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A novel probiotics-derived protein, P8, suppresses the growth of colorectal cancer (CRC). P8 can penetrate the cell membrane via endocytosis and cause cell cycle arrest in DLD-1 cells through down-regulation of CDK1/Cyclin B1. However, neither the protein involved in the endocytosis of P8 nor the cell cycle arrest targets of P8 are known. We identified two P8-interacting target proteins [importin subunit alpha-4 (KPNA3) and glycogen synthase kinase-3 beta (GSK3β)] using P8 as a bait in pull-down assays of DLD-1 cell lysates. Endocytosed P8 in the cytosol was found to bind specifically to GSK3β, preventing its inactivation by protein kinases AKT/CK1ε/PKA. The subsequent activation of GSK3β led to strong phosphorylation (S 33,37 /T 41 ) of β-catenin, resulting in its subsequent degradation. P8 in the cytosol was also found to be translocated into the nucleus by KPNA3 and importin. In the nucleus, after its release, P8 binds directly to the intron regions of the GSK3β gene, leading to dysregulation of GSK3β transcription. GSK3β is a key protein kinase in Wnt signaling, which controls cell proliferation during CRC development. P8 can result in a cell cycle arrest morphology in CRC cells, even when they are in the Wnt ON signaling state.

In this study, the protective functions of bacteria-free conditioned media from Bifidobacterium and Lactobacillus species against ultraviolet radiation-induced skin ageing and associated cellular damage were investigated. The effects of ultraviolet radiation-induced reactive oxygen species production were suppressed by all conditioned media; particularly, the loss of cell viability and downregulation of collagen gene expression were significantly reversed by the conditioned media from B. longum and B. lactis . Further exa mination of potential anti-pigmentation effects revealed that the B. lactis -derived conditioned media significantly inhibited tyrosinase activity and alpha-melanocyte-stimulating hormone-induced melanin production in human epidermal melanocytes. Further, the conditioned media suppressed the phosphorylation of extracellular signal- related kinase, which functions as an upstream regulator of melanogenesis. Therefore, B. lactis -derived conditioned media can potentially protect against cellular damage involved in skin-ageing processes., (© 2022 Yoo Kyung Hong et al., published by Sciendo.)

Purpose: This study aimed to toxicological evaluate a probiotics-based delivery system for p8 protein as an anti-colorectal cancer drug., Introduction: Lactic acid bacteria (LAB) have been widely ingested for many years and are regarded as very safe. Recently, a Pediococcus pentosaceus SL4 (PP) strain that secretes the probiotic-derived anti-cancer protein P8 (PP-P8) has been developed as an anti-colorectal cancer (CRC) biologic by Cell Biotech. We initially identified a Lactobacillus rhamnosus (LR)-derived anti-cancer protein, P8, that suppresses CRC growth. We also showed that P8 penetrates specifically into CRC cells (DLD-1 cells) through endocytosis. We then confirmed the efficacy of PP-P8, showing that oral administration of this agent significantly decreased tumor mass (~42%) relative to controls in a mouse CRC xenograft model. In terms of molecular mechanism, PP-P8 induces cell-cycle arrest in G 2 phase through down-regulation of Cyclin B1 and Cdk1. In this study, we performed in vivo toxicology profiling to obtain evidence that PP-P8 is safe, with the goal of receiving approval for an investigational new drug application (IND)., Methods: Based on gene therapy guidelines of the Ministry of Food and Drug Safety (MFDS) of Korea, the potential undesirable effects of PP-P8 had to be investigated in intact small rodent or marmoset models prior to first-in-human (FIH) administration. The estimated doses of PP-P8 for FIH are 1.0×10 10 - 1.0×10 11 CFU/person (60 kg). Therefore, to perform toxicological investigations in non-clinical animal models, we orally administered PP-P8 at doses of 3.375 × 10 11 , 6.75 × 10 11 , and 13.5×10 11 CFU/kg/day; thus the maximum dose was 800-8000-fold higher than the estimated dose for FIH., Results: In our animal models, we observed no adverse effects of PP-P8 on clinicopathologic findings, relative organ weight, or tissue pathology. In addition, we observed no inflammation or ulceration during pathological necropsy., Conclusion: These non-clinical toxicology studies could be used to furnish valuable data for the safety certification of PP-P8., Competing Interests: All authors have no conflicts of interest to report., (© 2021 An et al.)

Excessive alcohol consumption is one of the most significant causes of morbidity and mortality worldwide. Alcohol is oxidized to toxic and carcinogenic acetaldehyde by alcohol dehydrogenase (ADH) and further oxidized to a non-toxic acetate by aldehyde dehydrogenase (ALDH). There are two major ALDH isoforms, cytosolic and mitochondrial, encoded by ALDH1 and ALDH2 genes, respectively. The ALDH2 polymorphism is associated with flushing response to alcohol use. Emerging evidence shows that Lactobacillus and Bifidobacterium species encode alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) mediate alcohol and acetaldehyde metabolism, respectively. A randomized, double-blind, placebo-controlled crossover clinical trial was designed to study the effects of Lactobacillus and Bifidobacterium probiotic mixture in humans and assessed their effects on alcohol and acetaldehyde metabolism. Here, twenty-seven wild types ( ALDH2*1/*1 ) and the same number of heterozygotes ( ALDH2*2/*1 ) were recruited for the study. The enrolled participants were randomly divided into either the probiotic (Duolac ProAP4) or the placebo group. Each group received a probiotic or placebo capsule for 15 days with subsequent crossover. Primary outcomes were measurement of alcohol and acetaldehyde in the blood after the alcohol intake. Blood levels of alcohol and acetaldehyde were significantly downregulated by probiotic supplementation in subjects with ALDH2*2/*1 genotype, but not in those with ALDH2*1/*1 genotype. However, there were no marked improvements in hangover score parameters between test and placebo groups. No clinically significant changes were observed in safety parameters. These results suggest that Duolac ProAP4 has a potential to downregulate the alcohol and acetaldehyde concentrations, and their effects depend on the presence or absence of polymorphism on the ALDH2 gene.

Background: Successful chemoprevention or chemotherapy is achieved through targeted delivery of prophylactic agents during initial phases of carcinogenesis or therapeutic agents to malignant tumors. Bacteria can be used as anticancer agents, but efforts to utilize attenuated pathogenic bacteria suffer from the risk of toxicity or infection. Lactic acid bacteria are safe to eat and often confer health benefits, making them ideal candidates for live vehicles engineered to deliver anticancer drugs., Results: In this study, we developed an effective bacterial drug delivery system for colorectal cancer (CRC) therapy using the lactic acid bacterium Pediococcus pentosaceus. It is equipped with dual gene cassettes driven by a strong inducible promoter that encode the therapeutic protein P8 fused to a secretion signal peptide and a complementation system. In an inducible CRC cell-derived xenograft mouse model, our synthetic probiotic significantly reduced tumor volume and inhibited tumor growth relative to the control. Mice with colitis-associated CRC induced by azoxymethane and dextran sodium sulfate exhibited polyp regression and recovered taxonomic diversity when the engineered bacterium was orally administered. Further, the synthetic probiotic modulated gut microbiota and alleviated the chemically induced dysbiosis. Correlation analysis demonstrated that specific bacterial taxa potentially associated with eubiosis or dysbiosis, such as Akkermansia or Turicibacter, have positive or negative relationships with other microbial members., Conclusions: Taken together, our work illustrates that an effective and stable synthetic probiotic composed of P. pentosaceus and the P8 therapeutic protein can reduce CRC and contribute to rebiosis, and the validity and feasibility of cell-based designer biopharmaceuticals for both treating CRC and ameliorating impaired microbiota. Video abstract.

Probiotics are known to protect against liver damage induced by the alcohol and acetaldehyde accumulation associated with alcohol intake. However, there have been few studies of the direct effect of probiotics on alcohol metabolism, and the types of probiotics that were previously analyzed were few in number. Here, we investigated the effects of 19 probiotic species on alcohol and acetaldehyde metabolism. Four probiotic species that had a relatively high tolerance to alcohol and metabolized alcohol and acetaldehyde effectively were identified: Lactobacillus gasseri CBT LGA1, Lactobacillus casei CBT LC5, Bifidobacterium lactis CBT BL3, and Bifidobacterium breve CBT BR3. These species also demonstrated high mRNA expression of alcohol and acetaldehyde dehydrogenases. ProAP4, a mixture of these four probiotics species and excipient, was then administered to rats for 2 weeks in advance of acute alcohol administration. The serum alcohol and acetaldehyde concentrations were significantly lower in the ProAP4-administered group than in the control and excipient groups. Thus, the administration of ProAP4, containing four probiotic species, quickly lowers blood alcohol and acetaldehyde concentrations in an alcohol and acetaldehyde dehydrogenasedependent manner. Furthermore, the serum alanine aminotransferase activity, which is indicative of liver damage, was significantly lower in the ProAP4 group than in the control group. The present findings suggest that ProAP4 may be an effective means of limiting alcohol-induced liver damage.

Background: The gut microbiota is closely associated with the bidirectional gut-brain axis that modulates neuropsychological functions of the central nervous system, thereby affecting mental disorders such as depression. Although it is known that probiotics affect brain functions, the impact of probiotics on the regulation of the prevalence and composition of gut microbiota, leading to anti-depressive effects has not been well understood., Methods: Mice were randomly divided into four different groups (n = 10 for each group) as follows: Group G1 (normal group) as control and group G2 (stress group) were given sterile saline via oral route daily for 8 weeks without and with stress condition, respectively. Under the stress condition, group G3 (fluoxetine group) was administered with fluoxetine hydrochloride and group G4 (probiotic group) was orally given multi-strains of probiotics daily for 8 weeks. After treatment, all mice underwent behavioral testing. Furthermore, fecal samples were collected from randomly selected 5 mice of each group on day 60 and taxonomical analysis of intestinal microbial distribution was performed., Results: Mice subjected to restraint stress showed depressive-like behaviors along with high corticosterone levels in serum. However, probiotic administration alleviated depressive-like behaviors and decreased corticosterone level. Moreover, fecal microbiota was distinctly altered in probiotic-treated mice of the stress group. The relative abundance of phylum and genus levels was significantly decreased in the stress group, but probiotic administration restored the composition of microbes restored., Conclusion: Ingested probiotics alter the composition of gut microbiota, likely improving the symptoms of depression. Graphical abstract Probiotic administration alters gut microbiota and reduces depressive-like behaviors.

Recently, we reported a novel therapeutic probiotic-derived protein, p8, which has anti-colorectal cancer (anti-CRC) properties. In vitro experiments using a CRC cell line (DLD-1), anti-proliferation activity (about 20%) did not improve after increasing the dose of recombinant-p8 (r-p8) to >10 μM. Here, we show that this was due to the low penetrative efficiency of r-p8 exogenous treatment. Furthermore, we found that r-p8 entered the cytosol through endocytosis, which might be a reason for the low penetration efficiency. Therefore, to improve the therapeutic efficacy of p8, we tried to improve delivery to CRC cells. This resulted in endogenous expression of p8 and increased the anti-proliferative effects by up to 2-fold compared with the exogenous treatment (40 μM). Anti-migration activity also increased markedly. Furthermore, we found that the anti-proliferation activity of p8 was mediated by inhibition of the p53-p21-Cyclin B1/Cdk1 signal pathway, resulting in growth arrest at the G 2 phase of the cell cycle. Taken together, these results suggest that p8 is toxic to cancer cells, shows stable expression within cells, and shows strong cancer suppressive activity by inducing cell cycle arrest. Therefore, p8 is a strong candidate for gene therapy if it can be loaded onto cancer-specific viruses.

The intestinal microbiota is closely associated with the development of obesity and nonalcoholic fatty liver disease (NAFLD). This study investigated the effects of probiotic treatment on visceral fat area (VFA) and intrahepatic fat (IHF) fraction in NAFLD. Sixty-eight obese NAFLD patients (>5% proton density fat fraction [PDFF] on magnetic resonance imaging [MRI]) were randomized to probiotic and placebo groups for 12 weeks. The probiotic mixture included 6 bacterial species. VFA and IHF were measured using the MRI-PDFF technique. Body weight and total body fat were reduced in the probiotic group but not in the placebo group. The mean IHF fraction was reduced after 12 weeks of treatment in the probiotic group compared to that at baseline (from 16.3 ± 15.0% to 14.1 ± 7.7%, p = 0.032) but was not reduced in the placebo group. The decrease in IHF (mean difference: -2.61%, p = 0.012) was also greater in the probiotic group than in the placebo group. Reduction of triglyceride was greater in the probiotic treatment group than in the placebo group (mean difference: -34.0 mg/dl, p = 0.0033). However, the changes in IHF percentage and triglyceride levels were not different between placebo and control groups after adjusting for changes in body weight. Treatment with probiotics for 12 weeks resulted in significant reduction in IHF and body weight in obese NAFLD patients.

Purpose: Obesity is a major public health concern. Despite its multi-factorial etiology, alterations in intestinal microbiota and the immune system are frequently observed. We investigated the effect of Duolac Gold (DG), a probiotic formulation containing 2 Lactobacillus strains (L. acidophilus LA1 and L. rharmnosus LR5), 3 Bifidobacterium (B. bifidum BF3, B. lactis BL3, and B. longum BG7), and Streptococcus thermophilus ST3, on morphometric and metabolic parameters, intestinal microbiota, and intestinal immune responses in a high-fat diet (HFD)-induced obese rat model., Methods: Rats received either a conventional balanced diet or HFD with or without water containing DG for 8 weeks. HFD-induced adiposity, intestinal microbiota, and changes in inflammatory cytokine, chemokine, and metabolite levels in serum were evaluated., Results: DG administration effectively decreased HFD-induced body weight and modulated morphometric and metabolic parameters. Quantitative analysis of fecal microbiota showed that obese rats given DG exhibited significantly increased levels of Bacteroidetes, Lactobacillus, and Bifidobacterium, with significant decreases in the level of Firmicutes. Serum levels of the inflammatory cytokines and the chemokine were also altered. Serum metabolite analysis revealed that DG administration modulated HFD-induced changes in serum metabolites, including fatty acids (FA), lysophosphatidylcholine, lysophosphatidylethanolamine, phosphatidylcholine (PC), and triacylglycerol (TAG)., Conclusions: DG administration appears to have the potential to alleviate HDF-induced obesity through the modulation of intestinal microbiota, immune responses, and host metabolism, which supports the use of probiotics to treat obesity.

Patients with metabolic disorders frequently suffer from side effects induced by long-term oral medications. The present study using a rat model system indicated that leflunomide (LF) and amlodipine (AMD), the active ingredients contained in the medications for rheumatoid arthritis and hypertension, respectively, appeared to induce various bowel problems including constipation and inflammation. In the small and large intestine, LF increased the expression of tumour necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 compared to the null control and AMD increased the expression of both TNF-α and IL-1β, although its effect on IL-6 was only increased in the large intestine. It is noteworthy that the probiotic blend tested was found to alleviate intestinal complications caused by LF and AMD. Analysis of the gut microbiota revealed that AMD induced compositional changes in the gut microbiota. Namely, members of the phylum Bacteroidetes, which constituted only about 0.3% of the microbiota in the null control, made up more than 10% of the total composition in the AMD-administered rats. Interestingly, the probiotic blend was also found to normaliSe the gut microbiota.

Inflammatory bowel disease (IBD) is a severe immune cell-mediated syndrome characterised by extensive inflammatory and effector mucosal responses leading to tissue destruction in the colon and small intestine. The leading hypothesis is that dysbiosis of the gut flora causes an excessive immune response and inflammation in the gastrointestinal track. Lactic acid bacteria (LAB) can correct dysbiosis of the normal microbiota. In the current study, the therapeutic potential of seven LAB strains in combination to treat IBD was evaluated using experimental colitis model. This LAB cocktail, designated GI7, includes four strains of Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis, two strains of Bifidobacterium bifidum, Bifidobacterium breve, and one strain of Streptococcus thermophilus. We confirmed that GI7 suppressed pro-inflammatory cytokines in Raw264.7 macrophages. When dextran sulphate sodium-induced colitic mice were treated with GI7, their symptoms of colitis, as assessed by body weight, colon length, myeloperoxidase activity, intestinal bleeding, and histological damage, were reduced compared to untreated mice. In addition, GI7 treatment significantly inhibited the production of innate pro-inflammatory cytokines during colitic progression. Therefore, we suggest that GI7, a combination of seven LAB, has a potential role in the treatment of IBD.

Treatment and prevention methods for non-steroidal anti-inflammatory drug-induced enteropathy have not yet been established. We tested the preventive effects of s-pantoprazole sodium trihydrate (PAN), polaprezinc (PZ), and probiotics on an indomethacin (Indo)-induced small intestinal injury in a rat model. Rats were randomised into 6 groups to receive: normal saline (control), Indo (6 mg/kg), PZ plus Indo, PAN plus Indo, or probiotics plus Indo (at 10 8 and 10 9 cfu/head) for 2 weeks. We measured body weight, food intake, severity of small intestinal damage, haemoglobin (Hb) levels in the small intestinal fluid, intestinal inflammatory cytokines, and a few groups of faecal bacteria. The experimental groups were found to have the following survival rates: 0% for the Indo, PZ, and PAN groups; 50% for both probiotic groups; and 100% for control. Treatment with probiotics of different concentrations reduced small intestinal lesion scores and intestinal fluid Hb as compared with the Indo group, while these parameters did not reduce in the PZ and PAN groups. The anti-inflammatory marker interleukin 10 increased in both probiotic groups. Analysis of a few groups of faecal bacteria revealed that Indo-induced a significant increase in Gram-negative bacteria and decreases in Bifidobacterium and Lactobacillus. Similar changes were also observed in the PZ and PAN groups. However, opposite effects were found in both probiotic groups. The use of probiotics appeared to be beneficial in preventing Indo-induced chronic small intestinal injury.

Bifidobacteria, often associated with the gastrointestinal tract of animals, are well known for their roles as probiotics. Among the dozens of Bifidobacterium species, Bifidobacterium bifidum, B. breve, and B. longum are the ones most frequently isolated from the feces of infants and known to help the digestion of human milk oligosaccharides. To investigate the correlation between the metabolic properties of bifidobacteria and their phylogeny, we performed a phylogenomic analysis based on 452 core genes of forty-four completely sequenced Bifidobacterium species. Results show that a major evolutionary event leading to the clade of the infant-adapted species is linked to carbohydrate metabolism, but it is not the only factor responsible for the adaptation of bifidobacteria to the gut. The genome of B. longum subsp. infantis, a typical bifidobacterium in the gut of breast-fed infants, encodes proteins associated with several kinds of species-specific metabolic pathways, including urea metabolism and biosynthesis of riboflavin and lantibiotics. Our results demonstrate that these metabolic features, which are associated with the probiotic function of bifidobacteria, are species-specific and highly correlate with their phylogeny., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Bifidobacteria constitute a major group of beneficial intestinal bacteria, and are therefore often used to formulate probiotic products in combination with lactic acid bacteria. The availability of bifidobacterial genome sequences has broadened our knowledge on health-promoting factors as well as their safety assessments. Here, we present the complete genome sequence of Bifidobacterium longum CBT BG7 that consists of a 2.45-Mb chromosome and a plasmid., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Helicobacter pylori is among the major pathogenic bacteria that cause chronic gastritis and peptic ulcer disease and is related to the development of gastric cancer. Several chemicals, including antibiotics, have been used to eradicate H. pylori; however, they do not always curb the infection. Ten representative type strains of lactic acid bacteria (LAB) were screened for antagonism toward H. pylori via inhibition of urease activity. Strains inhibiting the binding of H. pylori to human gastric cell line cells and suppressing H. pylori-induced interleukin-8 (IL-8) production were also screened. Of these, Pediococcus pentosaseus (SL4), which inhibited the adhesion of H. pylori to MKN-45 gastric cancer cells, Bifidobacterium longum (BG7), with urease inhibiting activity, and Lactococcus lactis (SL3), and Enterococcus faecalis (SL5), which suppressed H. pylori-induced IL-8 production within MKN-45 and AGS cells, were selected. In mouse model, these LAB stains in combination significantly suppressed IL-8 levels in serum. Gastric pH also recovered to normal values after the administration of these LAB. These stains effectively suppressed H. pylori viability, although not to the extent of antibiotic treatment. When used as probiotics, LAB may help decrease the occurrence of gastritis and reduce the risk of H. pylori infection without, inducing side effects.

Lactic acid bacteria (LAB) are probiotics that provide numerous beneficial effects on the host body, especially on the intestine. Combining several strains of LAB, we prepared a formulation containing four different LAB and studied its anti-inflammatory activity both in vitro and in vivo. The formulation significantly reduced NO production from RAW 264.7 cells treated with bacterial lipopolysaccharide, indicating that the formulation might include antiinflammatory activity. The formulation also suppressed inflammatory change induced by trinitrobenzene sulfonic acid (TNBS) in mice, where oral or rectal administration of the formulation protected the colon tissue from the damage by TNBS. Expressions of the IL-6 and FasL genes appeared to be down-regulated by the formulation in TNBS-treated colon tissues, suggesting that the suppression of those genes may be involved in the anti-inflammatory activity of the formulation.

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.

Objective: We doubly coated Lactobacillus plantarum KCTC3928 with proteins and polysaccharide compounds to enhance its acid and bile resistance. The present study investigated the hypocholesterolemic effects of double-coated L. plantarum KCTC3928 in C57BL/6 mice fed a high-fat diet. The effects of live and dead bacteria were compared., Methods: Six-week-old C57BL/6 male mice were divided into three groups: the control group was fed no L. plantarum KCTC3928, and the two treatment groups were orally fed live or dead L. plantarum KCTC3928 daily. Plasma and liver cholesterol and lipid levels, fecal bile acid, and gene and protein expressions were measured., Results: Low-density lipoprotein cholesterol and plasma triacylglycerol levels were significantly lower in the group fed live bacteria, by 42% and 32%, respectively (P<0.05), and fecal bile acid excretion was accelerated (+45%). Expression of the low-density lipoprotein receptor and 3-hydroxy-3-methylglutaryl coenzyme A reductase were marginally affected by the feeding of coated cells; however, the gene expression and protein levels of CYP7A1 were significantly upregulated after live L. plantarum KCTC3928 feeding (+80% for mRNA and +60% for protein expression)., Conclusion: Double-coated live L. plantarum KCTC3928 may have hypocholesterolemic effects in mice primarily due to induction of fecal bile acid secretion followed by increased degradation of hepatic cholesterol into bile acids. Studies in humans should confirm the effects in the future., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

The safety assessment of Bifidobacterium longum SPM1205 isolated from healthy Koreans and this strain's inhibitory effects on fecal harmful enzymes of intestinal microflora were investigated. The overall safety of this strain was investigated during a feeding trial. Groups of SD rats were orally administered a test strain or commercial reference strain B. longum 1 x 10(9) CFU/kg body weight/day for four weeks. Throughout this time, their feed intake, water intake and live body weight were monitored. Fecal samples were periodically collected to test harmful enzyme activities of intestinal microflora. At the end of the four-week observation period, samples of blood, liver, spleen, kidney, and gut tissues were collected to determine for hematological parameters and histological differences. The results obtained in this experiment demonstrated that four weeks of consumption of this Bifidobacterium strain had no adverse effects on rat's general health status, blood biochemical parameters or histology. Therefore, it is likely to be safe for human use. Fecal harmful enzymes such as beta-glucosidase, beta-glucuronidase, tryptophanase and urease, were effectively inhibited during the administration of the B. longum SPM1205. These results suggested that this B. longum SPM 1205 could be used for humans as a probiotic strain.

The intestinal microbiota are important to the host with regard to resistance they impart against bacterial infections and their involvement in mediating metabolic functions. Lactic acid producing bacteria such as Lactobacillus play an important physiological role in these matters. The aim of the present study was to isolate Lactobacillus sp. that inhibits enteric pathogens. Initially, 17 isolates from healthy Koreans were collected on Lactobacillus selective medium. Resistance of the isolates to antibiotics including rifampicin, streptomycin, clindamycin and vancomycin was measured. One of the isolate was identified as Lactobacillus ruminus on the basis of bacterial cell morphology, cultural characteristic and biochemical characteristics, 16S rRNA sequence analysis and PCR-RAPD. Antimicrobial activity of the bacterium against Vancomycin Intermediate Resistant Staphylococcus aureus (VISA) and Vancomycin-Resistant Enterococci (VRE) was measured. About 10(4) cells of VISA or VRE were mixed with 1, 5, and 9 mL of L. ruminus SPM 0211 and the final volume was adjusted to 10 mL with brain heart infusion (BHI) broth. The cell suspension was incubated for 3, 6, 9, and 24 h, serially diluted and then plated on BHI agar plates. As numbers of L. ruminus SPM 0211 were increased, viable cell count of VISA and VRE decreased. The strongest antimicrobial activity of SPM 0211 was observed after 9 h incubation in any mixture, almost completely inhibiting the growth of these two bacteria. The results suggest that the freshly isolated L. ruminus SPM 0211 may be used as a pro-biotic microbe that prevents the colonization of enteric pathogens and can thereby promote good gastrointestinal health.