Safety Assessment of Levilactobacillus brevis KU15006: A Comprehensive Analysis of its Phenotypic and Genotypic Properties.

Levilactobacillus brevis KU15006, isolated from kimchi, exhibits pathogen-antagonistic and anti-diabetic activities; however, the safety of this strain has not been assessed. In the present study, L. brevis KU15006 was evaluated to elucidate its safety as a probiotic strain using phenotypic and genotypic analyses. Its safety was assessed using a minimum inhibitory concentration test comprising nine antibiotics, 26 antibiotic resistance genes, a single conjugative element, virulence gene analysis, hemolysis, cell cytotoxicity, mucin degradation, and toxic metabolite production. L. brevis KU15006 exhibited equal or lower minimum inhibitory concentration for the nine antibiotics than the cut-off value established by the European Food Safety Authority. It did not harbor antibiotic resistance and virulence genes. L. brevis KU15006 lacked ß-hemolysis, mucin degradation, cytotoxicity against Caco-2 cells, gelatin liquefaction, bile salt deconjugation, and toxic metabolite production abilities. Based on the results, L. brevis KU15006, which has antagonistic and anti-diabetic effects, could be marketed as a probiotic in the future.

A2 milk consumption and its health benefits: an update.

Milk is a widely consumed nutrient-rich food containing protein variants such as casein A2 and A1. A1 differs from A2 in an amino acid at position 67 (Pro67 to His67). The breakdown of ß-casein yields ß-casomorphins (BCM), among which BCM-7 is extensively studied for its effects on the human body. Animal studies have shown that A1 ß-casein milk increases digestive transit time and enhances myeloperoxidase activity. Individuals with lactose intolerance prefer A2 milk to conventional A1 milk, as BCM-7 in A1 milk can lead to inflammation and discomfort in sensitive individuals. A2 milk, which contains A2 ß-casein, is believed to be more easily digestible than A1 ß-casein. Its popularity has grown owing to reports linking A1 casein to diseases such as type 1 diabetes, heart disease, and autism. A2 milk has gained popularity as an alternative to A1 milk, primarily because of its potential benefits for individuals with certain diseases. This review aims to provide an updated understanding of A2 milk consumption and its health benefits. This review aims to provide an updated understanding of A2 milk consumption and its health benefits.

Assessing the Anti-Obesity Potential of Lactococcus lactis subsp. lactis CAB701: Modulation of Adipocyte Differentiation and Lipid Metabolism in In Vitro and In Vivo Models.

In this study, the potential anti-obesity effects of Lactococcus lactis subsp. lactis CAB701, a probiotic strain isolated from cabbage, were investigated using in vitro and in vivo assays. L. lactis subsp. lactis CAB701 inhibited adipocyte differentiation of 3T3-L1 cells by 67%. In an in vivo model of high-fat diet-induced obese mice, treatment with L. lactis subsp. lactis CAB701 markedly reduced body weight and peri-epididymal fat mass, and significantly reduced serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels. Molecular analysis revealed a significant modulation of key genes and proteins involved in lipid metabolism and adipogenesis. Specifically, fatty acid synthase and peroxisome proliferator-activated receptor gamma were significantly downregulated in peri-epididymal adipose tissue, alluding to the molecular mechanism underlying the anti-obesity effects exerted by L. lactis subsp. lactis CAB701. Furthermore, histological examination revealed a significant reduction in adipocyte size in the treated group, indicating effective adipose tissue remodeling. Our findings suggest that L. lactis subsp. lactis CAB701 mediates anti-obesity effects through the modulation of critical molecular markers and lipid profiles. L. lactis subsp. lactis CAB701 thus represents a promising candidate for combating obesity and related metabolic disorders.

Immunostimulatory Activity of Lactococcus lactis subsp. lactis CAB701 Isolated from Jeju Cabbage.

This study explored the potential of Lactococcus lactis subsp. lactis CAB701 as a probiotic strain, focusing on its immunostimulatory properties. Despite adverse conditions in the gastrointestinal environment, this strain exhibited remarkable survivability, as evidenced by its tolerance to acid, bile, and pancreatin, coupled with its impressive ability to adhere to Caco-2 cells. It also exhibited significant antioxidant activity, similar to the established probiotic Lacticaseibacillus rhamnosus GG (LGG). Our research elucidates the potent immunostimulatory effects of L. lactis subsp. lactis CAB701. This strain significantly enhanced nitric oxide production in RAW 264.7, far exceeding that obtained with LGG. An in-depth examination revealed elevated expression of key inflammatory mediators, including inducible nitric oxide synthase, tumor necrosis factor-alpha, cyclooxygenase-2, interleukin (IL)-1 beta, and IL-6. L. lactis subsp. lactis CAB701 increases the expression of critical signaling proteins in the mitogen-activated protein kinase pathway. This prompted a substantial increase in the expression of phosphorylated c-Jun N-terminal kinases and extracellular signal-regulated kinases, suggesting their role in modulating these immune-related pathways. Overall, these findings demonstrate the significant immunostimulatory capacity of L. lactis subsp. lactis CAB701, positioning it as a potential candidate for probiotic use, especially in applications that enhance immune responses.

The Radical Scavenging Activities and Anti-Wrinkle Effects of Soymilk Fractions Fermented with Lacticaseibacillus paracasei MK1 and Their Derived Peptides.

Soybean-derived peptides exert several beneficial effects in various experimental models. However, only a few studies have focused on the radical scavenging and anti-wrinkle effects of soymilk-derived peptides produced via different processes, such as fermentation, enzymatic treatment, and ultrafiltration. Therefore, in this study, we investigated the radical scavenging and antiwrinkle effects of soymilk fractions produced using these processes. We found that 50SFMKUF5, a 5 kDa ultrafiltration fraction fermented with Lacticaseibacillus paracasei MK1 after flavourzyme treatment, exhibited the highest radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay as well as potent anti-wrinkle effects assessed by type 1 procollagen production and tumor necrosis factor-α production in ultraviolet B (UVB)-treated human dermal fibroblasts and HaCaT keratinocytes. To identify potential bioactive peptides, candidate peptides were synthesized, and their anti-wrinkle effects were assessed. APEFLKEAFGVN (APE), palmitoyl-APE, and QIVTVEGGLSVISPK peptides were synthesized and used to treat UVB-irradiated fibroblasts, HaCaT keratinocytes, and α-melanocyte-stimulating hormone-induced B16F1 melanoma cells. Among these peptides, Pal-APE exerted the strongest effect. Our results highlight the potential of soymilk peptides as anti-aging substances.

Synergistic Immunostimulatory Activities of Probiotic Strains, Leuconostoc lactis and Weissella cibaria, and the Prebiotic Oligosaccharides They Produce.

Synbiotics contain health-beneficial bacteria, i.e., probiotics and prebiotics selectively utilized by the probiotics. Herein, three probiotic strains, Leuconostoc lactis CCK940, L. lactis SBC001, and Weissella cibaria YRK005, and the oligosaccharides produced by these strains (CCK, SBC, and YRK, respectively) were used to prepare nine synbiotic combinations. Macrophages (RAW 264.7) were treated with these synbiotic combinations and the corresponding lactic acid bacteria and oligosaccharides alone to evaluate the treatments' immunostimulatory activities. The level of nitric oxide (NO) production was significantly higher in the macrophages treated with the synbiotics than in those treated with the corresponding probiotic strains and the oligosaccharide alone. The immunostimulatory activities of the synbiotics increased regardless of the probiotic strain and the type of oligosaccharide used. The expressions of tissue necrosis factor-α, interleukin-1ß, cyclooxygenase-2, inducible NO synthase genes, and extracellular-signal-regulated and c-Jun N-terminal kinases were significantly higher in the macrophages treated with the three synbiotics than in those treated with the corresponding strains or with the oligosaccharides alone. These results indicate that the synergistic immunostimulatory activities of probiotics and the prebiotics they produced in the studied synbiotic preparations resulted from the activation of the mitogen-activated protein-kinase-signaling pathway. This study suggests the combined use of these probiotics and prebiotics in the development of synbiotic preparations as health supplements.

Structural analysis and prebiotic activity of exopolysaccharide produced by probiotic strain Bifidobacterium bifidum EPS DA-LAIM.

Exopolysaccharide (EPS)-producing Bifidobacterium bifidum EPS DA-LAIM was isolated from healthy human feces, the structure of purified EPS from the strain was analyzed, and its prebiotic activity was evaluated. The EPS from B. bifidum EPS DA-LAIM is a glucomannan-type heteropolysaccharide with a molecular weight of 407-1007 kDa, and its structure comprises 2-mannosyl, 6-mannosyl, and 2,6-mannosyl residues. The purified EPS promoted the growth of representative lactic acid bacteria and bifidobacterial strains. Bifidobacterium bifidum EPS DA-LAIM increased nitric oxide production in RAW 264.7 macrophage cells, indicating its immunostimulatory activity. Bifidobacterium bifidum EPS DA-LAIM also exhibited high gastrointestinal tract tolerance, gut adhesion ability, and antioxidant activity. These results suggest that EPS from B. bifidum EPS DA-LAIM is a potentially useful prebiotic material, and B. bifidum EPS DA-LAIM could be applied as a probiotic candidate. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01213-w.