Search Results (64)

Chinese steamed bread (CSB) is an important fermented wheat product, but controlled strategies for modulating its volatile profile remain limited. This study evaluated defined composite sourdoughs comprising Wickerhamomyces anomalus CRFSZY16 or Kluyveromyces marxianus FYY7 in combination with Lactiplantibacillus plantarum SDgsM3 for CSB production using the direct fermentation method (DFM) and the refrigerated sponge-dough method (RSDM). Technological stress tolerance, preliminary safety-related phenotypes, acidification capacity, volatile organic compounds (VOCs), multivariate profiles, and specific volume were assessed. SDgsM3 showed dough-relevant stress tolerance and rapid acidification, while both yeasts tolerated moderate fermentation stresses. Headspace solid-phase microextraction coupled with gas chromatography-triple quadrupole mass spectrometry (HS-SPME-GC-TQ-MS) revealed stage-dependent remodeling of volatile profiles from mature sourdough to fully proofed main dough and final CSB. RSDM selectively modified representative alcohols, aldehydes, furans, ketones, and esters rather than uniformly increasing all VOCs. In the final CSB, the K. marxianus-based RSDM system showed relatively higher levels of 3-methyl-1-butanol, whereas the W. anomalus-based RSDM system showed relatively higher levels of hexanal, nonanal, 1-hexanol, and 2-pentylfuran. Composite sourdough treatments also yielded specific volumes of 2.56–2.66 mL/g versus 2.44 mL/g for the commercial yeast control. These findings demonstrate strain- and process-dependent modulation of CSB volatile profiles and support flavor-oriented composite sourdough design. Full article

Background: Current understanding of the biotransformation of bioactive compounds in Portulaca oleracea through probiotic fermentation remains limited, and the anti-diarrheal mechanisms of the resulting fermented products have yet to be fully elucidated. Methods: In this exploratory study, we employed untargeted metabolomics together with a senna-induced acute diarrhea mouse model to investigate P. oleracea co-fermented with Lactiplantibacillus plantarum and Bacillus subtilis. Results: Metabolomic profiling identified 220 metabolites significantly altered by fermentation, predominantly comprising increased levels of lipids, phenylpropanoids, and polyketides. Compared with the unfermented P. oleracea control, fermented P. oleracea (FP) effectively reduced the diarrhea index, lowered serum levels of inflammatory cytokines (IL-1β, IL-6, TNF-α) and neurotransmitters (5-HT, substance P), and restored Na⁺/K⁺ balance as well as ileal histomorphology. Transcriptomic analysis and RT-qPCR validation further demonstrated that FP modulated the expression of genes involved in focal adhesion, PI3K-Akt, cGMP-PKG, and mineral absorption pathways. Conclusions: Fermented P. oleracea (FP) alleviates acute diarrhea through multi-target mechanisms. Notably, fermentation endows P. oleracea with markedly superior intestinal protective effects relative to the unfermented counterpart. These findings provide preliminary experimental evidence supporting the potential of fermented P. oleracea as a candidate for intestinal protective functional food research. Full article

Lactic acid bacteria-fermented food materials are promising sources of functional ingredients, but the active components underlying their bioactivity often remain unclear. We localized the macrophage-stimulatory activity of a red pepper-based fermentate prepared with Lactiplantibacillus plantarum CJLP243. Compared with the unfermented matrix and a non-fermented matrix supplemented with freeze-dried CJLP243, the fermentate induced greater IL-6 and TNF-α production in J774A.1 macrophages. Activity was reproducibly concentrated in the pellet-derived lysate-insoluble fraction (PDIF) and remained in residual debris after solvent extraction. LTA-directed fractionation and analytical screening did not support lipoteichoic acid as the principal determinant. Lysozyme markedly reduced activity, whereas proteinase K had a partial effect, a pattern consistent with a lysozyme-sensitive, cell wall-associated structure or cell wall–matrix complex, within which peptidoglycan-associated material remains a plausible candidate; contributions from co-associated components cannot be excluded. Targeted metabolomics revealed fermentation-associated changes in pellet-associated amino acid pools, consistent with broader adaptation of amino acid and nitrogen metabolism during fermentation; their biochemical linkage to cell-wall precursor pathways provides metabolic support rather than direct structural evidence. These findings identify a reproducible, process-linked insoluble fraction with macrophage-stimulatory activity and provide a framework for developing and standardizing fermentation-derived functional food ingredients. Full article

This study aimed to identify novel antimicrobial peptides (AMPs) from Lactiplantibacillus plantarum K9, isolated from Protaetia brevitarsis seulensis larvae, using genome and transcriptome analyses. L. plantarum K9, among the isolated lactic acid bacteria from P. brevitarsis larvae, showed the strongest antimicrobial activity, with MIC₉₀ values of 22 μL against E. coli and 21 μL against S. aureus. Approximately 54% of the antimicrobial activity was attributed to peptides or proteins. Genome analysis revealed a 3 Mb chromosome and three plasmids. Screening of hypothetical proteins using CAMP_R4 identified 18 AMP candidates. Transcriptomic analysis showed that most AMP genes were more highly expressed in the stationary phase and were upregulated under low-pH conditions. Antimicrobial assays using synthetic peptides demonstrated that AMP4, 6, 7, 12-2, 14, and 18 exhibited strong activity against S. aureus, whereas AMP16 and 18 were effective against E. coli. After cloning each AMP and assessing its antimicrobial activity, the cloned AMPs exhibited overall greater antimicrobial activity against S. aureus than against E. coli. Among all candidates, AMP12 displayed the strongest antimicrobial activity and high specificity toward S. aureus. Structural analysis revealed a conserved α-helical region that is likely responsible for membrane-targeting antimicrobial activity. Collectively, these findings suggest that L. plantarum K9 AMP12 is a novel antimicrobial peptide that contributes to the strain’s antimicrobial properties. Full article

Probiotic lactic acid bacteria are widely recognized for their health-promoting effects. However, the use of live microorganisms may pose safety concerns and stability limitations. Consequently, postbiotics, defined as inactivated microbial cells and/or their components, have emerged as a promising alternative. This study integrates genome-guided evaluation of probiotic potential, experimental validation of in silico predictions and process optimization for the production of inactivated Lactiplantibacillus plantarum DM1 and KK1 cells as postbiotics. Genome mining identified genes and gene clusters associated with metabolic versatility, antimicrobial activity, gastrointestinal stress tolerance, adhesion and prebiotic substrate utilization. Building on these findings, to generate postbiotics, the efficiency of thermal, enzymatic, mechanical and radiation-based inactivation methods was evaluated in bacterial suspensions prepared in three dairy by-product matrices: milk permeate, sweet whey and sour whey. Complete inactivation of both strain cells was achieved by thermal treatment (3 min pasteurization), γ-irradiation (3 kGy), and combined lysozyme–pasteurization treatment, whereas other treatments showed partial and matrix-dependent effects. Matrix composition significantly influenced treatment efficacy, suggesting a protective role of food components used. These findings highlight the importance of combining genome mining for potential probiotic strain characterization with robust, matrix-adapted inactivation strategies for the development of stable postbiotic formulations. Full article

Gingivitis, periodontitis, and stomatitis are common oral inflammatory disease affecting a large proportion of the global population. Increasing attention has recently been given to the development of health functional materials aimed at maintaining oral health and preventing microbial-associated oral disease. This study evaluated the efficacy of the lipoteichoic acid (LTA) fraction derived from the probiotic Lactiplantibacillus plantarum K8 (pLF) in preventing oral inflammation and microbial infection using the oral epithelial cell line YD-38. The results confirmed that pLF enhances the expression of interleukin-1 receptor-associated kinase M (IRAK-M), a negative regulator of Toll-like receptor (TLR) signaling, and inhibits the expression of pro-inflammatory cytokines, including C-C motif ligand 2 (CCL2), interleukin-6 (IL-6), and interleukin-8 (IL-8), in YD-38 cells stimulated with tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Furthermore, it was demonstrated that pLF induces IRAK-M expression in a TLR2-involved manner and inhibits nuclear factor-kappa B (NF-κB) signaling, thereby reducing the expression of pro-inflammatory cytokines. pLF also exhibits oral antimicrobial efficacy by increasing the expression of the antimicrobial peptide human β-defensin 1 (hBD1) and human β-defensin 2 (hBD2) in a TLR2-involved manner and effectively inhibiting the growth of Porphyromonas gingivalis and Staphylococcus aureus in the epithelial cell associated system. Therefore, the LTA fraction derived from L. plantarum K8 represents a promising postbiotic candidate for the regulation of oral immune and microbial responses. Full article

This study investigated the effects of Lactiplantibacillus plantarum SJ-4 inoculation, partial replacement of sodium chloride (NaCl) with potassium chloride (KCl) and calcium ascorbate (CaA), and their combined treatment on the fermentation quality of fermented pork sour meat. Microbial community and metabolomic analyses were further integrated to explore the potential mechanisms related to flavor formation and quality changes. The combined treatment (LP + K-Ca group) improved the flavor profile, increased the contents of volatile compounds and free amino acids, reduced several undesirable flavor-related compounds, and contributed to better fermentation quality. Compared with the control group (C), total free amino acids and essential amino acids in the LP + K-Ca group increased by 4.95% and 22.71%, respectively, while the contents of undesirable compounds such as 2-nonenal, hypoxanthine, and ketones decreased by 73.65%, 73.40%, and 9.58%, respectively. Key flavor-related microorganisms included Macrococcus, Staphylococcus, and Lactiplantibacillus. These microorganisms are intricately linked to metabolic products such as amino acids, fatty acids, and organic acids, which may provide important precursors for volatile flavor formation. Overall, the combined treatment of 40% NaCl replacement with 24% KCl and 16% CaA, together with 2% L. plantarum SJ-4 inoculation, showed potential for improving flavor formation and fermentation quality in salt-reduced sour meat based on partial NaCl replacement. Full article

Freeze-drying is a crucial technique for preserving bacterial strains, yet its efficiency depends heavily on the precise selection of protective agents. This study aimed to optimize freeze-drying conditions for the commercially relevant, non-GMO strain Lactiplantibacillus plantarum K KKP/593/p. The cryoprotective effects of glycerol, dimethyl sulfoxide (DMSO), and trehalose were evaluated, alongside various carriers including skim milk powder, maltodextrin, inulin, and starch. Survival rates were determined using the plate count method on MRS agar, complemented by scanning electron microscopy (SEM) for microstructural analysis. Results indicated that skim milk powder was the superior carrier, significantly outperforming polysaccharides. Among the protective agents, glycerol exhibited the highest efficacy, while trehalose and DMSO were suboptimal. The most effective formulation 20% glycerol without prior incubation combined with skim milk powder at 0.75:1 (w/w, total mass) ratio maintained maximum viability with no statistically significant decrease. SEM observations confirmed that this synergistic combination ensured a stable, porous matrix favorable for rehydration. These findings emphasize that while synergistic multi-component systems are essential for maximizing post-process viability, cryoprotective formulations must be empirically tailored to specific bacterial strains to ensure industrial efficiency. Full article

Pork production is closely linked to skeletal muscle growth and anabolic processes. This study investigated the effects of dietary supplementation with a multi-strain probiotic (Lactiplantibacillus plantarum, Streptococcus thermophilus, and Bacillus subtilis) on the growth performance, carcass traits, gut microbiota, and potential signaling pathways in growing pigs. A total of 144 weaning piglets (28 days old) were randomly allocated to two groups and fed diets with or without probiotics (0.1%) for 18 weeks. Pigs fed with probiotics showed significantly improved feed efficiency (p < 0.05) and greater muscle mass in the loin eye, arm shoulder, and blade shoulder regions. Microbiome analysis revealed significant enrichment of short-chain fatty acid (SCFA)-producing taxa, including Acidaminococcus, Allisonella, Dialister, and Megasphaera, alongside an increased cecal butyrate level in pigs fed probiotics. Integrated fecal microbiome and serum metabolomics analysis demonstrated that the metabolite profile was substantially altered by the supplementation of probiotics. Additionally, serum insulin levels, expression of the bile acid receptor tgr5, and upstream genes in the PI3K/Akt/mTOR pathway (igf1r, insr, and pi3k) were significantly upregulated (p < 0.05). Collectively, these results suggest that a multi-strain probiotic supplementation may be a promising strategy for improving muscle deposition and feed efficiency in commercial pig production. Full article

Background and aims: Lactiplantibacillus plantarum is a widely studied probiotic species with well-documented benefits for gastrointestinal function and immune modulation. However, probiotic effects are strain-specific, and the safety of newly identified strains must be clinically established. L. plantarum K014, isolated from traditionally fermented vegetables, has not previously been evaluated in human subjects. This study aimed to evaluate the safety and tolerability of L. plantarum K014 in healthy Malaysian adults by assessing its effects on anthropometric measures, hematological indices, liver and renal function, gastrointestinal health, and selected immune-related outcomes, including the incidence and severity of common cold symptoms. Methods: This single-center, randomized, double-blind, placebo-controlled trial was conducted over a 6-month period. Of 304 healthy adults screened, 152 were enrolled and randomized in a 1:1 ratio to receive either L. plantarum K014 (≥1 × 10⁹ CFU/day) or placebo (maltodextrin), administered daily in sachet form; 125 participants completed the study. Clinical assessments, including physical examination, anthropometric measurements, and blood analyses, were performed at baseline, Month 4, and Month 6. Gastrointestinal symptoms, stool characteristics, and immune-related outcomes were monitored weekly using structured online questionnaires. Results: L. plantarum K014 was well tolerated, with no probiotic-related adverse events reported. No clinically significant changes were observed in body weight, BMI, hematological indices, or renal function in either group. Exploratory analyses indicated that participants receiving L. plantarum K014 exhibited statistically significant differences in several liver function markers, as well as lower severity of diarrhea and abdominal pain compared with placebo, though these findings were not prespecified efficacy endpoints and should be interpreted cautiously. Similarly, lower weekly ratings of common cold symptoms interfering with work or study were observed in the probiotic group as an exploratory observation. Conclusions: Daily consumption of L. plantarum K014 at a dose of ≥1 × 10⁹ CFU for six months was safe and well tolerated in healthy adults. The absence of adverse effects, together with observed trends toward lower gastrointestinal discomfort and immune-related symptoms, supports the suitability of L. plantarum K014 for further investigation in efficacy-driven clinical studies. Full article

Kefir grains are a valuable source of exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) with potential applications in fermented dairy products. In this study, LAB isolated from kefir grains originating from five regions were screened for EPS production and probiotic-related properties. Three strains, Lactiplantibacillus plantarum XZ61, Lactobacillus kefiranofaciens EG10, and Lentilactobacillus kefiri EG12, were selected based on high EPS yield, antimicrobial activity, antioxidant capacity, and tolerance to acidic and bile salt conditions. After optimization, the highest EPS yield (539.57 μg/mL) was obtained from strain EG10.The purified EPS consisted of two molecular weight fractions (≈1.4 and 23~25 kDa) and was rich in mannose (33.38~61.58%). Among the three EPS, EG10-EPS exhibited superior emulsifying and flocculating properties comparable to commercial stabilizers, as well as notable ABTS^•+ and hydroxyl radical scavenging activities. Furthermore, co-fermentation of L. kefiranofaciens EG10 with conventional yogurt starter cultures significantly improved exopolysaccharide content, water-holding capacity, texture, and antioxidant activity of fermented milk, particularly in cow milk. These results demonstrate the potential of kefir-derived EPS-producing LAB as natural functional cultures for fermented dairy applications. Full article

Lactiplantibacillus plantarum LP28 (LP28), isolated from traditional Taiwanese dried tofu, has been demonstrated to have substantial probiotic potential because it increases the production of short-chain fatty acids (SCFAs) and strengthens anti-inflammatory responses. In this study, the safety of LP28 was assessed using both in vitro and in vivo approaches, including whole-genome sequence analysis, the Ames bacterial reverse mutation assay, a chromosomal aberration test, a rodent peripheral blood micronucleus test, a 28-day subacute oral toxicity assay, and an assessment of hemolytic activity. In vitro phenotypic evaluation revealed that LP28 exhibited no hemolytic activity and was susceptible to all the tested antibiotics except kanamycin. In vivo assessments revealed no significant alterations in reticulocyte counts or micronuclei incidence in ICR mice, and SD rats exhibited no subacute toxicity at an oral LP28 dosage of 2000 mg/kg body weight/day for 28 days. Moreover, a whole-genome sequence analysis of LP28 revealed the absence of antimicrobial resistance genes, harmful virulence factors, and genes associated with biogenic amine synthesis. Additionally, the presence of genes involved in stress responses (e.g., acid, bile salt, heat, osmotic, and oxidative stresses) and adhesion-related genes was confirmed. Furthermore, LP28 contains six genes (plnA, plnE, plnF, plnJ, plnK, and plnN) that encode bacteriocin precursor peptides, suggesting the potential for enhanced probiotic effects through the production of antimicrobial plantaricins. These findings highlight the potential of LP28 as a safe and effective probiotic for human consumption. Full article

Background/Objectives: Severe and recurrent infections due to multidrug-resistant (MDR) Pseudomonas aeruginosa necessitate alternative antimicrobial strategies. Fermented cacao beans represent a niche microbial ecosystem with the potential to harbor beneficial lactic acid bacteria (LAB). This study aimed to isolate and characterize LAB strains from fermented cacao beans in southern Thailand and to evaluate their probiotic potential and antimicrobial activity against MDR P. aeruginosa. Methods and Results: Five Lactiplantibacillus plantarum isolates were identified via MALDI-TOF MS and whole-genome sequencing (WGS). All strains demonstrated antimicrobial activity against 17 clinical MDR P. aeruginosa isolates and CR14 exhibited the largest inhibition zone. The isolates displayed robust probiotic traits, including survival under simulated gastrointestinal conditions. Acid tolerance (pH 2.0) reached 61.15 ± 7.75%, while resistance to pepsin, pancreatin, and bile salts exceeded 88%, 91%, and 92%, respectively. Strong adhesion was confirmed via auto-aggregation (55.02 ± 1.75%), hydrophobicity (45.58 ± 0.96%) and Caco-2 cell attachment (up to 98.11 ± 3.28%). WGS revealed multiple plantaricin-encoding clusters. Coarse-grained molecular dynamic simulations showed that two-peptide plantaricins (plnJ/K and plnNC8-αβ) self-assembled and formed stable pores in bacterial membrane models, confirming a pore-forming antimicrobial mechanism. The strains lacked acquired resistance genes and virulence factors, confirmed by in silico safety assessments. Conclusions: Thus, these L. plantarum strains are promising probiotics for managing MDR P. aeruginosa via functional foods or adjunct therapies. Full article

Carrot wastes contain valuable bioactive compounds, particularly carotenoids, phenolics, and dietary fibre, whose concentration and bioaccessibility can be enhanced through structural and biochemical modifications induced by thermophysical and biological treatments, providing valorization potential. This study evaluated the effects of microwave treatment (1.5 or 3 W/g for 2, 4, and 6 min), ultrasound treatment (100 or 200 g at 40 kHz for 5, 10, or 15 min), and lactic acid fermentation with Lactiplantibacillus plantarum, Ligilactobacillus salivarius, and Limosilactobacillus reuteri for 48 h on the plant cell structure and physicochemical and antioxidant properties of fresh-cut carrot wastes. Among the tested strains, L. salivarius showed the highest growth after 24 h of fermentation (from 8.8 to 9.7 log₁₀ CFU/g), increasing total phenolic content by 1.3-fold. Antioxidant activity improved, with DPPH peaking at 48 h (2.7-fold) and ABTS increasing from early fermentation stages. Ultrasounds enhanced antioxidant properties, so that 100 g–15 min led to maximum increases in total phenols, flavonoids, and ABTS (fold-increase of 1.3, 2.7, and 1.4, respectively), while DPPH values peaked after 5 min (70% increase). Microwave treatment at 3 W/g increased total phenols and flavonoids 1.3-fold, although prolonged exposure reduced antioxidant activity. Overall, selected thermophysical and fermentation treatments may enhance the bioactive potential of carrot wastes. Full article

This study investigated the biochemical composition and antioxidant potential of flours from pigment-deficient Chlorella vulgaris variants (honey and white) and wild-type (green) and the impact of lactic acid bacteria–yeast co-culture fermentation. The three variants were characterized for composition, total polyphenol (TPC) and flavonoid (TFC) contents, antioxidant capacity (DPPH, FRAP, and ORAC assays), and reactive oxygen species production in HT-29 intestinal cells. All extracts were noncytotoxic up to 100 µg/mL. Among all variants, the green showed the highest native TPC, TFC, and overall antioxidant activity. TPC and TFC were similar between honey and white, while FRAP was higher in honey and ORAC was higher in white. Biomasses were subsequently fermented for 24 h using Lactiplantibacillus plantarum CR L1 or Levilactobacillus brevis L204 with either Saccharomyces cerevisiae TRE Y100 or Kluyveromyces marxianus MK Y55. Fermentation resulted in significant pH reduction and increases in titratable acidity and lactic acid production, particularly in co-cultures involving K. marxianus. However, the effects on antioxidant properties were strongly matrix-dependent, with significant increases in TPC and antioxidant activity observed only in the white variant. Overall, pigmentation and microbial pairing emerged as key determinants of metabolic outcomes. These findings highlight the potential of co-culture fermentation to enhance the bioactive profile of pigment-deficient C. vulgaris, supporting their application in functional foods. Full article