Kang Oh Lee

Lactic acid bacteria affect serum cholesterol levels, harmful fecal enzyme activity, and fecal water content.

BackgroundLactic acid bacteria (LAB) are beneficial probiotic organisms that contribute to improved nutrition, microbial balance, and immuno-enhancement of the intestinal tract, as well as lower cholesterol. Although present in many foods, most trials have been in spreads or dairy products. Here we tested whether Bifidobacteria isolates could lower cholesterol, inhibit harmful enzyme activities, and control fecal water content.MethodsIn vitro culture experiments were performed to evaluate the ability of Bifidobacterium spp. isolated from healthy Koreans (20~30 years old) to reduce cholesterol-levels in MRS broth containing polyoxyethanylcholesterol sebacate. Animal experiments were performed to investigate the effects on lowering cholesterol, inhibiting harmful enzyme activities, and controlling fecal water content. For animal studies, 0.2 ml of the selected strain cultures (108~109 CFU/ml) were orally administered to SD rats (fed a high-cholesterol diet) every day for 2 weeks.ResultsB. longum SPM1207 reduced serum total cholesterol and LDL levels significantly (p < 0.05), and slightly increased serum HDL. B. longum SPM1207 also increased fecal LAB levels and fecal water content, and reduced body weight and harmful intestinal enzyme activities.ConclusionDaily consumption of B. longum SPM1207 can help in managing mild to moderate hypercholesterolemia, with potential to improve human health by helping to prevent colon cancer and constipation.

Efficacy of Lactic Acid Bacteria (LAB) supplement in management of constipation among nursing home residents

BackgroundConstipation is a significant problem in the elderly, specifically nursing home and/or extended-care facility residents are reported to suffer from constipation. Lactic acid bacteria (LAB) are beneficial probiotic organisms that contribute to improved nutrition, microbial balance, and immuno-enhancement of the intestinal tract, as well as diarrhea and constipation effect. The objective of this study was to investigate the efficacy of this LAB supplement in the management of nursing home residents.MethodsNineteen subjects (8M, 11F; mean age 77.1 ± 10.1) suffering with chronic constipation were assigned to receive LAB (3.0 × 1011 CFU/g) twice (to be taken 30 minutes after breakfast and dinner) a day for 2 weeks in November 2008. Subjects draw up a questionnaire on defecation habits (frequency of defecation, amount and state of stool), and we collected fecal samples from the subjects both before entering and after ending the trial, to investigate LAB levels and inhibition of harmful enzyme activities. Results were tested with SAS and Students t-test.ResultsAnalysis of questionnaire showed that there was an increase in the frequency of defecation and amount of stool excreted in defecation habit after LAB treatment, but there were no significant changes. And it also affects the intestinal environment, through significantly increase (p < 0.05) fecal LAB levels. In addition, tryptophanase and urease among harmful enzyme activities of intestinal microflora were significantly decreased (p < 0.05) after LAB treatment.ConclusionLAB, when added to the standard treatment regimen for nursing home residents with chronic constipation, increased defecation habit such as frequency of defecation, amount and state of stool. So, it may be used as functional probiotics to improve human health by helping to prevent constipation.

Hypocholesterolemic effect of sonication-killed Bifidobacterium longum isolated from healthy adult Koreans in high cholesterol fed rats

We have previously reported that live Bifidobacterium longum SPM1207, a strain isolated from healthy adult Koreans, significantly reduced serum cholesterol in broth and rat. We here examined the effect of oral administration of sonication-killed B. longum SPM1207 on serum cholesterol in rats in order to investigate whether this killed strain could be utilized as a potent probiotics for human and animals. Dietary treatments consisted of 3 treatment groups of 24 rats each randomly assigned to either normal diet, high cholesterol diet and saline (HCS), or high cholesterol diet and sonication-killed B. longum SPM1207 (HCKB) for 3 weeks. Although HDL-cholesterol levels in the serum were not significantly (p > 0.05) different between HCKB rats and HCS rats, total and LDL-cholesterol levels in the serum were significantly (p < 0.05) less increased in HCKB (total: 177.71 mg/dL, LDL-: 60.50 mg/dL) rats when compared to HCS (total: 237.17 mg/dL, LDL-: 71.50 mg/dL) rats. AI was significantly (p < 0.05) lower in HCKB (4.95 mg/dL) rats when compared to HCS (9.22 mg/dL) rats. Body weight increase and relative liver weight were significantly (p < 0.05) lower in HCKB rats when compared to HCS rats. Over the time, high cholesterol diet caused dry feces accompanied by decreased fecal water content (66.00 to 61.94%) but sonication-killed B. longum SPM1207 administration increased fecal water content (71.58 to 74.25%). The results in the current study provide evidence that the sonication-killed cells of B. logum SPM1207 isolated from healthy adult Koreans have a greater potential to be used as a cholesterol-lowering agent. Furthermore, the current study suggest that this killed specific strain may play role in part in blocking the body weight increase and relieving or eliminating constipation.

The combination of mixed lactic acid bacteria and dietary fiber lowers serum cholesterol levels and fecal harmful enzyme activities in rats.

Probiotics such as lactic acid bacteria (LAB) and prebiotics such as fiber are generally considered beneficial for health. These affect the microflora composition and fermentation metabolites and consequently contribute to local and systemic effects in humans. The beneficial effects of probiotics can be improved when combined with prebiotics. Here we investigated the effects of a mixed LAB supplement combined with dietary fiber on the population of LAB in the gut, as well as on serum cholesterol levels, fecal water content and microbial harmful enzyme activities. For animal studies, 0.2 mL of mixed LAB (Bifidobacterium longum SPM1205, Lactobacillus acidophilus, and SAFELAC isolated from Pediococcus pentosaceus) supplement (107 ∼ 108 colony forming units per day) was orally administered to male Sprague-Dawley rats every day for 2 weeks along with a diet containing 5% or 10% cellulose. The mixed LAB supplement combined with dietary cellulose significantly (p < 0.05) reduced serum total cholesterol and LDL levels. This combination also significantly (p < 0.05) increased the population of LAB and the fecal water content and significantly (p < 0.05) reduced microbial harmful enzyme (β-glucosidase, β-glucuronidase and tryptophanase) activities. These effects of LAB were particularly improved by its combination with 5% cellulose compared to the control (a diet without cellulose), and the 5% cellulose combination was more effective than the 10% cellulose combination. In conclusion, the incorporation of a fibrous diet such as cellulose with lactic acid bacteria improved the population of LAB, and daily consumption of this combination could reduce the serum cholesterol levels and activities of harmful enzymes such as β-glucosidase, β-glucuronidase, tryptophanase, urease in rats.

Antimicrobial activity of Bifidobacterium spp. isolated from healthy adult Koreans against cariogenic microflora

OBJECTIVEnDental caries is the main common infectious disease in the human oral cavity. Streptococcus mutans and Streptococcus sobrinus were reported to be the most important etiological factors in human dental caries. Thus, we examined the inhibitory effects of Bifidobacterium spp. cells and culture supernatants against S. mutans and S. sobrinus, including Streptococcus gordonii, and Aggregatibacter actinomycetemcomitans, which is associated with periodontal disease.nnnMETHODSnMutans streptococci or A. actinomycetemcomitans and lactic acid bacteria (LAB) were mixed in 1:1 ratio and then incubated for 90 min at 37°C. After the incubation, the viability of mutans streptococci or A. actinomycetemcomitans was determined by plate count technique. We also investigated the morphological changes of S. mutans treated with LAB using scanning electron microscopy (SEM).nnnRESULTSnIn vitro viability of S. mutans, S. sobrinus, S. gordonii, and A. actinomycetemcomitans was affected by human intestinal LAB identified as Bifidobacterium adolescentis SPM1005 and Bifidobacterium longum SPM1207. Especially, B. adolescentis SPM1005 cells at 1.0 × 10(8) CFU had a strong growth-inhibiting effect against S. mutans and induced a 64% loss of its viability (p<0.05). In addition, swollen and disrupted S. mutans were observed after incubation with B. adolescentis SPM1005. However, the culture supernatant of this strain did not show such inhibitory activity.nnnCONCLUSIONnB. adolescentis SPM1005 cells decreased the growth of S. mutans, which is a risk factor for dental caries. Therefore, we suggest that this Bifidobacterium strain may be a useful probiotic microorganism for prevention of dental caries that does not have adverse effects.

New antimicrobial drug resistance and epidemiological typing patterns of Staphylococci from clinical isolates and raw meats

The antimicrobial susceptibilities of Staphylococcus isolated from clinical isolates and raw meats were tested for six different antimicrobial agents that are in widespread clinical use in Korea and four new antimicrobials, linezolid, quinupristin/dalfopristin, daptomycin, and tigecycline. And this study analyzed the mecA genes and genetic patterns of MRSA by performing epidemiological studies using the PCR method. 46%, 51%, and 79% of clinical isolates were identified as MRSA in 1998, 1999, and 2005, respectively, and the mecA gene was detected in 82% of these isolates. Of the 133 staphylococci isolated from raw meats, 18% of the isolates were found to be resistant to methicillin, but none of these isolates showed the presence of the mecA gene. New antimicrobials, which have rarely or not yet been used in Korean hospitals, showed high activity against all staphylococcal isolates including methicillinresistant isolates. The randomaly amplified polymorphic DNA (RAPD) patterns of MRSA isolates differed significantly between clinical isolates and raw meat isolates.

Comparison of Dual Coated (Duolac™) and Uncoated Lactic Acid Bacteria from Potential Probiotics

ABSTRACT Probiotics do not naturally have a high stability and shelf life because they are living microorganisms. In an effort to maximise their survival, we have developed new dual coating LAB, trademarked as Duolac. This study aims to compare the probiotic effects of dual coated LAB and uncoated LAB, through in vivo and in vitro testing. Groups of SD rats were orally administered saline (as a control group), Duolac or uncoated LAB meal of 1x109 CFU per day for four weeks. We collected fecal samples to investigate the inhibition of harmful enzyme activity. At the end of the observation period, samples of organs were collected to determine hematological parameters and histological analysis in vivo. In order to assay the impact of Duolac on immunological function, we assessed tumor necrosis factor-α (TNF-α) activity and nitric oxide (NO) production in the murine macrophage RAW 264.7 cell line in vitro. In the safety study, blood biochemistry measurements and organ weight were similar and there was no observed difference in morbidity between the Duolac and uncoated LAB groups. The activities of hazardous enzymes were dramatically decreased in the Duolac group compared to the uncoated LAB group. Duolac efficiently produced TNF-α and NO in the murine macrophage RAW 264.7 cell line with LPS as standard. Thus, the results suggest that dual coated LAB can be used as functional probiotic for improving microbial balance in the intestinal tract and systemic immunity in humans.

Antiviral activity of Bifidobacterium adolescentis SPM 0214 against herpes simplex virus type 1

Herpes Simplex Virus type 1 (HSV-1) antibodies are found in up to 90 percent of the general population. About 30% of patients who have been exposed to HSV-1 develop recurrent infections, and this degree is continually increasing. In addition, resistance to all major anti-herpetic drugs such as acyclovir (ACV) has been increasingly reported. These observations underscore the importance of discovering new therapeutic tools for the treatment of HSV-1 infections. Bifidobacterium spp. has been studied in various fields including antibacterial and anticancer effect, but the antiviral activity was studied very little. The aim of this study was to test the antiviral activity of Bifidobacterium spp. against HSV-1. The Bifidobacterium adolescentis SPM 0214 used in this study through the screening of 23 Bifidobacterium spp. by plaque assay was assessed the cell viability assay in Vero cells. We also measured the plaque reduction assay and yield reduction assay after B. adolescentis SPM 0214 treatment at concentrations ranging between 10 and 104 μg/mL. The B. adolescentis SPM 0214 was not toxic to Vero cells, and the inhibition of plaque and yield formation was obviously increased compared to those of the control (no additive). Therefore, these results indicate that antiviral activity of B. adolescentis SPM 0214 against HSV-1.

Antimicrobial Activity of Commonly Used Antibiotics and DNA Fingerprint Analysis of Pseudomonas aeruginosa Obtained from Clinical Isolates and Unchlorinated Drinking Water in Korea, 2010

Pseudomonas aeruginosa exists in various environments, and can cause mild or serious infections resulting in a wide range of symptoms. In this study, we collected bacterial isolates from hospitalized patients and unchlorinated drinking water, in Korea, 2010. The water-borne and clinical isolates were compared using colony morphology, antimicrobial susceptibility testing, and random amplification of polymorphic DNA analysis. We first compared morphological features of the water-borne and clinical isolates. The clearest difference in colony morphology was colony shape; five water-borne isolate colonies (83%) had a smooth, circular morphology, while nine (75%) clinical isolate colonies had a rough, irregular morphology. Minimum inhibitory concentrations analyses were performed to determine antimicrobial resistant patterns; using ceftazidime, gentamicin, tigecycline, chloramphenicol, meropenem, and tobramycin according to Clinical and Laboratory Standard Institute (CLSI, 2009) methodology. All waterborne isolates were not resistant to gentamicin, tobramycin, and meropenem. The clinical isolates were resistant to every antibiotic except chloramphenicol. Genotyping was performed using the repetitive extragenic palindromic polymerase-chain-reaction. The DNA fingerprinting patterns did not reveal genetic similarity between the water-borne and clinical P. aeruginosa isolates. On the contrary, they showed that genetically distinct populations have been established in each of these environments. We have revealed significant morphological, clinical and genetic differences between water-borne and clinical isolates of the same bacterial species.

Producing Functional Soy-Based Yogurt Incubated with Bifidobacterium Longum SPM1205 Isolated from Healthy Adult Koreans

ABSTRACT In the present study Lactobacillus plantarum CBT1209, Pediococcus pentosaceus CBT SL4, and Bifidobacterium longum SPM1205 showed curd formation in soy milk for 8 hours of incubation time in a single-culture experiment. Among these strains, B. longum SPM1205 as a new isolated strain, inhibited the activity of fecal harmful enzymes of rat. Therefore, we investigated the possibility of using a mixed culture containing B. longum SPM1205for obtaining a curd-type soy-based yogurt with respect to curd formation, proximate composition and sensory attributes. Then we examined the changes in pH, lactic acid, and lactic acid bacteria during cold storage. B. longum SPM1205 was capable of producing moderate sour taste and good overall acceptability in curd-type plain soy-based yogurt for 8 hours of fermentation. Most sensory qualities were not significantly different in the strawberry soy-based yogurt compared to those of commercial milk-based yogurt. The pH of the strawberry soy-based yogurt decreased significantly (P < 0.05) during the days of storage (day 0, 5.18; day 1, 4.80), but the decrease slowed down after 3 days of storage. The lactic acid content and lactic acid bacteria population of plain and strawberry soy-based yogurt were not significantly changed over 10 days of storage. The products contained over 8 log of viable lactic acid bacteria. The results provide feasibility that a curd-type soy-based yogurt can be manufactured using B. longum SPM1205. However, more experiments are needed to improve the sensory qualities such as beany or astringent flavor and color.