Probiotics and Antimicrobial Proteins最新文献

Irritable bowel disease (IBD), also known as ulcerative colitis and Crohn's disease, is a chronic inflammatory disorder affecting millions of people worldwide. Herein, nano-encapsulated multi-strain probiotics formulation, comprising Bifidobacterium breve DSM24732 and B. coagulans SANK 70258 and L. plantarum DSM24730 (BBLNPs) is used as an effective intervention technique for attenuating IBD through gut microenvironment regulation. The efficacy of the prophylactic role of BBLNPs in alleviating injury induced by dextran sulfate sodium (DSS) was evaluated by assessing oxidative and inflammatory responses, levels of short-chain fatty acids (SCFAs) and their regulation on GPR41/43 pathway, expression of genes related to tight-junctions and autophagy, immunohistochemistry of IL1β and GPR43, and histological examination of inflamed colonic tissue. The severity of clinical signs and paracellular permeability to FITC (fluorescein isothiocyanate)-labeled dextran was significantly decreased after BBLNP treatment. Reduction of oxidative stress-associated biomarkers (MDA, ROS, and H₂O₂) and acceleration of antioxidant enzyme activities (SOD, CAT, and GSH-Px) were noted in the BBLNP-treated group. Subsiding of inflammatory markers (TNF-α, IL-18, IL-6, TRL-4, CD-8, NLRP3, and caspase 1) and upregulation of tight-junction-related genes (occludin and JAM) was detected in BBLNPs. Administration of BBLNPs remarkably resulted in a higher level of SCFAs which parrel with colonic upregulation of GPR41 and GPR43 expression compared to DSS-treated rats. Notable modulation of autophagy-related genes (p62, mTOR, LC3, and Beclin-1) was identified post BBLNP treatment. The mRNA expressions of p62 and mTOR were significantly downregulated, while LC3 and Beclin-1 were upregulated after prophylactic treatment with BBLNPs. Immune-stained labeled cells showed lower expression of IL-1β and higher expression levels of GPR43 in BBLNPs compared to the DSS-induced group. The intestinal damage caused by DSSwas effectively mitigated by oral BBLNP treatment, as supported by the restoration of healthy colonic tissue architecture. The findings suggest that BBLNPs have a promising avenue in the remission of IBD by modulating inflammation, oxidative stress, microbial metabolites such as SCFAs, and autophagy.

This study evaluated the probiotic characteristics of Lactiplantibacillus plantarum strains, revealing strong acid and bile salt tolerance and significant adhesion to HT-29 cells. In addition, the anti-melanogenic and antioxidant properties of their cell-free supernatants (CFS) were investigated in vitro. Melanogenesis assays were performed in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 melanoma cells, while antioxidant activity was evaluated in H₂O₂-stimulated HaCaT keratinocytes. CFS treatment inhibited melanin synthesis, tyrosinase activity, and expression of melanogenesis-related genes, including MITF, Tyr, Trp1, and Trp2. These effects were attributed to the suppression of cAMP-response element-binding protein (CREB)/microphthalmia-associated transcription factor (MITF) and mitogen-activated protein kinase (MAPK; ERK, JNK, and p38) signaling pathways. Antioxidant activity was observed via nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway activation, resulting in elevated levels of downstream targets such as HO-1, NAD(P)H:quinone oxidoreductase (NQO1), and thioredoxin reductase 1 (TXNRD1). High-performance liquid chromatography (HPLC) analysis identified lactic acid and acetic acid as the primary metabolites in the CFS associated with these biological effects. These findings suggest that culture supernatants derived from probiotics may serve as natural agents with skin-whitening and antioxidant properties, supporting their potential application in food, pharmaceutical, and cosmetic industries.

In this study, four lactic acid bacteria (LAB) strains demonstrating ciprofloxacin, bile salt, gastric fluid, and intestinal fluid tolerance as well as adhesion ability to Caco-2 and HT-29 cells were used to improve and recover the intestinal flora disorders caused by ciprofloxacin, among which, Lactobacillus brevis 505 exhibited excellent adhesion ability to two kinds of cells and colonization ability to mouse intestinal. After ciprofloxacin treatment, certain recovery effect on cecum caused by ciprofloxacin in the mice was found during natural recovery (group 5C2), but it was challenging to fully restore the intestinal integrity to the initial level. After L. brevis 505 intervention (group 5C5), the intestinal damage to the colon and ileum caused by ciprofloxacin in mice was significantly alleviated; the recovery effect was better than that of natural recovery. Additionally, L. brevis 505 could effectively regulate INF-γ, sIgA, and RegIIIγ increase induced by ciprofloxacin. Shannon and Simpson index of the intestinal flora of mice in 5C5 group were higher than those in other group, the relative abundance of Bifidobacterium and Lactobacillus in the mice in 5C5 group was increased, indicating that LAB can better restore the structure and abundance of intestinal microflora. Consequently, L. brevis 505 shows promise as a probiotic for gut microbiota restoration and rebuilding during antibiotic therapy.

Probiotics play an important role in animal growth, immunity, and gut microbial balance and are now widely used in agriculture, food, and medicine. This study analysed the effects of different concentrations of Tibetan sheep compound probiotics on the immunity, tissue morphology, and intestinal microbiota of mice using histological, molecular, and 16S rRNA techniques. The results showed that the composite probiotics sourced from Tibetan sheep improved the growth performance of mice, increased the length of small intestinal villi and mucosal thickness, and enhanced the intestinal barrier function of mice. DZ-L and DZ-M significantly increased the mRNA expression levels of ZO-1, Occludin, and Claudin-1 mRNA. They also up-regulated IL-10 and TNF-β, and down-regulated TNF-α, IL-1β, and IL-8. The immune function of mice was enhanced, with DZ-M treatment having an extremely significant effect, while the effect of DZ-H treatment was slightly lower compared to DZ-L and DZ-M. In addition, the composition and diversity of the intestinal microbiota were modulated, and at the phylum level, the relative abundance of Firmicutes was higher in the DZ-M group, the relative abundance of Desulfobacterota, Actinobacteriota, and Patescibacteria was reduced in the probiotic complex group, and the relative abundance of Verrucomicrobiota was higher. At the genus level, the relative abundance of Muribaculaceae was higher in the DZ-L and DZ-M groups, and the relative abundance of Lachnospiraceae_NK4A136_group in the DZ-H group; and the relative abundance of Bacteroides and Roseburia in the composite probiotic group. This study can improve the reference for the development of new green feed additives instead of antibiotics, which will also further promote the development of the livestock industry.

Though numerous bacteria have been used as probiotics by industries, at present, Saccharomyces boulardii and Saccharomyces cerevesiae are the only yeast probiotics which are industrially exploited. In view of this, yeast probiotics were isolated from traditional fermented foods and products collected from different parts of Karnataka, India. In this work, we have studied the probiotic attributes of ten yeast isolates isolated from different traditionally fermented foods and products. About 73 yeast isolates were initially isolated by serially diluting the samples and plating on the Potato Dextrose Agar (PDA) plates. The spot assay was performed to screen the yeast isolates against test pathogens. Ten isolates were selected based on their significant antimicrobial activity. These isolates were subjected to biochemical characterization and then assessed for probiotic properties. The ability of probiotics to endure at pH 2.0 and tolerate bile conditions (0.3%) are crucial attributes for the survival in the gastrointestinal tract (GIT). The yeast isolates were also assessed for cell surface hydrophobicity and autoaggregation capabilities. All the ten isolates showed endurance in GIT tract and > 40% of adhesion. The study further examined cholesterol assimilation, antioxidant and antagonistic properties of the yeasts. Subsequently, the molecular characterization was performed by isolating the DNA of yeast isolates by phenol-chloroform method and identified molecularly through sequencing of D1/D2 regions. The isolates tested negative for gelatinase and DNase and were non-haemolytic indicating they are safe for consumption. Among ten isolates, Meyerozyma guillermondii (MYSY23), Meyerozyma caribbica (MYSY22) and Meyerozyma guillermondii (MYSY19) showed significant results for all probiotic and functional characteristics with greater than 65% survivability in GIT tract and > 50% of antagonistic activity against test pathogens and also proved non-cytotoxic and safe. These findings suggest that yeasts with significant probiotic attributes could be recommended for various probiotic application.

The current study was designed to explore the biosynthetic potential of sevadicin in Bacillus pumilus species and its interaction with bacterial drug target molecules. The non-ribosomal peptide (NRP) cluster in B. pumilus SF-4 was preliminarily confirmed using PCR-based screening, and the bioactivity of strain SF-4 culture extract was assessed against a set of human pathogenic strains. The susceptibility assay showed that strain SF-4 extract had higher inhibitory concentrations (312-375 µg/mL) than ciprofloxacin. Genome mining of B. pumilus strains (n = 22) using AntiSMASH and BAGEL identified sevadicin coding biosynthetic gene cluster only in strain SF-4, constitutes of two core biosynthetic genes, three additional biosynthetic genes, two transport-related genes, and one regulatory gene. The molecular docking of sevadicin with various putative bacterial drug targets such as dihydropteroate, muramyl ligase E, topoisomerase, penicillin-binding protein, and in vitro safety analyses were conducted with detailed ADMET screening. The results showed that sevadicin makes hydrophobic interaction with MurE (PDB ID: 1E8C and 4C13) via hydrogen bonding, suggesting bacterial growth inhibition by disrupting the cell wall synthesis pathway and exhibiting a secure biosafety profile. The stability and compactness of sevadicin/MurE complexes were assessed via molecular dynamic simulation using RMSD, RMSF, and Rg. The simulation results revealed the binding stability of sevadicin/MurE complexes and indicated that the complexes can't be easily deformed. In conclusion, the current study explored the biosynthesis of sevadicin in B. pumilus for the first time and found that sevadicin inhibits bacterial growth by inhibiting cell wall synthesis via targeting the MurE enzyme and exhibits no toxicity.

Plant defensins are small antimicrobial proteins (AMP) that participate in the immune defense of plants through their antibacterial, antiviral and antifungal activities. PgD1 is a defensin from Picea glauca (Canadian Pine) and has antifungal activity against plant pathogens. This activity positions it as an alternative biotechnological agent to pesticides commonly used against these plant fungi diseases. The present study aimed to recombinantly produce PgD1 in Escherichia coli to characterize its in vitro antifungal potential against different phytopathogens. To achieve this, the coding gene was amplified and cloned into pET30a( +). Recombinant plasmid was subsequently introduced into E. coli for the soluble expression of defensin PgD1. To evaluate the antifungal activity of the expressed protein, the growth inhibition test was used in solid and liquid media for approximately 7 days against significant plant pathogens, that cause significant crop damage including: Botrytis cinerea, Colletotrichum gloeosporioides, Colletotrichum musae, Colletotrichum graminicola and Fusarium oxysporum. Additionally, stability assessments included temperature variation experiments and inhibition tests using dithiothreitol (DTT). The results showed that there was significant inhibition of the fungal species tested when in the presence of PgD1. Furthermore, defensin proved to be resistant to temperature variations and demonstrated that part of its stability is due to its primary structure rich in cysteine ​​residues through the denaturation test with dithiothreitol (DTT) where the antifungal activity of PgD1 defensin was inhibited. These data indicate that recombinant PgD1 could be utilized as a plant protection technology in agriculture.

This study aimed to characterize two types of postbiotics from Lactobacillus acidophilus LA-5 prepared in De Man, Rogosa, and Sharpe (MRS-Pb) and UF cheese whey (W-Pb). We compared the chemical compositions, functional properties, and toxicities of the prepared probiotics. Assessments included antimicrobial and antioxidant activities, total and individual phenolic compounds, volatile compounds, individual free amino acids, and organic acid contents. Cytotoxicity and potential effects on cell proliferation were assessed using MTT and wound healing assays in HCT-116 intestinal epithelial cancer cells. The results revealed differences in the chemical composition of the two postbiotics. Citric, lactic, and butyric acids were the main organic acids in W-Pb, whereas malic and acetic acids were the main organic acids in MRS-Pb. High levels of hydrocarbons were found in MRS-Pb. W-Pb exhibited potent antimicrobial activity against Listeria monocytogenes and Escherichia coli than MRS-Pb, while the antioxidant potential of MRS-Pb was higher than that of W-Pb. L. acidophilus postbiotics significantly reduced HCT-116 cell viability in a dose-dependent manner (10, 20, and 40 mg/mL for MRS-Pb and 10 and 20 mg/mL for W-Pb). MRS-Pb exhibited more potent effects and cytotoxicity than W-Pb did. Postbiotics did not affect HCT-116 cell proliferation or migration. Both postbiotics increased TAC in a concentration-dependent manner in treated cells, with MRS-Pb showing a stronger effect. These results suggest that the type of culture medium can significantly affect the bioactive properties, chemical composition, and toxicity of postbiotics.

Probiotics are live microorganisms that, when administered in adequate amounts, can bring health benefits to the host. Most of these organisms are found naturally in the human gastrointestinal tract. Escherichia coli strains Nissle 1917 (EcN), and CEC15 have shown beneficial effects in murine models of intestinal inflammation, such as colitis and mucositis. The present study evaluated the effects as postbiotic of heat-inactivated and cell-free supernatant preparations of EcN and CEC15 in attenuating 5-fluorouracil (5-FU)-induced intestinal mucositis in mice and compared them with the probiotic effects of the live preparations. BALB/c mice were fed, by daily gavage, with 10¹⁰ CFU of live or inactivated bacteria or with 300 µL of cell-free supernatant for 12 days. On the 10th day, all animals, except for the control group, received an intraperitoneal injection of 5-FU (300 mg/kg). After 72 h of 5-FU administration, animals were euthanized, and the ileum and blood were collected for analysis. Treatments with live and heat-inactivated CEC15 mitigated weight loss, preserved intestinal length, reduced histological damage, maintained goblet cells, decreased neutrophil infiltration, and modulated expression of inflammatory and barrier genes when compared to 5-FU mucositis controls. EcN showed more limited effects. CEC15 upregulated mRNA expression of the mucin MUC2 and tight junction protein TJP1. CEC15 demonstrated protective effects against 5-FU-induced mucositis, whether administered with live, heat-inactivated, or cell-free supernatant. This suggests that CEC15 mediates a protective response via secreted metabolites and does not require viability. The postbiotic forms of CEC15 present advantages for use in immunocompromised patients. This study elucidates the anti-inflammatory and barrier-protective effects of CEC15 against intestinal mucositis.

Suanshui is a traditional fermented vegetable food in the southwest of China that is a rich source of probiotics. This study aimed to screen probiotics from Suanshui that have a protective effect against liver injury using in vivo and in vitro experiments. Eleven strains were isolated according to acid-producing capacity and probiotic properties, including antibacterial activity against pathogenic bacteria, tolerance to artificial gastrointestinal fluid and bile salts, heat resistance, antioxidant capacity, hydrophobicity, autoaggregation capacity, and adhesion capacity. Three probiotic strains, LAB36 (Lacticaseibacillus paracasei, (L. paracasei)), LAB19 (Lactiplantibacillus plantarum (L. plantarum)), and LAB51 (Limosilactobacillus fermentum (L. fermentum)), were obtained by the TOPSIS comprehensive evaluation. Furthermore, in an in vitro model of inflammation induced by LPS treatment of AML12, metabolites derived from the intestinal contents of mice treated with the three strains significantly decreased the gene expression of IL-1β, TNF-α, and Caspase 3 in the LAB (19, 36, 51) + LPS group (P < 0.05) and significantly increased the gene expression of Bcl-2 compared with those in the untreated LPS group (P < 0.05). In addition, the LAB36 + LPS group also exhibited significantly decreased gene expression of TLR4 and Bax (P < 0.05). In vivo experiments, LAB36 pretreatment significantly decreased the levels of ALT, AST, and inflammatory factors (IL-1β and IL-6) in the serum, improved the antioxidant capacity, and reduced apoptosis in the livers of the model mice (liver injury induced by D-GalN/LPS). In summary, LAB36 isolated from Suanshui has a protective effect on liver injury.