS induced polarization of BMDMs.

Probiotic Bacillus Attenuates Oxidative Stress- Induced Intestinal Injury via p38-Mediated Autophagy

Probiotics have been widely used in maintaining intestinal health and one of their benefits is to enhance host antioxidant capacity. However, the involved molecular mechanisms require further investigated. Autophagy is a self-protection process in response to diverse stresses. We hypothesized that probiotics could modulate intestinal autophagy to alleviate oxidative stress. Sprague-Dawley (SD) rats were orally administered Bacillus SC06 or SC08 daily for 24 days and thereafter received an intraperitoneal injection of diquat (DQ) to induce oxidative stress. We found that rats administered Bacillus SC06 showed more significant intestinal tissue repair and antioxidant properties than those administered SC08, which suggests a strain-specific effect of probiotics. Moreover, SC06 alleviated apoptosis by regulating the expression of Bcl2, Bax and cleaved caspase-3. Further investigations revealed that SC06 triggered autophagy, indicated by the upregulation of LC3 and Beclin1 and the degradation of p62 in rat jejunum and IEC-6 cells. Preincubation with autophagy inhibitor 3-methyladenine (3-MA) significantly aggravated reactive oxygen species (ROS) production and apoptotic cell formation. Furthermore, we demonstrated that p38 MAPK (mitogen-activated protein kinase), not AKT (alpha serine/threonine kinase)/mTOR (mammalian target of rapamycin), was involved in SC06-induced autophagy. Taken together, Bacillus SC06 can alleviate oxidative stress-induced disorders and apoptosis via p38-mediated autophagy. The above findings highlight a novel mechanism underlying the beneficial effects of probiotics as functional food and provide a new perspective on the prevention and treatment of oxidative damages.

Bacillus amyloliquefaciens Ameliorates H2O2-Induced Oxidative Damage by Regulating Transporters, Tight Junctions, and Apoptosis Gene Expression in Cell Line IPEC-1

Probiotics have always been considered as a supplementary therapy for many diseases especially gut disorders. The absorption and barrier function of the gut play a vital role in the maintenance of body homeostasis. This study was to investigate the protective effects of Bacillus amyloliquefaciens SC06 (Ba) on H₂O₂-induced oxidative stress on intestinal porcine epithelial cells (IPEC-1) based on the level of gene expression. We demonstrated that Ba was a safe probiotic strain in the first place. Results showed that treatment with H₂O₂ significantly increased the mRNA expression of absorptive transporters glucose transporter 2 (GLUT2), Ala/Ser/Cys/Thr transporter 1 (ASCT1), and ASCT2 compared with the control group. Meanwhile, oxidative stress induced a significant improvement in the mRNA expression of occludin (OCLN) and caspase-3, and remarkably inhibited the expression of L-type amino acid transporter 1 (LAT1) or B cell lymphoma-2 (Bcl-2), respectively. Pretreatment with Ba dramatically reversed the disturbance induced by oxidative stress on the mRNA expression of ASCT1, ASCT2, and OCLN, which also significantly prevented H₂O₂-inhibited LAT1 and Bcl-2 mRNA expression. However, Ba failed to exert any significant protective effect on GLUT2 and caspase-3 mRNA expression. We concluded that pretreatment with Ba could alleviate the damage caused by oxidative stress to a certain extent and conferred a protective effect to the intestine.

Protective effect of Bacillus amyloliquefaciens against Salmonella via polarizing macrophages to M1 phenotype directly and to M2 depended on microbiota

Bacillus amyloliquefaciens SC06 (BaSC06), a potential probiotic, plays a positive role in animal growth performance and immune function.

Glycyrrhizin Attenuates Salmonella enterica Serovar Typhimurium Infection: New Insights Into Its Protective Mechanism

Glycyrrhizin (GL), a triterpenoid glycoside, serves important functions in various biological activities, including antiviral and antitumor immune responses. However, the anti-inflammatory effects of GL on Salmonella enterica serovar Typhimurium (ST)-induced injury in mice and the mechanisms underlying the protection of GL are poorly understood. Here, we investigated the effects of GL on host immune responses against ST infection in mice. A phenotypic analysis using hematoxylin and eosin (H&E) staining and transmission electron microscopy showed that GL relieved ST-induced weight loss and intestinal mucosal injury. A colonization assay showed that GL significantly reduced ST colonization in the ileum and colon and translocation to the liver and spleen. An antibacterial activity assay and real-time PCR revealed that GL had no direct inhibitory impact on ST growth or virulence gene expression. ELISA showed that GL pretreatment significantly decreased proinflammatory cytokine (IFN-γ, TNF-α, IL-6) secretion and increased anti-inflammatory cytokine (IL-10) secretion in the ileum, colon and serum of ST-infected mice. Moreover, flora analysis showed that GL reduced Akkermansia, Sutterella, Prevotella and Coprococcus but enriched Parabacteroides and Anaerotruncus in the cecum of ST-infected mice. These results suggest that GL promotes the secretion of immune factors and modulates intestinal flora to prevent further ST infection. We also analyzed the effect of GL on immunocytes and found that GL promoted the phenotypic and functional maturation of murine bone marrow-derived dendritic cells (BMDCs). Flow cytometry and western blotting demonstrated that NF-κB, ERK, and p38 MAPK were required for GL-induced BMDC maturation. The above findings indicate that GL attenuates ST infection by modulating immune function and intestinal flora. This study enriches our current knowledge of GL-mediated immunological function and provides a new perspective on the prevention of Salmonella infection in animals and humans.

The Influence of Probiotic Lactobacilli and Flaxseed on the Health of Weaned Piglets and Metabolism of Polyunsaturated Fatty Acids (PUFAs)

This study investigated for 14 days post-weaning, the influence of dietary supplementation of synbiotics in the form of probiotic cheeses containing cultures of L. plantarum and L. fermentum and crushed flaxseed (source of ω-3 polyunsaturated fatty acids — PUFAs and fibre) on 36 commercial piglets originating from an infected herd (Coronavirus and E. coli) during the critical period of weaning. We focused on the health and metabolism of PUFAs in this critical period of a piglet’s life. The dietary supplementation positively affected: the overall health state of weaners, reduced diarrhoea by 29 % by 14 days post-weaning and significantly increased the counts of lactic acid bacteria, bifidobacteria and the production of volatile fatty acids. The PUFA concentrations in the m. biceps femoris of the piglets were analysed by gas chromatography. High levels of ω-3 alpha-linolenic acid (ALA) in flaxseed increased significantly the level of ALA, eicosapentaenic acid (EPA) and docosahexaenic acid (DHA) in the pig muscles on days 7 and 14 post-weaning. The levels of ω-6 linolenic acid (LA) were less affected by the diet, but were increased on day 14 post-weaning, while the conversion products of LA, and arachidonic acid (AA), were decreased on days 7 and 14. The increased level of dietary ALA favoured the activity of Δ-6-desaturase for the conversion of ALA to EPA and DHA, at the expense of AA synthesis from LA. The ability of synbiotics to incorporate high levels of DHA in the pig muscles appear prospective for improving the nutritional properties of pork and reducing the occurrence of civilization diseases in consumers of this product of animal origin.

Cellulolytic potential of probiotic Bacillus Subtilis AMS6 isolated from traditional fermented soybean (Churpi): An in-vitro study with regards to application as an animal feed additive

The aim of the present study is to evaluate the probiotic attributes of Bacillus subtilis AMS6 isolated from fermented soybean (Churpi). This isolate exhibited tolerance to low pH (pH 2.0) and bile salt (0.3%), capability to autoaggregate and coaggregate. AMS6 also showed highest antibacterial activity against the pathogenic indicator strain Salmonella enterica typhimurium (MTCC 1252) and susceptibility towards different antibiotics tested. The isolate was effective in inhibiting the adherence of food borne pathogens to Caco-2 epithelial cell lines, and was also found to be non-hemolytic which further strengthen the candidature of the isolate as a potential probiotic. Further studies revealed B. subtilis AMS6 showed cellulolytic activity (0.54±0.05 filter paper units mL(-1)) at 37°C. The isolate was found to hydrolyze carboxymethyl cellulose, filter paper and maize (Zea mays) straw. The maize straw digestion was confirmed by scanning electron microscopy studies. The isolate was able to degrade filter paper within 96h of incubation. A full length cellulase gene of AMS6 was amplified using degenerate primers consisting of 1499 nucleotides. The ORF encoded for a protein of 499 amino acids residues with a predicted molecular mass of 55.04kDa. The amino acids sequence consisted of a glycosyl hydrolase family 5 domain at N-terminal; Glycosyl hydrolase catalytic core and a CBM-3 cellulose binding domain at its C terminal. The study suggests potential probiotic B. subtilis AMS6 as a promising candidate envisaging its application as an animal feed additive for enhanced fiber digestion and gut health of animal.

Evaluation of the potential anti-allergic effects of heat-inactivated Lactobacillus paracasei V0151 in vitro, ex vivo, and in vivo

The efficacy of Lactobacillus paracasei V0151 (V0151), isolated from the faeces of a child, to modulate immune responses was investigated. In RAW 264.7 cells expressing an inducible nitric oxide synthase (iNOS)-directed luciferase gene, heat-inactivated V0151 stimulated iNOS expression followed by nitric oxide production. V0151 significantly elevated interferon gamma, interleukin (IL)-10, tumour necrosis factor alpha, and IL-1β production in human peripheral blood mononuclear cells. In splenocytes isolated from ovalbumin (OVA)-sensitised BALB/c mice treated with OVA and V0151 at different bacterium-to-cell ratios (1:1, 10:1, and 20:1) for 96 h, IL-2, IL-4, IL-5, and IL-13 production was dose-dependently downregulated, whereas IL-12 was dose-dependently upregulated. Collectively, our findings indicate that V0151 might regulate pro-inflammatory factors in macrophages and splenocytes. Furthermore, the T helper 1/T helper 2 (Th1/Th2) balance was also skewed toward Th1 dominance through the elevation of Th1 cytokine production.

In vitro evaluation of celluloytic Bacillus amyloliquefaciens AMS1 isolated from traditional fermented soybean (Churpi) as an animal probiotic

A microorganism showing probiotic attributes and hydrolyzing carboxymethylcellulose was isolated from traditional fermented soybean (Churpi) and identified as Bacillus amyloliquefaciens by analysis of 16S rRNA gene sequence and named as B. amyloliquefaciens AMS1. The potentiality of this isolate as probiotic was investigated in vitro and it showed gastrointestinal transit tolerance, cell surface hydrophobicity, cell aggregation and antimicrobial activity. The isolate was found to be non-hemolytic which further strengthens its candidature as a potential probiotic. The maize straw digestion was confirmed by scanning electron microscopy studies. The isolate was able to degrade filter paper within 96 hours of incubation. This study explores the possibility of combining the cellulase degrading ability of a microbe with its probiotic attributes to enhance gut health of animal and digestibility of the feed.

Immunomodulation therapy of diabetes by oral administration of a surfactin lipopeptide in NOD mice

Type 1 diabetes mellitus (T1DM) is considered an autoimmune disease, which can be attenuated by modulation of immune pathway from Th1- to Th2-type through vaccination. WH1fungin surfactin is a Bacillus-produced natural immunomodulator. NOD mice were orally treated with 5mg/kg or 25mg/kg WH1fungin once a week for total 4 weeks. After the final administration, the diabetes incidence and the anti-inflammatory roles of WH1fungin were investigated by immunohistochemistry, FACS and ELISA. The results showed oral WH1fungin obviously resulted in a WH1fungin-unspecific suppression of T1DM. Diabetes incidence was significantly reduced when compared to phosphate buffered saline (PBS) control. Mice in the control group began to be onset of diabetes at week 15, following with an increased mortality from week 16 to 28. At the end of observation, the diabetes incidence reached to 81% at week 30, while only 25% in WH1fungin groups. The splenocytes assay showed oral WH1fungin could suppress T cells proliferation, down-regulate amounts of activated CD8(+) T cells with the production of tumor necrosis factor (TNF)-α and interferon (IFN)-γ, and increase CD4(+)CD25(+)FOXP3(+) regulator T cells (Tregs). The serum assay revealed oral WH1fungin down-regulated TNF-α and IgG2a but increased interleukin (IL)-10 and IgG1 in mice. All of these data showed oral WH1fungin tended to switch the immune response from Th1- to Th2-type. The further surveys revealed that less IFN-γ but more transfer growth factor (TGF)-β were found in the islets of mice with oral WH1fungin when compared to that in the control group. As a result, the normal islet architecture and slight inflammatory cells infiltration was observed with a slight insulitis in the oral WH1fungin groups. These results demonstrate that oral WH1fungin might be a novel therapeutic approach for the prevention of T1DM.

The regulatory peptide pidotimod facilitates M2 macrophage polarization and its function

Pidotimod is a synthetic dipeptide with biological and immunological activity in innate immune responses. It has been reported that pidotimod could promote functional maturation of dendritic cells, but little is known about the regulation of macrophages. Recent studies have demonstrated that M1 or M2 polarized macrophages are of great importance for responses to microorganism infection or host mediators. The aim of this study was to determine the effectiveness of pidotimod on mouse bone marrow-derived macrophage polarization and its function. The results showed that pidotimod had no influence on M1-polarized macrophage. While interestingly, a significant increase of M2 marker gene expression (Arg1, Fizz1, Ym1, MR) was observed (p < 0.01) in IL-4-induced M2 macrophage treated with pidotimod. In addition, cell surface expression of mannose receptor was dramatically enhanced using fluorescence activated cell sorter (FACS) analysis. Furthermore, the function of M2 macrophage was also determinated. The results showed that the supernatant of pidotimod-treated M2 macrophage could increase the migration (p < 0.05) and enhance the wound closure rate (p < 0.05) of MLE-12 cells. Collectively, it could be concluded that pidotimod significantly facilitated IL-4-induced M2 macrophage polarization and improves its function.

Probiotic Bacillus amyloliquefaciens SC06 Prevents Bacterial Translocation in Weaned Mice

Probiotic is a preparation containing microorganisms that confers beneficial effect to the host. This work assessed whether oral administration of Bacillus amyloliquefaciens SC06 (Ba) could decrease bacterial translocation in weaned mice. Weaned C57BL/6 were randomly allocated into three groups: group I as the control group, group II were treated with 0.85 % NaCl. Group III was administered with probiotic Ba 1 × 10(9) CFU/day dissolved in 100 μl of 0.85 % NaCl for 30 days. Mice were then sacrificed, and tissue were cultured to determine bacterial translocation. Meanwhile, splenic CD4(+)T cells, CD8(+)T cells, B cells, and macrophages were analysised by FACS. Our results showed that probiotic Ba significantly reduced bacteria translocation compared with the control group and 0.85 % NaCl group (P < 0.05), lower levels of bacteria were detected in the MLN, liver, spleen, and kidney of mice. Moreover, significant increase in percentage and number of macrophages were observed in the spleen of Ba-treated mice compared with the control and 0.85 % NaCl groups. Together, these data indicated that Ba could decrease bacterial translocation in weaned mice. This effect seems to be correlated with the changes of macrophage numbers.