Gut Microbiota-Mediated Immunomodulatory Effects of Lactobacillus rhamnosus HDB1258 Cultured in the Lava Seawater in the Colitis Mouse Model.

The immunomodulatory effects of Lactobacillus rhamnosus HDB1258 were evaluated in mice with colitis induced by Klebsiella oxytoca (KO). L. rhamnosus HDB1258 was cultured in the lava seawater (LS) to improve its probiotic properties. It increased adhesive ability to mucin with mRNA expression levels of chaperone proteins (such as GroEL/ES, DnaKJ, and HtrA). In the in vivo experiments, administration of KO caused an inflammation on the colon with gut dysbiosis. LH group (oral gavage of HDB1258 1.0 × 109 colony forming units/day) showed that inflammatory biomarkers, including IL-1ß, TNF-α, IL-6, and PGE2, were significantly decreased to less than half of the KO group, and Th1 cells were decreased in the spleen, but Treg cells were not affected. In contrast, the expression levels of secretory IgA and IL-10 were significantly increased, and the composition of gut microbiota in the LH group tended to recover similar to normal mice without any effect on the α-diversity. In conclusion, L. rhamnosus HDB1258 cultured in the LS could regulate competitively pathogenic bacteria in imbalanced flora with its improved mucin adhesive ability and was an effective immunomodulatory adjuvant for treating colitis by its regulatory function on intestinal inflammation.

Lactobacillus rhamnosus HDB1258 modulates gut microbiota-mediated immune response in mice with or without lipopolysaccharide-induced systemic inflammation.

BACKGROUND: Gut microbiota closely communicate in the immune system to maintain a balanced immune homeostasis in the gastrointestinal tract of the host. Oral administration of probiotics modulates gut microbiota composition. In the present study, we isolated Lactobacillus rhamnosus HDB1258, which induced tumor necrosis factor (TNF)-α and interleukin (IL)-10 expression in macrophages, from the feces of breastfeeding infants and examined how HDB1258 could regulate the homeostatic immune response in mice with or without lipopolysaccharide (LPS)-induced systemic inflammation. RESULTS: Oral administration of HDB1258 significantly increased splenic NK cell cytotoxicity, peritoneal macrophage phagocytosis, splenic and colonic TNF-α expression, TNF-α to IL-10 expression ratio, and fecal IgA level in control mice, while Th1 and Treg cell differentiation was not affected in the spleen. However, HDB1258 treatment significantly suppressed peritoneal macrophage phagocytosis and blood prostaglandin E2 level in mice with LPS-induced systemic inflammation. Its treatment increased LPS-suppressed ratios of Treg to Th1 cell population, Foxp3 to T-bet expression, and IL-10 to TNF-α expression. Oral administration of HDB1258 significantly decreased LPS-induced colon shortening, myeloperoxidase activity and NF-κB+/CD11c+ cell population in the colon, while the ratio of IL-10 to TNF-α expression increased. Moreover, HDB1258 treatment shifted gut microbiota composition in mice with and without LPS-induced systemic inflammation: it increased the Cyanobacteria and PAC000664_g (belonging to Bacteroidetes) populations and reduced Deferribacteres and EU622763_s group (belonging to Bacteroidetes) populations. In particular, PAC001066_g and PAC001072_s populations were negatively correlated with the ratio of IL-10 to TNF-α expression in the colon, while the PAC001070_s group population was positively correlated. CONCLUSIONS: Oral administered HDB1258 may enhance the immune response by activating innate immunity including to macrophage phagocytosis and NK cell cytotoxicity in the healthy host and suppress systemic inflammation in the host with inflammation by the modulation of gut microbiota and IL-10 to TNF-α expression ratio in immune cells.

Probiotic properties of novel probiotic Levilactobacillus brevis KU15147 isolated from radish kimchi and its antioxidant and immune-enhancing activities.

This study was conducted to evaluate the probiotic properties and antioxidant activities of lactic acid bacteria strains including Levilactobacillus brevis KU15147 isolated from kimchi to determine their potential as a probiotic. The tolerance of all strains to gastric acid and bile salts was more than 90%. The strains did not produce a ß-glucuronidase and survived following treatment with gentamicin, kanamycin, streptomycin, and ciprofloxacin. L. brevis KU15147 showed greater adhesion activity to HT-29 cells (6.38%) and its antioxidant activities were higher than those of other tested strains, showing values of 38.56%, 22%, and 23.82% in DPPH, ABTS, and ß-carotene bleaching assays, respectively. Additionally, the relative expression intensities of induced nitric oxide synthase and tumor necrosis factor-α of L. brevis KU15147 were greater than those of other strains, suggesting that this strain can be applied in the health food or pharmaceutical industry as a novel probiotic strain.

Probiotic Properties and Antioxidant Activities of Pediococcus pentosaceus SC28 and Levilactobacillus brevis KU15151 in Fermented Black Gamju.

Black gamju is Korean traditional beverage fermented with molds. The aim of this study was to assess the probiotic properties and antioxidant activities of novel Pediococcus pentosaceus SC28 and Levilactobacillus brevis KU15151 to develop black gamju with bioactive properties for health. Tolerance against artificial gastric juice and bile salts, adhesion ability on HT-29 cells of strains, and antibiotics susceptibility were evaluated as probiotics, and various enzyme productions were detected. The 2,2-diphenyl-1-picrylhydrazyl assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate, and ß-carotene bleaching assay were used for antioxidant activity of samples. The tolerance of both strains to artificial gastric juice and bile salts (Oxgall) was more than 90%. Additionally, both strains did not produce ß-glucuronidase and were resistant to gentamicin, kanamycin, streptomycin, and ciprofloxacin. After fermentation of black gamju with each strain, the number of viable lactic acid bacteria increased to 8.25-8.95 log colony forming unit/mL, but the pH value of fermented samples decreased more (to pH 3.33-3.41) than that of control (pH 4.37). L. brevis KU15151 showed higher adhesion activity to HT-29 cells and antioxidant effects than P. pentosaceus SC28 in three antioxidant assays.

Probiotic Properties of Lactobacillus brevis KU200019 and Synergistic Activity with Fructooligosaccharides in Antagonistic Activity against Foodborne Pathogens.

This study aims to evaluate the probiotic properties of Lactobacillus brevis (L. brevis) KU200019 and the synergistic activity with prebiotics on antimicrobial activity, and the potential application as an adjunct culture in fermented dairy products. The commercial strain, L. brevis ATCC 14869 was used as reference strain. L. brevis KU200019 was showed higher viability in simulated gastric (99.38±0.21%) and bile (115.10±0.13%) conditions compared to reference strain. L. brevis KU200019 exhibited antimicrobial activity against various foodborne pathogens. The supplementation of fructooligosaccharides (FOS) enhanced viability of lactic acid bacteria (>8 Log CFU/mL) and antioxidant activity [2,2-diphenyl-2-picrylhydrazyl radical assay (DPPH) assay, 31.23±1.14%; 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay, 38.82±1.46%] in fermented skim milk during refrigerated storage. L. brevis KU200019 was distinguished from the reference strain by its higher probiotic potential, antimicrobial activity, and higher antioxidant activity in fermented milk. Therefore, L. brevis KU200019 with FOS was demonstrated promising properties for further application in fermented dairy products with enhanced safety and quality.

Antioxidant and immune-enhancing effects of probiotic Lactobacillus plantarum 200655 isolated from kimchi.

Probiotic properties including antioxidant and immune-enhancing effects of Lactobacillus plantarum 200655 isolated from kimchi were evaluated. The tolerance of three strains (L. plantarum 200655, L. plantarum KCTC 3108, and L. rhamnosus GG to bile salts (0.3% oxgall, 24 h) was similar, and L. plantarum 200655 showed the highest tolerance to gastric juice (0.3% pepsin, 3 h). All strains presented similar autoaggregation ability. L. plantarum 200655 showed higher cell surface hydrophobicity and adhesion ability on HT-29 cells. L. plantarum 200655 did not produce ß-glucuronidase and was sensitive to ampicillin, tetracycline, chloramphenicol, and doxycycline. Additionally, L. plantarum 200655 showed the highest antioxidant effects in DPPH and ABTS radical scavenging, and ß-carotene bleaching assays. RAW 264.7 cells treated with L. plantarum 200655 produced more nitric oxide, induced nitric oxide synthase, and cytokine related to immune-enhancing effects such as interleukin-1ß and interleukin-6. Therefore, L. plantarum 200655 could be useful as a probiotic strain for older people.

Antioxidant and immunostimulatory effect of potential probiotic Lactobacillus paraplantarum SC61 isolated from Korean traditional fermented food, jangajji.

This study aimed to isolate and demonstrate their antioxidant and immunostimulatory activities of potential probiotics. The isolated strains, S. Pum19, SC28, and SC61 showed potential probiotic properties including stability in artificial gastric and bile conditions, non-production of ß-glucuronidase, suitable antibiotic susceptibility, and attachment to intestinal cells. S. Pum19, SC28, and SC61 strains were identified as Leuconostoc citreum, Pediococcus pentosaceus, and Lactobacillus paraplantarum, respectively. Of the 3 potential probiotic LAB strains, intact cells of L. paraplantarum SC61 showed higher antioxidant activity, including DPPH radical scavenging, ß-carotene bleaching inhibition, reducing power, superoxide anion scavenging, and ABTS radical scavenging activity. In addition, L. paraplantarum SC61 produced the most nitric oxide production and its mRNA expression level for iNOS, IL-1ß, IL-6, and TNF-α were superior to those of L. rhamnosus GG. Therefore, L. paraplantarum SC61 was demonstrated to exhibit antioxidant and immunostimulatory activity and to have potential use as a probiotic product.

Probiotic lactic acid bacteria isolated from traditional Korean fermented foods based on ß-glucosidase activity.

This study was designed to isolate lactic acid bacteria (LAB) with ß-glucosidase activity and probiotic properties from Korean fermented foods. Among nine isolates, four LAB strains had excellent survival rates at pH 2.5 with 0.3% (w/v) pepsin for 3 h and 0.3% (w/v) oxgall for 24 h. Four LAB strains did not produce ß-glucuronidase and showed adhesion ability to HT-29 cells that was superior to that shown by the reference strain Lactobacillus rhamnosus GG. All four strains were sensitive to ampicillin, tetracycline, chloramphenicol, and doxycycline. These strains were identified as Leuconostoc mesenteroides H40, Lactobacillus plantarum FI10604, L. brevis FI10700, and L. perolens FI10842 by 16S rRNA gene sequence, respectively. It was found that L. perolens FI10842 produced the highest ß-glucosidase activity (49.10 mU/mL). These results indicate that the four LAB strains could be used as potential probiotic. Especially L. perolens FI10842 could be used as a starter culture for fermentation.

In vitro characterization of Lactobacillus brevis KU15006, an isolate from kimchi, reveals anti-adhesion activity against foodborne pathogens and antidiabetic properties.

This study aimed at evaluating the functional and probiotic properties of three lactic acid bacterial (LAB) strains isolated from kimchi. The selected LAB strains, which had potential probiotic functions, were identified by 16S rRNA sequence analysis as Lactobacillus brevis G1, L. brevis KU15006, and Lactobacillus curvatus KCCM 200173. All LAB strains were able to tolerate incubation at pH 2.5 with 0.3% pepsin for 3 h and with 0.3% Oxgall for 24 h and showed similar enzyme production levels, antimicrobial activities, and antibiotic susceptibilities. L. brevis G1 and KU15006 presented higher adhesion ability, auto-aggregation, and cell surface hydrophobicity than Lactobacillus rhamnosus KCTC 12202BP, a commercial strain used as positive control. All LAB strains showed 50-60% co-aggregation activity with selected foodborne pathogens. L. brevis KU15006 showed anti-adhesion activity against Escherichia coli and Salmonella Typhimurium. In addition, cell-free supernatant and cell-free extract from L. brevis KU15006 displayed the highest inhibitory activities against α-glucosidase. These results indicate that L. brevis KU15006 has the best properties, with pathogen antagonistic and antidiabetic activity, for use in probiotic products.

Probiotic characterization of Bacillus subtilis P223 isolated from kimchi.

Probiotic characteristics of Bacillus subtilis P223 isolated from kimchi were investigated in this study. Spore cells of B. subtilis P223 showed high tolerance to artificial gastric juice (pH 2.5, 0.3% pepsin, 3 h) and bile salts (0.3% oxgall, 24 h). Spore cells of B. subtilis P223 showed more adherence to intestinal cells (HT-29 cells) than vegetative cells. In addition, B. subtilis P223 showed high autoaggregation ability, similar to a commercial strain (Bacillus clausii ATCC 700160). Moreover, its coaggregation abilities with pathogens were strong. The adherence of three pathogens (Salmonella enteritidis ATCC 13076, Listeria monocytogenes ATCC 15313, and Escherichia coli ATCC 25922) to HT-29 cells was inhibited by B. subtilis P223. It was found that B. subtilis P223 could not produce ß-glucuronidase, a carcinogenic enzyme. However, it had amylase and protease activities. Antibiotic susceptibility was measured using disk diffusion assay. It was revealed that B. subtilis P223 was only resistant to streptomycin among eight kinds of antibiotics. In addition, B. subtilis P223 showed no hemolysis activity. It did not have enterotoxin genes. Results of this study suggest that B. subtilis P223 isolated from kimchi has potential as a probiotic strain.