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.

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 Student's 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.

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 (10(7) ∼ 10(8) 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.

Plant chitinases have been known as pathogenesis-related (PR) proteins, but recent studies suggest that they play functional roles during normal plant growth and development. We previously isolated two cDNA clones encoding endochitinases, EuNOD-CHT1 and .CHT2, from the root nodules of Elaeagnus umbellata. These genes show differential expression patterns, with the EuNOD-CHT1 gene being active in the root nodules and meristems, while EuNOD-CHT2 is preferentially expressed in the infected cells of those nodules. To elucidate the functional roles of these two endochitinases, we have now constitutively expressed each gene in a heterologous plant system, Arabidopsis thaliana. Stable inheritance and expression of the transgenes were confirmed by genomic Southern hybridization and RT-PCR. Our transgenic plants did not differ morphologically from the wild types. However, constitutive expression of EuNOD-CHT1 and -CHT2 in Arabidopsis resulted in increased resistance against a fungal pathogen, Botrytis cinerea, but not against a bacterial agent, Pseudomonas syringae pv. Tomato DC3000. Expression levels were enhanced by both wounding and jasmonic acid treatments (for EuNOD-CHT1), or by jasmonic acid only (for EuNOD-CHT2). These data suggest that EuNOD-CHT1 and -CfiT2 primarily play defensive roles during root nodule development in E. umbellata.

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 methicillin-resistant isolates. The randomly amplified polymorphic DNA (RAPD) patterns of MRSA isolates differed significantly between clinical isolates and raw meat isolates.