Search Results (387)

Background/Objectives: Estrogen deficiency contributes to dyslipidemia and visceral adiposity, increasing cardiovascular risk in postmenopausal women. Sargassum fulvellum (Sf), a brown seaweed rich in bioactive compounds, possesses lipid-regulating properties that may be enhanced by lactic acid bacteria fermentation. This study aimed to evaluate the effects of fermented S. fulvellum (SfLlLm), prepared using Lactococcus lactis and Leuconostoc mesenteroides, on lipid metabolism and adipose tissue remodeling in an ovariectomized (OVX) mouse model of estrogen deficiency. Methods: Female C57BL/6 mice underwent ovariectomy and were fed an AIN-76A diet supplemented with either unfermented Sf or SfLlLm for eight weeks. Sham-operated and 17β-estradiol-treated OVX groups served as controls. Serum lipid levels—total cholesterol, triglycerides, LDL-C, and HDL-C—were assessed, and histological analysis of visceral adipose tissue was conducted to evaluate adipocyte morphology. Results: OVX-induced estrogen deficiency led to increased total cholesterol, triglycerides, and LDL-C, along with hypertrophic changes in visceral adipocytes. Supplementation with fermented Sargassum fulvellum (SfLlLm) markedly improved these parameters, reducing total cholesterol by 6.7%, triglycerides by 9.3%, and LDL-C by 52.9%, while increasing HDL-C by 17.5% compared to the OVX controls. SfLlLm also normalized visceral adipocyte size and distribution. These effects were comparable to or exceeded those of 17β-estradiol treatment. Conclusions: Fermented SfLlLm ameliorated dyslipidemia and visceral adiposity under estrogen-deficient conditions. These findings support its potential as a functional dietary intervention for managing postmenopausal lipid disorders and associated metabolic complications. Full article

This study investigated the effects of Lactococcus lactis subsp. 1.2472 (L)-, Streptococcus thermophilus 1.2718 (S)-, and thermostable Lactobacillus rhamnosus HCUL 1.1901-1912 (T)-fermented rice flour with inoculum levels of 3–11% (w/w) on rice bread staling. Optimal staling resistance was achieved, as follows: 9% L-fermented rice bread (LRB), 7% T-fermented rice bread (TRB), and 5% S-fermented rice bread (SRB). Lactic acid bacteria-fermented rice flour significantly enhanced hydration properties. LF-NMR analysis revealed that T₂₁ (strongly bound water) and T₂₂ (weakly bound water) relaxation times decreased, while T₂₃ (free water) increased with prolonged storage. Fermented-rice-flour groups had significantly more strongly bound water than the control group on 7 d. The optimized formulations exhibited exceptional volumetric stability with specific volume change rates of 17.63% (LRB), 17.60% (TRB), and 19.58% (SRB), coupled with maximal porosities of 10.34%, 9.05%, and 9.41%, respectively. This study provides a theoretical foundation for improving rice bread’s anti-staling properties. Full article

Background/Objectives: Lactobacillus kefiranofaciens HL1, isolated from kefir, exhibits antioxidant and anti-aging activities, defined here as improved cognitive function and reductions in oxidative stress and inflammatory markers. However, its poor milk viability limits application. This study developed a novel fermented milk by co-culturing HL1 with Lactococcus lactis subsp. cremoris APL015 (APL15) to enhance fermentation and health benefits. Methods: HL1 and APL15 were co-cultured to produce fermented milk (FM), and fermentation performance, microbial viability, texture, and syneresis were evaluated. A D-galactose-induced aging BALB/c mouse model was used to assess cognitive function, oxidative stress, inflammation, antioxidant enzyme activity, and gut microbiota after 8 weeks of oral administration. Results: FM reached pH 4.6 within 16 h, with high viable counts (~10⁹ CFU/mL) for both strains. HL1 viability and texture were maintained, with smooth consistency and low syneresis. In vivo, FM improved cognitive behavior (Y-maze, Morris water maze), reduced oxidative damage (MDA), lowered IL-1β and TNF-α, and enhanced brain SOD levels. FM-fed mice exhibited increased short-chain fatty acid producers, higher cecal butyrate, and reduced Clostridium perfringens. Conclusions: The co-cultured fermented milk effectively delivers HL1 and provides antioxidant, anti-inflammatory, and anti-aging effects in vivo, likely via gut–brain axis modulation. It shows promise as a functional food for healthy aging. Full article

Lactococcus lactis (L. lactis) is a pathogenic Gram-positive, catalase-negative coccobacillus (GPCN) associated with bovine mastitis. In this study, nine strains of L. lactis were successfully isolated and characterized from 457 milk samples from cows with clinical mastitis in China. All isolates exhibited a high degree of susceptibility to marbofloxacin and vancomycin. A series of molecular and cell biological techniques were used to explore the biological characteristics and pathogenicity of these isolates. The virulence gene profiles of the isolates were analyzed using whole genome resequencing combined with polymerase chain reaction (PCR) to elucidate the differences in virulence gene expression between isolates. To provide a more visual demonstration of the pathogenic effect of L. lactis on bovine mammary epithelial cells, an in vitro infection model was established using MAC-T cells. The results showed that L. lactis rapidly adhered to the surface of bovine mammary epithelial cells and significantly induced the release of lactate dehydrogenase, suggesting that the cell membranes might be damaged. Ultrastructural observations showed that L. lactis not only adhered to MAC-T cells, but also invaded the cells through a perforation mechanism, leading to a cascade of organelle damage, including mitochondrial swelling and ribosome detachment from the endoplasmic reticulum. The objective of this study was to provide strong evidence for the cytotoxic effects of L. lactis on bovine mammary epithelial cells. Based on this research, a prevention and treatment strategy for L. lactis as well as major pathogenic mastitis bacteria should be established, and there is a need for continuous monitoring. Full article

Background/Objectives: In this study, we aimed to evaluate probiotics’ clinical efficacy and safety in adults with chronic rhinosinusitis (CRS), and summarize mechanistic evidence related to mucosal immunity and microbiota modulation. Methods: We performed a systematic review and random-effects meta-analysis. MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Library were searched until May 2025. Eligibility: Randomized controlled trials (RCTs) and mechanistic studies investigating probiotics (any strain, dose, or administration route) in adults with CRS were eligible. Primary outcomes included changes in Sino-Nasal Outcome Test (SNOT-20/22) scores and CRS relapse rates. Secondary outcomes were adverse events and mechanistic endpoints. Results: Six studies (four RCTs, n = 337; two mechanistic studies) met the inclusion criteria. Probiotics did not significantly improve SNOT scores compared with the placebo, but trended in that direction (pooled mean difference—2.70; 95% CI −7.12 to 1.72; I² = 0%). Furthermore, probiotic use was associated with a non-significant trend towards fewer CRS relapses (risk ratio 0.41; 95% CI 0.16–1.04; p = 0.06; I² = 48%). Adverse events were mild and comparable to the placebo (risk ratio 0.87; 95% CI 0.33–2.34). Mechanistic data indicated that intranasal Lactococcus lactis W136 might downregulate type 1 inflammatory pathways and modestly increase microbiome diversity. Subgroup analyses (by route, duration, and CRS subtype) revealed no statistically significant effect modifiers, though mechanistic insights suggest possible differences in efficacy based on the CRS endotype and delivery method. Conclusions: Probiotics appear safe and may provide a small, non-significant improvement in CRS symptoms; emerging evidence of reduced relapse rates warrants further investigation through larger, endotype-stratified trials utilizing targeted probiotic strains and optimized delivery methods. Full article

The production of fermented sausages from poultry meat using traditional technologies and natural maturation conditions is a major challenge. The aim of this study was to identify indigenous microbiota with antilisterial activity from an innovative, additive-free, traditionally fermented chicken sausage. Isolates (n = 88) of lactic acid bacteria (LAB) were collected during maturation and subjected to MALDI-TOF mass spectrometry identification. The capacity to combat Listeria was screened against five strains using the agar well diffusion method in 63 selected LAB isolates. MALDI-TOF mass spectrometry identified four different LAB genera, namely Enterococcus, Lactococcus, Leuconostoc and Lactobacillus, the proportions of which differed significantly during the production phases (p < 0.001). Enterococcus faecalis was the most prevalent LAB species in the initial sausage dough. The presence of lactococci (Lactococcus lactis) and enterococci was detected during the 14- and 30-day ripening period and was gradually displaced by leuconostocs and lactobacilli. Lactobacilli appeared to be abundant during the central and late maturation phases, and consisted of only two species—Latilactobacillus sakei and Latilactobacillus curvatus. In total, 38 LAB isolates (60%) showed antilisterial activity toward at least one Listeria indicator strain. The proportions of antilisterial LAB differed significantly during sausage maturation. Inhibitory activity against all indicator Listeria was detected in the neutralized cell-free supernatants of five strains of Enterococcus faecalis, two L. sakei strains and one Leuconostoc mesenteroides strain. The antilisterial activity observed in the indigenous LAB revealed the possible role of L. sakei as a bioprotective culture, as well as the role of Ln. mesenteroides and E. faecalis as bacteriocin producers, for practical applications. Full article

The global antibiotic resistance crisis raises concerns about antibiotic use, and alternative strategies are urgently needed. In this context, host defense peptides (HDPs) have rapidly gained interest. However, one of the main obstacles is their production strategy. Chemical synthesis is the most widely used, although it is not scalable and has sequence limitations. A possible alternative is recombinant production, but the strategies used so far have limited efficiency. In this study, we aim to compare the activity and main characteristics of different HDPs produced by both chemical synthesis and by recombinant production, using an approach based on tetramers to ameliorate the production process. The results obtained showed that the production of HDPs as tetrameric peptides by recombinant production in Lactococcus lactis enhanced the peptide activity, with HDPs being much more active in terms of antimicrobial activity, more structurally stable, and nanostructured. Thus, the recombinant strategy described herein, fusing four repetitions of the same peptide, can become a real alternative to produce highly active HDPs through a scalable production process. Full article

Sixteen long-ripened, high-quality Cabrales cheeses from independent producers underwent a comprehensive biochemical and microbiological characterisation. Significant variations in total microbial counts and specific microbial groups were observed among the cheeses. A metataxonomic analysis identified 249 prokaryotic amplicon sequence variants (ASVs) and 99 eukaryotic ASVs, respectively, which were classified into 52 prokaryotic and 43 eukaryotic species. The predominant species included bacteria of the genera Tetragenococcus, Lactococcus (of which Lactococcus lactis was used as a starter), and Staphylococcus, followed by Brevibacterium and Corynebacterium species. The starter mould Penicillium roqueforti was highly abundant in all cheeses; Debaryomyces hansenii, Geotrichum candidum, and Kluyveromyces spp. constituted the subdominant fungal populations. Glutamic acid (≈20 mg g⁻¹) was the most abundant free amino acid in all samples, followed by lysine, leucine, and valine (≈10–13 mg g⁻¹). Moderate-to-high amounts of the biogenic amines tyramine and ornithine were detected. A large variation between cheeses of the main organic acids (lactic, acetic, or butyric) was detected. Differences between samples were also observed for the majority volatile compounds, which included organic acids, alcohols, esters, and ketones. Positive and negative correlations between bacterial and fungal species were detected, as well as between microbial populations and key biochemical markers. Among the latter, Tetragenococcus halophilus correlated positively with ethyl caprylate and hexanoic acid, and Loigolactobacillus rennini correlated positively with γ-aminobutyric acid. Conversely, Staphylococcus equorum showed a strong negative correlation with ethyl caprylate and capric acid. These microbial and biochemical insights enabled us to propose a microbiota-based starter culture comprising prokaryotic and eukaryotic components to enhance Cabrales cheese quality. Full article

Microfluidic platforms have emerged as critical technologies for exploring sperm chemotaxis, providing precise gradient control, and facilitating in-depth behavioral assessment. We designed a novel, user-friendly microfluidic device that is optimized for human sperm morphology and motility. The device was validated using two well-established sperm chemoattractants, progesterone and bourgeonal, demonstrating its reliability and reproducibility. Given the key role of olfactory receptors (ORs) in mediating sperm chemotaxis, the newly developed device was employed to identify additional receptors that may contribute to sperm behavior. Using the Atlas database, we identified OR2H1 as a candidate receptor. It is enriched in testis-derived cells, particularly in early and late spermatids, and it is broadly expressed across human spermatozoa. We demonstrated that OR2H1’s ligand, methional, a sulfur-containing aldehyde naturally found in vaginal fluid and biosynthesized by Lactococcus lactis, significantly enhances sperm migration and progressive motility. Methional stimulation also triggered increased intracellular calcium levels, indicating receptor activation. Computer-assisted sperm analysis revealed that methional treatment improved sperm linearity, straightness, and wobble without affecting the average velocity, suggesting enhanced directional movement. These findings provide evidence that methional promotes sperm chemotaxis via OR2H1 and highlight the potential role of the vaginal microbiome in influencing human fertility. Full article

Raw goat milk-derived Lactococcus lactis MK1/3 (CCM 9209) was studied to show its potential for use in the dairy industry. Finding an innovative strain indicates having a new safe, original additive for functional food. The strain has been shown to be safe using a model experiment with Balb/c mice, when no mortality was noted. Its counts were increased continually during 120 days, with the highest value on day 90 (4.38 ± 1.24 colony-forming unit per gram (CFU/g, log 10). In vivo (in the experimental mice), anti-staphylococcal effect was noted with difference 1.82 log cycles. The safety of the strain MK1/3 has been also indicated by the fact that it did not produce damaging enzymes, it has been susceptible to antibiotics, and it has shown low-grade biofilm-forming ability (0.126 ± 0.35). This strain has tolerated bile, and low pH sufficiently. It produced a postbiotic active substance with inhibitory activity against cheese and milk contaminants (Enterococci), reaching antimicrobial activity up to 3200 AU/mL. The count of the strain MK1/3 was higher in yogurts from ewe goat milk (4.66 ± 0.30 CFU/g, log 10), in comparison with its count in yogurts from ewe milk (4.10 ± 0.10 CFU/g, log 10), with no influencing yogurt pH. Its use in 100% starter culture to process fresh cheese based on goat milk was revealed in the standard cheese quality with sufficient amount of lactic acid microbiota. To support the benefit of the strain MK1/3, additional human trials have been reinforced. Full article

The health benefits associated with microbial species inhabiting aquatic animals have garnered increasing attention, as it is expected that the colonization and efficacy of native probiotic bacteria adapted to the internal environment of the target species will be more active than non-native bacteria. In this study, six isolates were obtained from the intestinal tract of largemouth bass. Three of these isolates demonstrated higher growth ability compared to the others and were further characterized using in vitro assays. Lactococcus lactis LBM15 was found to exhibit antibacterial activity against common pathogens affecting largemouth bass; the adhesion inhibition capabilities of the isolates were systematically evaluated through competitive, repulsive, and substitutive adhesion assays. The strain inhibited adhesion to all six tested pathogen strains, with competitive adhesion inhibition rates ranging from 42% to 54%, the highest of which was observed against V. anguillarum. Repulsive adhesion inhibition rates ranged from 27% to 55%, with the highest rate noted for Edwardsiella tarda. Additionally, substitutive adhesion inhibition rates were found to range from 48% to 76%, with the highest inhibition observed against Aeromonas hydrophila. Furthermore, LBM15 exhibited favorable antimicrobial susceptibility profiles, showing sensitivity to 21 antibiotics tested. Notably, safety assessment trials were performed exposing fish to LBM15 at a concentration of 1 × 10⁹ CFU/mL by injection and at a concentration of 1 × 10⁸ CFU/mL by feed administration. No clinical abnormalities, behavioral alterations, or mortality were documented in either exposure group, confirming the safety of LBM15 for application in aquaculture. The results suggested that LBM15 isolates from largemouth bass have potential for further investigation and possible application as probiotic candidates. Full article

The increasing interest in fermented foods stems from their health benefits, mediated by foodborne microorganisms. This study aimed to characterize the fermentative microbiota of Pecorino di Picinisco, a traditional Italian cheese made from ovine raw milk, and to evaluate the probiotic and technological potential of selected lactic acid bacteria strains. Three strains representative of the different species found (Lactococcus lactis, Lactiplantibacillus plantarum and Latilactobacillus curvatus) were chosen and analyzed. All three strains were able to adhere to human intestinal Caco-2 cells, were resistant to simulated in vitro digestion and significantly prolonged the lifespan of Caenorhabditis elegans, used as a simplified in vivo model, with respect to the commercial probiotic strain Lacticaseibacillus rhamnosus GG. The L. plantarum Pic37.4 strain was particularly promising; therefore, its cell-free supernatant was employed to evaluate the antimicrobial activity against indicator strains of foodborne and intestinal pathogens or spoilage bacteria. The results demonstrated the effectiveness of the supernatant against all strains tested, with the strongest effect on the intestinal pathogen enterotoxigenic Escherichia coli K88. In addition, the inhibitory effect on pathogen adhesion to intestinal mucosa was investigated on Caco-2 cells, resulting in a significant reduction in adhesion mediated by the L. plantarum Pic37.4 supernatant. The antimicrobial properties of the L. plantarum strain were confirmed in vivo in C. elegans. These promising results lay the ground for further investigations aimed at substantiating the probiotic and technological potential of the L. plantarum Pic37.4 investigated in this work. Full article

Hyperuricemia (HUA) is a metabolic disorder characterized by excessive uric acid (UA) production and impaired excretion. Goji, as a representative medicinal food, holds significant research and development value, while probiotic fermentation technology is finding increasingly widespread applications in the functional food sector. This study developed a novel goji fermented with three probiotic strains (Lactoplantibacillus plantarum CGMCC8198, Lactococcus lactis LTJ28, and Lactocaseibacillus casei YR2-2) and investigated its anti-HUA effects. Optimal fermentation conditions (7.913 material–liquid ratio, 3.92% inoculation, 7.49 h at 37 °C with 1:1:2 strain ratio) yielded a beverage with enhanced flavor profiles (19 aroma compounds) and high viable counts. In HUA cell models, the 15% fermented goji juice significantly reduced UA levels by 56% (p < 0.01). In potassium oxonate-induced HUA mice, the beverage effectively lowered serum UA, xanthine oxidase activity, and renal function markers (blood urea nitrogen and creatinine, p < 0.0001) while improving hepatic parameters (alanine aminotransferase, aspartate Aminotransferase). The goji-fermented juice significantly reduced the expression of renal UA transporters GLUT9 and URAT1 (p < 0.0001) while improving gut microbiota composition, as evidenced by increased beneficial SCFAs (acetic acid, butyric acid, p < 0.0001) and elevated Lactobacillus abundance 2.14-fold. Our findings demonstrate that this triple-probiotic-fermented goji beverage represents an effective dietary strategy for HUA management by simultaneously inhibiting UA production, enhancing excretion, and restoring gut microbiota homeostasis, providing a scientific basis for developing probiotic-based functional foods against HUA. Full article

Background/Objectives: The number of chronic kidney disease (CKD) patients is increasing in Japan, and this population is at high risk of death from cardiovascular and cerebrovascular diseases. Therefore, prevention of arteriosclerosis as a common underlying cause of these diseases is required. In this study, we examined whether 11/19-B1 yogurt, which has been proven to reduce serum low-density lipoprotein (LDL) levels, can decrease the serum levels of indoxylsulfate and trimethylamine-N-oxide (TMAO), which are produced by intestinal microbiota and known to cause arteriosclerosis, through improving dysbiosis in hemodialysis patients. Methods: Nineteen dialysis patients consumed 50 g of 11/19-B1 yogurt daily for 8 weeks, and changes in serum lipid profile and uremic toxin levels, intestinal microbiome, as well as the frequency of bowel movement and stool characteristics were observed. Results: The results demonstrated that an intake of yogurt decreased serum LDL 99.3 to 88.5 (p = 0.049) and indoxylsulfate in seven of nine subjects with previously high concentrations, and improved stool characteristics as estimated by the Bristle stool score, although decreased HDL and no beneficial effect on serum TMAO was observed. Conclusions: These results may suggest that the ingestion of 11/19-B1 yogurt provides a preventative effect against the progression of atherosclerosis and renal dysfunction. Full article

Background/Objectives: Listeria monocytogenes is a major foodborne pathogen responsible for listeriosis, a serious illness with high morbidity and mortality, particularly in vulnerable populations. Its persistence in food processing environments and resistance to conventional preservation methods pose significant food safety challenges. Lactic acid bacteria (LAB) offer a promising natural alternative due to their antimicrobial properties, especially through the production of bacteriocins. This study investigates the competitive interactions between Lactococcus lactis and L. monocytogenes under co-culture conditions, with a focus on changes in their secretomes to better understand how LAB-derived bacteriocins can help mitigate the Listeria burden. Methods: Proteomic approaches, including Tricine-SDS-PAGE, two-dimensional electrophoresis, and shotgun proteomics, were employed to analyze the molecular adaptations of both species in response to bacterial competition. Results: Our results reveal a significant increase in the secretion of enolase by L. monocytogenes when in competition with L. lactis, suggesting its role as a stress-responsive moonlighting protein involved in adhesion, immune evasion, and biofilm formation. Concurrently, L. lactis exhibited a shift in the production of its bacteriocin, nisin, favoring the expression of Nisin Z—a variant with improved solubility and diffusion properties. This differential regulation indicates that bacteriocin production is modulated by bacterial competition, likely as a defensive response to the presence of pathogens. Conclusions: These findings highlight the dynamic interplay between LAB and L. monocytogenes, underscoring the potential of LAB-derived bacteriocins as natural biopreservatives. Understanding the molecular mechanisms underlying microbial competition could enhance food safety strategies, particularly in dairy products, by reducing reliance on chemical preservatives and mitigating the risk of L. monocytogenes contamination. Full article