Effects of Synbiotic2000™ Forte on the Intestinal Motility and Interstitial Cells of Cajal in TBI Mouse Model

The main objective of this study was to investigate the effects of Synbiotic2000? Forte on the intestinal motility and interstitial cells of Cajal (ICC) in traumatic brain injury (TBI) mouse model. Kunming mice were randomly divided into sham operation group (S group), enteral nutrition group with TBI (E group), and Synbiotic2000? Forte group with TBI (P group). The contractile activity of the intestinal smooth muscle, densities and ultrastructure of the ICC, kit protein concentration, weight, and defecation of mice were monitored and analyzed. TBI markedly suppressed contractile activity of the intestinal smooth muscle (P < 0.01), which led to a reduction of defecation (P < 0.01) and weight (P < 0.01). However, application of Synbiotic2000? Forte significantly improved contractile activity of the small intestine (P < 0.01), which may be related to protective effects to the interstitial cells of Cajal, smooth muscle cells, and enteric neurons. TBI impaired ICC networks and densities (P < 0.01), events that were protected by the application of Synbiotic2000? Forte. Synbiotic2000? Forte may attenuate TBI-mediated inhibition of the kit protein pathway. Synbiotic2000? Forte may improve intestinal motility and protect the ICC in the TBI mouse. These findings provide a novel support for the application of Synbiotic2000? Forte in intestinal motility disturbance after TBI.     

Screening of lactic acid bacteria with cholesterol-lowering and triglyceride-lowering activity in vitro and evaluation of probiotic function

To screen the lactic acid bacteria with cholesterol-lowering and triglyceride-lowering activity in vitro and evaluate their probiotic function. By plate separating, cholesterol-lowering and triglyceride-lowering activity in vitro were determined; and by evaluating the probiotic functions, including tolerances to simulated gastric and intestinal juice, the antibacterial spectrum, and the adhesion ability to Caco-2 cells, the probiotic strains with cholesterol-lowering and triglyceride-lowering activity in vitro were screened, and then were identified by phenotypical and physiological tests and 16Sr DNA. Finally, the cholesterol-lowering and triglyceride-lowering activity in vivo of the strains were evaluated using male Sprague-Dawley rats. Two strains L2-16 and L2-73 with stronger cholesterol-lowering and triglyceride-lowering activity in vitro, stronger tolerance to simulated gastric and intestinal juice and adhesion ability to Caco-2 cells, and wider antibacterial spectrum were screened from traditional Chinese fermented cucumber and were identified as Lactobacillus acidophilus and Enterococcus faecalis, respectively. Compared with a hyperlipidemia diet without lactic acid bacteria, the diet supplemented with Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 significantly reduced serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels, and liver total cholesterol and triglyceride levels in rats (P?<?0.05). Moreover, the diet supplemented with Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 significantly increased the fecal elimination of bile acids (P?<?0.05). Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 may have application prospect in the production of some fermented foods such as fermented vegetables, milk, or meat, and probiotic preparations with the function to lower the serum lipid and liver lipid levels.     

Detection and Specific Enumeration of Multi-Strain Probiotics in the Lumen Contents and Mucus Layers of the Rat Intestine After Oral Administration

Although the detection of viable probiotic bacteria following their ingestion and passage through the gastrointestinal tract (GIT) has been well documented, their mucosal attachment in vivo is more difficult to assess. In this study, we investigated the survival and mucosal attachment of multi-strain probiotics transiting the rat GIT. Rats were administered a commercial mixture of the intestinal probiotics Lactobacillus acidophilus LA742, Lactobacillus rhamnosus L2H and Bifidobacterium lactis HN019 and the oral probiotic Streptococcus salivarius K12 every 12 h for 3 days. Intestinal contents, mucus and faeces were tested 6 h, 3 days and 7 days after the last dose by strain-specific enumeration on selective media and by denaturing gradient gel electrophoresis. At 6 h, viable cells and DNA corresponding to all four probiotics were detected in the faeces and in both the lumen contents and mucus layers of the ileum and colon. Viable probiotic cells of B. lactis and L. rhamnosus were detected for 7 days and L. acidophilus for 3 days after the last dose. B. lactis and L. rhamnosus persisted in the ileal mucus and colon contents, whereas the retention of L. acidophilus appeared to be relatively higher in colonic mucus. No viable cells of S. salivarius K12 were detected in any of the samples at either day 3 or 7. The study demonstrates that probiotic strains of intestinal origin but not of oral origin exhibit temporary colonisation of the rat GIT and that these strains may have differing relative affinities for colonic and ileal mucosa.     

Alteration of the Canine Small-Intestinal Lactic Acid Bacterium Microbiota by Feeding of Potential Probiotics

Five potentially probiotic canine fecal lactic acid bacterium (LAB) strains, Lactobacillus fermentum LAB8, Lactobacillus salivarius LAB9, Weissella confusa LAB10, Lactobacillus rhamnosus LAB11, and Lactobacillus mucosae LAB12, were fed to five permanently fistulated beagles for 7 days. The survival of the strains and their potential effects on the indigenous intestinal LAB microbiota were monitored for 17 days. Denaturing gradient gel electrophoresis (DGGE) demonstrated that the five fed LAB strains survived in the upper gastrointestinal tract and modified the dominant preexisting indigenous jejunal LAB microbiota of the dogs. When the LAB supplementation was ceased, DGGE analysis of jejunal chyme showed that all the fed LAB strains were undetectable after 7 days. However, the diversity of the intestinal indigenous microbiota of the dogs, as characterized from jejunal chyme plated on Lactobacillus selective medium without acetic acid, was reduced and did not return to the original level during the study period. In all but one dog, an indigenous Lactobacillus acidophilus strain emerged as the dominant LAB strain. In conclusion, strains LAB8 to LAB12 have potential as probiotic strains for dogs as they survive in and dominate the jejunal LAB microbiota during feeding and have the ability to modify the intestinal microbiota.     

Expression of a Heterologous Manganese Superoxide Dismutase Gene in Intestinal Lactobacilli Provides Protection against Hydrogen Peroxide Toxicity

In living organisms, exposure to oxygen provokes oxidative stress. A widespread mechanism for protection against oxidative stress is provided by the antioxidant enzymes: superoxide dismutases (SODs) and hydroperoxidases. Generally, these enzymes are not present in Lactobacillus spp. In this study, we examined the potential advantages of providing a heterologous SOD to some of the intestinal lactobacilli. Thus, the gene encoding the manganese-containing SOD (sodA) was cloned from Streptococcus thermophilus AO54 and expressed in four intestinal lactobacilli. A 1.2-kb PCR product containing the sodA gene was cloned into the shuttle vector pTRK563, to yield pSodA, which was functionally expressed and complemented an Escherichia coli strain deficient in Mn and FeSODs. The plasmid, pSodA, was subsequently introduced and expressed in Lactobacillus gasseri NCK334, Lactobacillus johnsonii NCK89, Lactobacillus acidophilus NCK56, and Lactobacillus reuteri NCK932. Molecular and biochemical analyses confirmed the presence of the gene (sodA) and the expression of an active gene product (MnSOD) in these strains of lactobacilli. The specific activities of MnSOD were 6.7, 3.8, 5.8, and 60.7 U/mg of protein for L. gasseri, L. johnsonii, L. acidophilus, and L. reuteri, respectively. The expression of S. thermophilus MnSOD in L. gasseri and L. acidophilus provided protection against hydrogen peroxide stress. The data show that MnSOD protects cells against hydrogen peroxide by removing O₂^·− and preventing the redox cycling of iron. To our best knowledge, this is the first report of a sodA from S. thermophilus being expressed in other lactic acid bacteria.     

Antagonistic Activity of Lactobacillus acidophilus LB against Intracellular Salmonella enterica Serovar Typhimurium Infecting Human Enterocyte-Like Caco-2/TC-7 Cells

To gain further insight into the mechanism by which lactobacilli develop antimicrobial activity, we have examined how Lactobacillus acidophilus LB inhibits the promoted cellular injuries and intracellular lifestyle of Salmonella enterica serovar Typhimurium SL1344 infecting the cultured, fully differentiated human intestinal cell line Caco-2/TC-7. We showed that the spent culture supernatant of strain LB (LB-SCS) decreases the number of apical serovar Typhimurium-induced F-actin rearrangements in infected cells. LB-SCS treatment efficiently decreased transcellular passage of S. enterica serovar Typhimurium. Moreover, LB-SCS treatment inhibited intracellular growth of serovar Typhimurium, since treated intracellular bacteria displayed a small, rounded morphology resembling that of resting bacteria. We also showed that LB-SCS treatment inhibits adhesion-dependent serovar Typhimurium-induced interleukin-8 production.     

Effect of Lactobacillus acidophilus and Bifidobacterium bifidum supplementation to standard triple therapy on Helicobacter pylori eradication and dynamic changes in intestinal flora

To investigate Lactobacillus acidophilus (L. acidophilus) and Bifidobacterium bifidum (B. bifidum) supplementation to triple therapy for Helicobacter pylori (H. pylori) eradication and dynamic changes in intestinal flora in children with H. pylori infection. One hundred H. pylori-infected children were randomly assigned to two groups: treatment group (n = 43), standard triple anti-H. pylori therapy plus probiotics of L. acidophilus and B. bifidum for 2 weeks followed by taking probiotics for another 4 weeks; control group (n = 45), standard triple anti-H. pylori therapy for 6 weeks. After 6-week treatment, ¹³C-urease breath test was performed and side effects were monitored during the observation period. Quantitative PCR with 16S rRNA-gene-targeted species-specific primers was carried out for the analysis of human intestinal B. bifidum, L. acidophilus, and Escherichia coli (E. coli). As expected, treatment group could significantly enhance the H. pylori eradication rate (83.7 vs. 64.4 %, P < 0.05). B. bifidum, L. acidophilus, and E. coli showed no statistical difference before or after therapy in the treatment group. The number of B. bifidum and L. acidophilus was significantly decreased after 2-week treatment in the control group, but after 6-week treatment it significantly increased and nearly returned to the level before treatment. The number of E. coli increased significantly after 2-week treatment, while after 6-week treatment, it nearly decreased to the level before treatment. L. acidophilus and B. bifidum supplementation is effective for H. pylori eradication compared with triple therapy alone.     

Spermicidal and Contraceptive Potential of Desgalactotigonin: A Prospective Alternative of Nonoxynol-9

Crude decoction of Chenopodium album seed showed spermicidal effect at MIC 2 mg/ml in earlier studies. Systematic isolation, characterization and evaluation revealed that the major metabolite Desgalactotigonin (DGT) is the most effective principle in both in vitro and in vivo studies. The in vitro studies comprises (a) rat and human sperm motility and immobilizing activity by Sander-Cramer assay; (b) sperm membrane integrity was observed by HOS test and electron microscopy; (c) microbial potential was examined in Lactobacillus broth culture, and (d) the hemolytic index was determined by using rat RBCs. The in vivo contraceptive efficacy was evaluated by intra uterine application of DGT in rat. Lipid peroxidation and induction of apoptosis by DGT on human spermatozoa were also studied. The minimum effective concentration (MEC) of DGT that induced instantaneous immobilization in vitro was 24.18 µM for rat and 58.03 µM for human spermatozoa. Microbial study indicated DGT to be friendly to Lactobacillus acidophilus. Implantation was prevented in DGT treated uterine horn while no hindrance occurred in the untreated contra lateral side. At the level of EC₅₀, DGT induced apoptosis in human spermatozoa as determined by increased labeling with Annexin-V and decreased polarization of sperm mitochondria. Desgalactotigonin emerged 80 and 2×10⁴ times more potent than the decoction and Nonoxynol-9 respectively. It possesses mechanism based detrimental action on both human and rat spermatozoa and spares lactobacilli and HeLa cells at MEC which proves its potential as a superior ingredient for the formulation of a contraceptive safer/compatible to vaginal microflora.     

Effects of encapsulated Lactobacillus acidophilus along with pasteurized longan juice on the colon microbiota residing in a dynamic simulator of the human intestinal microbial ecosystem

The effect of encapsulated Lactobacillus acidophilus LA5 along with pasteurized longan juice on the colon microbiota was investigated by applying a dynamic model of the human gastrointestinal tract. Encapsulated L. acidophilus LA5 in pasteurized longan juice or sole encapsulated L. acidophilus LA5 exhibited the efficiency of colonizing the colon and enabling the growth of colon lactobacilli as well as beneficial bifidobacteria but inhibited the growth of fecal coliforms and clostridia. Moreover, these treatments gave rise to a significant increase of lactic acid and short-chain fatty acids such as acetate, propionate, and butyrate. Although acetate displayed the highest quantity, it was likely that after incorporating encapsulated L. acidophilus LA5 plus pasteurized longan juice, quantity of butyrate exceed propionate, and acetate in comparison with their controls. Denaturant gradient gel electrophoresis patterns confirmed that various treatments affected the alteration of microbial community within the simulator of the human intestinal microbial ecosystem.     

Differences in TLR9-dependent inhibitory effects of H2O2-induced IL-8 secretion and NF-kappa B/I kappa B-alpha system activation by genomic DNA from five Lactobacillus species

Lactic acid bacteria (LAB) show anti-inflammatory effects, and their genomic DNA was identified as one of the anti-inflammatory components. Despite the differences in anti-inflammatory effects between live LAB dependent not only on genus but also species, this effect has not been compared at the genomic DNA level. We compared the anti-inflammatory effects of the genomic DNA from five Lactobacillus species—Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus gasseri, Lactobacillus plantarum, and Lactobacillus reuteri—using Caco-2 cells. To evaluate anti-inflammatory effects, decreases in H₂O₂-induced IL-8 secretion and inhibition of H₂O₂-induced NF-κB/IκB-α system activation were examined. All LAB genomic DNAs dose-dependently decreased H₂O₂-induced IL-8 secretion and inhibited H₂O₂-induced NF-κB/IκB-α system activation. Comparison of these effects between Lactobacillus species showed that the anti-inflammatory effects of L. acidophilus genomic DNA are lower than those of the other species. Furthermore, suppression of Toll-like receptor 9 (TLR9), a specific receptor of bacterial DNA, expression by RNAi abolished the decrease of H₂O₂-induced IL-8 secretion and inhibition of H₂O₂-induced NF-κB/IκB-α system activation by LAB genomic DNA. Our results demonstrated that the anti-inflammatory effects of genomic DNA differ between Lactobacillus species and TLR9 is one of the major pathways responsible for the anti-inflammatory effect of LAB genomic DNA.     

Detection and Identification of Lactobacillus Species in Crops of Broilers of Different Ages by Using PCR-Denaturing Gradient Gel Electrophoresis and Amplified Ribosomal DNA Restriction Analysis

The microflora of the crop was investigated throughout the broiler production period (0 to 42 days) using PCR combined with denaturing gradient gel electrophoresis (PCR-DGGE) and selective bacteriological culture of lactobacilli followed by amplified ribosomal DNA restriction analysis (ARDRA). The birds were raised under conditions similar to those used in commercial broiler production. Lactobacilli predominated and attained populations of 10⁸ to 10⁹ CFU per gram of crop contents. Many of the lactobacilli present in the crop (61.9% of isolates) belonged to species of the Lactobacillus acidophilus group and could not be differentiated by PCR-DGGE. A rapid and simple ARDRA method was developed to distinguish between the members of the L. acidophilus group. HaeIII-ARDRA was used for preliminary identification of isolates in the L. acidophilus group and to identify Lactobacillus reuteri and Lactobacillus salivarius. MseI-ARDRA generated unique patterns for all species of the L. acidophilus group, identifying Lactobacillus crispatus, Lactobacillus johnsonii, and Lactobacillus gallinarum among crop isolates. The results of our study provide comprehensive knowledge of the Lactobacillus microflora in the crops of birds of different ages using nucleic acid-based methods of detection and identification based on current taxonomic criteria.     

ESR spin trapping for characterization of radical formation in Lactobacillus acidophilus NCFM and Listeria innocua

In this study, radicals in pure cultures of Lactobacillus acidophilus NCFM and Listeria innocua were detected in a quantitative way by electron spin resonance spectroscopy using spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) or N-tert-butyl-α-phenylnitrone (PBN). No adverse effect of spin trap addition on viability was observed for any of the bacterial strains. L. acidophilus NCFM had a higher production of radicals than L. innocua when incubated in a growth medium. Furthermore, by using DMPO in a buffer system, the radicals produced by L. acidophilus NCFM could be identified as hydroxyl radicals. The presence of polyethylene glycol, impermeable for bacterial cells, decreased the signal intensity of the ESR spectrum of the DMPO–OH adduct in cultures of L. acidophilus NCFM and indicated quenching of hydroxyl radicals outside the bacteria. This suggests that radical production is an extracellular event for L. acidophilus NCFM.     

A genome guided evaluation of the Lab4 probiotic consortium

Draft genome sequences of the Lab4 probiotic consortium were deposited in Genbank: Bifidobacterium animalis subsp lactis CUL34 (PRJNA482550), Bifidobacterium bifidum CUL20 (PRJNA559984), Lactobacillus acidophilus CUL60 (PRJNA482335), Lactobacillus acidophilus CUL21 (PRJNA482434). Probiogenomic analyses confirmed existing taxonomies and identified putative gene sequences that were functionally related to the performance of each organism during in vitro assessments of bile and acid tolerability, adherence to enterocytes and susceptibility to antibiotics. Genomic stability predictions identified no significant risk of gene acquisition of both antibiotic resistance and virulence genes. These observations were supported by acute phase and repeat dose tolerability studies in Wistar rats. High doses of Lab4 did not result in mortalities, clinical/histopathological abnormalities nor systemic toxicity. Increased faecal numbers of Lab4 in supplemented rats implied survival through the gastrointestinal tract and/or impact the intestinal microbiota composition. In summary, this study provides multifaceted support for probiotic functionality and the safety of the Lab4 consortium.     

Antagonistic activity of Lactobacillus acidophilus RY2 isolated from healthy infancy feces on the growth and adhesion characteristics of enteroaggregative Escherichia coli

Enteroaggregative Escherichia coli (EAggEC) infection is an important cause of acute diarrhea, affecting children in developing countries and travelers visiting tropical or subtropical areas. Three probiotics can exert bacteriostatic or bactericidal effects on human and animal intestinal pathogens, the efficiency of probiotics on EAggEC infection remains unclear. In this study, the antagonistic activity of probiotic bacteria isolated from infant faeces was examined against several EAggEC stains. While three isolates, Lactobacillus acidophilus RY2, Lactobacillus salivarius MM1 and Lactobacillus paracasei En4 were shown to significantly inhibit the growth of EAggEC. In addition, the antagonistic activity of the Lactobacillus species was maintained despite heating (100 °C, 15 min) of cell free culture supernatant (CFCS). The antagonistic activity of the CFCS however, could be reduced following lactate dehydrogenase treatment and at pH 7.2. Furthermore, in an adhesion–inhibition assay, L. acidophilus RY2 was shown to be more effective than L. salivarius MM1 and L. paracasei EN4. This study suggests that L. acidophilus RY2 could be used as a probiotic organism against EAggEC.     

Lactobacillus acidophilus K301 Inhibits Atherogenesis via Induction of 24 (S), 25-Epoxycholesterol-Mediated ABCA1 and ABCG1 Production and Cholesterol Efflux in Macrophages

Lactobacillus acidophilus species are well-known probiotics with the beneficial activity of regulating cholesterol levels. In this study, we showed that L. acidophilus K301 reduced the level of cholesterol through reverse transport in macrophages. L. acidophilus K301 upregulated the mRNA and protein levels of genes such as ATP-binding cassette A1 (ABCA1) and ATP-binding cassette G1 (ABCG1) under the control of liver X receptor (LXR), resulting in increased apoA-I-dependent cholesterol efflux in phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 cells. L. acidophilus K301 induced both ABCA1 and ABCG1 through the endogenous LXR agonist 24(S), 25-epoxcycholesterol, which is synthesized by intracellular cholesterol synthetic pathways. In vivo studies using L. acidophilus K301-treated ApoE^-/- mice showed reduced accumulation of lipoproteins in the arterial lumen. The inhibitory effects of L. acidophilus K301 on accumulation of lipoprotein in atherosclerotic plaques were mediated by the induction of squalene reductase (SQLE) and oxidosqualene cyclase (OSC) and resulted in ABCA1-mediated cholesterol efflux. Taken together, our findings revealed that Lactobacillus acidophilus K301 regulates the expression of genes related to cholesterol reverse transport via the induction of endogenous LXR agonist, suggesting the therapeutic potential of Lactobacillus acidophilus K301 as an anti-atherosclerotic agent.     

Supportive Role of Probiotic Strains in Protecting Rats from Ovariectomy-Induced Cortical Bone Loss

Osteoporosis is a major health problem that occurs as a result of an imbalance between bone formation and bone resorption. Different approaches have been established for treating osteoporosis. Recently, because of their health benefits and also low adverse reaction, probiotics have been receiving considerable attention. In this study, we compared the effectiveness of five probiotic strains, Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei, Bifidobacterium longum, and Bacillus coagulans, in protecting rats from ovariectomized (OVX)-induced bone loss. Forty-nine adult female Sprague-Dawley rats were allocated into seven groups as follows: group 1, control; group 2, OVX; group 3, OVX + Lactobacillus acidophilus; group 4, OVX + Lactobacillus casei; group 5, OVX + Bacillus coagulans; group 6, OVX + Bifidobacterium longum; and group 7, OVX + Lactobacillus reuteri. Probiotics were fed to OVX groups at the concentration of (1 × 10⁹ CFU/ml/day) for 4 weeks. Then, biochemical parameters, including vitamin D, calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP), were assessed. Dual-energy X-ray absorptiometry (DEXA) scans were used that assess bone mineral density (BMD), bone marrow concentration (BMC), and area of global, femur, spine, and tibia. Lactobacillus acidophilus and Lactobacillus casei significantly increased Ca and ALP and decreased P in treated groups. Lactobacillus casei, Lactobacillus reuteri, and Bifidobacterium longum increased vitamin D significantly. Lactobacillus acidophilus and Lactobacillus casei indicated the most effects on BMD. In terms of BMC, and bone area, Lactobacillus acidophilus, Lactobacillus reuteri, and Lactobacillus casei demonstrated the significant enhancement in OVX groups treated with. Among the probiotics used in this study, Lactobacillus acidophilus and Lactobacillus casei showed the most effects in terms of BMD, BMC, bone area, and biochemical parameters. It seems that probiotics effects on bone health are strain dependent, but further studies should be done to prove these findings.

     

Metabolism of biodiesel-derived glycerol in probiotic Lactobacillus strains

Three probiotic Lactobacillus strains, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus delbrueckii, were tested for their ability to assimilate and metabolize glycerol. Biodiesel-derived glycerol was used as the main carbon and energy source in batch microaerobic growth. Here, we show that the tested strains were able to assimilate glycerol, consuming between 38 and 48 % in approximately 24 h. L. acidophilus and L. delbrueckii showed a similar growth, higher than L. plantarum. The highest biomass reached was 2.11 g?L^?1 for L. acidophilus, with a cell mass yield (Y _X/S) of 0.37 g?g^?1. L. delbrueckii and L. plantarum reached a biomass of 2.06 and 1.36 g?L^?1. All strains catabolize glycerol mainly through glycerol kinase (EC 2.7.1.30). For these lactobacillus species, kinetic parameters for glycerol kinase showed Michaelis–Menten constant (K _m) ranging from 1.2 to 3.8 mM. The specific activities for glycerol kinase in these strains were in the range of 0.18 to 0.58 U?mg?protein^?1, with L. acidophilus ATCC 4356 showing the maximum specific activity after 24 h of cultivation. Glycerol dehydrogenase activity was also detected in all strains studied but only for the reduction of glyceraldehyde with NADPH (K _m for DL-glyceraldehyde ranging from 12.8 to 32.3 mM). This enzyme shows a very low oxidative activity with glycerol and NADP⁺ and, most likely, under physiological conditions, the oxidative reaction does not occur, supporting the assumption that the main metabolic flux concerning glycerol metabolism is through the glycerol kinase pathway.     

Antioxidant properties of potentially probiotic bacteria: in vitro and in vivo activities

Thirty-four strains of lactic acid bacteria (seven Bifidobacterium, 11 Lactobacillus, six Lactococcus, and 10 Streptococcus thermophilus) were assayed in vitro for antioxidant activity against ascorbic and linolenic acid oxidation (TAA_AA and TAA_LA), trolox-equivalent antioxidant capacity (TEAC), intracellular glutathione (TGSH), and superoxide dismutase (SOD). Wide dispersion of each of TAA_AA, TAA_LA, TEAC, TGSH, and SOD occurred within bacterial groups, indicating that antioxidative properties are strain specific. The strains Bifidobacterium animalis subsp. lactis DSMZ 23032, Lactobacillus acidophilus DSMZ 23033, and Lactobacillus brevis DSMZ 23034 exhibited among the highest TAA_AA, TAA_LA, TEAC, and TGSH values within the lactobacilli and bifidobacteria. These strains were used to prepare a potentially antioxidative probiotic formulation, which was administered to rats at the dose of 10⁷, 10⁸, and 10⁹ cfu/day for 18 days. The probiotic strains colonized the colon of the rats during the trial and promoted intestinal saccharolytic metabolism. The analysis of plasma antioxidant activity, reactive oxygen molecules level, and glutathione concentration, revealed that, when administered at doses of at least 10⁸ cfu/day, the antioxidant mixture effectively reduced doxorubicin-induced oxidative stress. Probiotic strains which are capable to limit excessive amounts of reactive radicals in vivo may contribute to prevent and control several diseases associated with oxidative stress.     

Casein-Derived Antimicrobial Peptides Generated by Lactobacillus acidophilus DPC6026

Three peptides produced by a Lactobacillus acidophilus DPC6026 fermentation of sodium caseinate and showing antibacterial activity against pathogenic strains Enterobacter sakazakii ATCC 12868 and Escherichia coli DPC5063 were characterized. These peptides were all generated from bovine α_s1-casein and identified as IKHQGLPQE, VLNENLLR, and SDIPNPIGSENSEK. These peptides may have bioprotective applicability and potential use in milk-based formula, which has been linked to E. sakazakii infection in neonates.     

Detection of Lactobacillus acidophilus in Feces of Humans, Pigs, and Chickens

Lactobacilli in fecal material from humans, pigs, and chickens were enumerated on lactobacillus selective agar (LBS). In all samples, higher numbers of lactobacilli were detected when plates were incubated in a system flushed with CO₂ rather than in air. Much higher numbers of bacteria from human feces were detected when the LBS agar plates were incubated anaerobically in a hydrogen-carbon dioxide atmosphere (GasPak) than when incubated in CO₂. The bacteria from human feces isolated on LBS agar incubated anaerobically were predominately bifidobacteria. Cultures from all three sources isolated on LBS agar incubated under CO₂ were lactobacilli, including Lactobacillus acidophilus. Differences were observed in biochemical characteristics of some of the L. acidophilus isolated from all three sources. Guanine plus cytosine base ratios of deoxyribonucleic acid isolated from L. acidophilus cultures from humans were lower, in most cases, than those from pigs and chickens.