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Aims There is interest in using probiotics such as Lactobacillus species to control canine intestinal infections. The bacterial species should be of canine intestinal origin exhibiting host specificity. Bacterial strains were isolated from dog faecal samples and characterized to select specific probiotics as dietary supplements in feed, promoting health status. Methods and results Bacterial strains have been screened for their probiotic properties including survival to gastric and pancreatic juices and bile salts, resistance to antibiotics and antipathogenicity. Five of 14 isolated Lactobacillus strains were tolerant to gastric stress. They were also resistant to clindamycin and with a significant antimicrobial capacity towards the pathogenic strains tested, variable according to the strain. They were identified by morphological and molecular characterization comparing the 16S rRNA gene sequence with the blast database. Three strains were identified as Lactobacillus reuteri and two as Lactobacillus johnsonii. Sugar fermentation profiles and adhesion to HT29 epithelial cells have been in vitro verified on L. reuteri AI, chosen as probiotic candidate. Resistance to freeze-drying, production and subsequent in vivo administration evaluating strain permanence, were also performed. No loss of vitality has been recorded due to the freeze-drying process. The average value of recovery percentage of L. reuteri AI at the end of the administration period and after 1 week of follow-up was respectively 26·7 and 17·4% of the total Lactobacillus sp. Conclusions Among several selected probiotic strains, L. reuteri AI proved to be the best probiotic candidate to use as a supplement for dogs. Significance and impact of the study Control of intestinal pathogenic micro-organisms in dogs is a growing concern and the selection of autochthonous probiotic bacterial strains to overcome some of the gut problems associated with the modern domestication of animals is a valuable tool.

Aims Probiotics have the ability to enhance the immune system, produce anti-inflammatory action and promote wound healing process. The first aim of the study was to isolate pathogenic micro-organisms from sites of chronic ulcerative lesion. The second aim was to evaluate probiotic efficacy of SYNBIO® (1:1 combination of Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® ) in counteracting wound infections. Methods and results Several bacterial pathogens were isolated from chronic ulcerative lesions and identified by morphological, biochemical and molecular techniques. SYNBIO® probiotic formulation was investigated for its antimicrobial activity, minimum inhibitory concentration, co-aggregation and adherence capacity against the isolated pathogens. Moreover, SYNBIO was also tested in combination with some medical devices, using an in vitro model, in order to simulate a real ulcerative wound infection. Probiotic formulation demonstrated an inhibitory action against all the tested pathogens and their mixture (MIX), with an increased ability of co-aggregation during time. In addition, the adhesion percentage of probiotic micro-organisms to human keratinocyte (HaCaT cells) and human fibroblasts (NHF), calculated by an in vitro model, was 19% and 17% respectively, highlighting the possibility to create a protective environment preventing pathogens' biofilm formation in order to contrast infections. Conclusions SYNBIO® probiotics showed a very good antimicrobial capacity and adhesion percentage to HaCaT cells and fibroblasts, giving the opportunity to be successfully used as complement to conventional therapies in the treatment of chronic ulcerative lesions. Significance and impact of the study A new therapeutic approach with probiotics (supplemented in topical applications, excluding side effects) able to eliminate pathogenic micro-organisms and improve healing of chronic ulcerative lesions.

The types and methods of use of antibiotics in poultry farms in Cameroon, residual levels and potential microbial resistance were determined.A questionnaire-based survey identified the different antibiotics used and high-performance liquid chromatography (HPLC) was used to determine residual levels of antibiotics.Pathogens were isolated, identified by use of commercial API kits and minimum inhibition concentration (MIC) was determined.Oxytetracyclin, tylocip and TCN (oxytetracycline, chloramphenicol and neomycin) were the most frequently used antibiotics. Antibiotics screened by HPLC were chloramphenicol, tetracycline and vancomycin. All of them except vancomycin were detected, and the concentration of these antibiotics was higher than the maximum residual limits (MRL) set by regulatory authorities.No residues of various antibiotics were found in egg albumen or yolk. The concentration of tetracycline was significantly higher in liver (150 ± 30 µg/g) than in other tissues.Foodborne pathogens, including Salmonella spp., Staphylococcus spp., Listeria spp., Clostridium spp. and Escherichia spp., were identified. Most of the pathogens were resistant to these various antibiotics tested.These findings imply the need for better management of antibiotic use to control sources of food contamination and reduce health risks associated with the presence of residues and the development of resistant pathogens by further legislation and enforcement of regulations on food hygiene and use of antibiotics. The types and methods of use of antibiotics in poultry farms in Cameroon, residual levels and potential microbial resistance were determined. A questionnaire-based survey identified the different antibiotics used and high-performance liquid chromatography (HPLC) was used to determine residual levels of antibiotics. Pathogens were isolated, identified by use of commercial API kits and minimum inhibition concentration (MIC) was determined. Oxytetracyclin, tylocip and TCN (oxytetracycline, chloramphenicol and neomycin) were the most frequently used antibiotics. Antibiotics screened by HPLC were chloramphenicol, tetracycline and vancomycin. All of them except vancomycin were detected, and the concentration of these antibiotics was higher than the maximum residual limits (MRL) set by regulatory authorities. No residues of various antibiotics were found in egg albumen or yolk. The concentration of tetracycline was significantly higher in liver (150 ± 30 µg/g) than in other tissues. Foodborne pathogens, including Salmonella spp., Staphylococcus spp., Listeria spp., Clostridium spp. and Escherichia spp., were identified. Most of the pathogens were resistant to these various antibiotics tested. These findings imply the need for better management of antibiotic use to control sources of food contamination and reduce health risks associated with the presence of residues and the development of resistant pathogens by further legislation and enforcement of regulations on food hygiene and use of antibiotics.

A diet rich in fruit provides nutrients that are vital for human health. In particular, the anthocyanins contained in fruit have received attention due to their health-promoting properties and antioxidant, anti-inflammatory and antimicrobial activities. In this study, total phenolic, anthocyanin, flavonoid content and antioxidant activity were determined in extracts from plum skins, Italian red grape skins, and different parts of elderberry. Furthermore, it was analysed the activity of the fruit extracts in inhibiting several pathogens and in stimulating the growth of three probiotic strains and one blend SYNBIO®. All extracts show a good content of anthocyanins, exhibited high antioxidant activity and significantly inhibited the pathogens tested. The extracts had no inhibitory activity on the probiotic strains, but rather, they stimulated the growth of all the probiotics. In order to test the potential prebiotic properties of these anthocyanin-rich red fruit extracts, the kinetic growth of all probiotics was monitored, and it was found that probiotics in presence of elderberry and plum extracts had a significant increase in mean doubling time. The combined formulation of elderberry extracts and each of the four probiotics showed higher antioxidant activity compared to that of the extract alone, indicating the ability of probiotics to increase the antioxidant activity of the elderberry extracts. The fruit extracts used in this study can be considered beneficial for human health, due to their high content of polyphenols, particularly anthocyanins. Based on their antioxidant and antimicrobial activities, these fruit extracts can be considered good candidates for designing new functional foods and beverages, as well as nutraceuticals. Moreover, the ability of the fruit extracts to stimulate the growth of the probiotics merits further study to ascertain whether they can be defined as prebiotics.

The purpose of this study was to investigate whether vaginal administration of probiotic Lactobacillus results in their colonization and persistence in the vagina and whether it promotes normalization and maintenance of pH and Nugent score. A single-arm, open-label controlled towards the baseline (pre–post) study including 35 apparently healthy women was conducted. Each woman was examined three times during the study. Women were instructed to receive daily for 7 days, the probiotic suppositories SYNBIO® gin (Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502®). Vaginal swabs were collected during visit 1, 2, and 3 to determine the total lactobacilli count, the presence of the two administered bacteria, the measure of the pH, and the estimation of Nugent score. Evaluation of treatment tolerability was based on analysis of the type and occurrence of adverse events. The probiotic vaginal suppository was well tolerated and no side effects were reported. Intermediate Nugent score was registered in 40 % of women at visit 1 and these intermediate scores reverted to normal at day 7 (end of treatment) in 20 % of subjects. Administration of SYNBIO® gin contributed to a significant increase in the lactobacilli level at visit 2. Molecular typing revealed the presence of the two strains originating from SYNBIO® gin in 100 % of women at visit 2 and 34 % at visit 3. No significant changes were registered for pH between visits. The SYNBIO® gin product is safe for daily use in healthy women and it could be useful to restore and maintain a normal vaginal microbiota.

The possibility of using microbes to maintain health, and to prevent or treat disease is a topic as old as microbiology. The research of novel probiotic strains is important in order to satisfy the increasing request of the market and to obtain functional products in which the probiotic cultures are more active and with better probiotic characteristics than those already present on the market. In this study, the probiotic potential of Lactobacillus strains isolated from Italian elderly human faeces was investigated. The Lactobacillus strains were identified and examined for resistance to gastric acidity and bile toxicity, adhesion to HT-29 cells, antimicrobial activities, antibiotic susceptibility and plasmid profile. Survival of the strains through human intestine was examined in a 3 months human feeding trial. Two strains, Lactobacillus rhamnosus IMC 501 and Lactobacillus paracasei IMC 502, tolerated well low pH and bile acids. In antimicrobial activity assays, both strains showed inhibitory properties towards selected potential harmful microorganisms, particularly against Candida albicans. The two selected strains expressed high in vitro adherence to HT-29 cells increasing this characteristic when they are used in combination and they were resistant to vamcomycin, colistin sulphate, gentamicin, oxolinic acid and kanamycin. Moreover, the two strains could be recovered from stools of volunteers after the feeding trials. Lactobacillus rhamnosus IMC 501 and L. paracasei IMC 502 present favourable strain-specific properties for their utilisation as probiotics in functional foods and the high adhesion ability of the L. rhamnosus IMC 501 and L. paracasei IMC 502 used in combination, confirmed by both in vitro and in vivo study, indicate that the two bacterial strains could be used as health-promoting bacteria.

Aims To characterize in vitro the ability of human Lactobacillus strains to inhibit the adhesion, to displace and to compete with clinically isolated Candida strains. Methods and Results Three types of assays were performed to determine the inhibitory effect of Lactobacillus plantarum 319, Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and a specific probiotic combination (SYNBIO®) on adhesion of Candida pathogens to HeLa cells: blockage by exclusion (lactobacilli and HeLa followed by pathogens), competition (lactobacilli, HeLa and pathogens together) and displacement (pathogens and HeLa followed by the addition of lactobacilli). Bacterial adhesion to HeLa was quantified by microscopy after May-Grunwald/Giemsa stain. The inhibition results highlight a significant (P

Two bacterial strains, Lactobacillus fructivorans, isolated from sea bream (Sparus aurata) gut, and Lactobacillus plantarum, isolated from human faeces, were administered simultaneously, during sea bream development, using Brachionus plicatilis and/or Artemia salina as vectors. The probiotic treatment significantly affected gut colonization. To test the probiotic influence on stress responsiveness, sea bream fry, 47 days post-hatching (p.h.), were subjected to pH stress (from 8.6 to 6.3) and cumulative mortality, cortisol levels and HSP70 gene expression were analysed. Cortisol was selected, since under stress conditions its level increases. HSP70 was selected with consideration of its wide involvement in response to a great number of injuries, and because it protects cells probably by binding and refolding damaged proteins. The results obtained indicated that the administration of probiotic to sea bream fry induced higher HSP70 levels, indicating a greater potentiality to respond to the harmful conditions possibly present in fish farms. This hypothesis is supported by the fact that the levels of cortisol found were significantly lower (P

Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult sea bream (Sparus aurata) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously, during sea bream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. The probiotic treatment influenced gut colonization: at 35 days post-hatching (p.h.) L. fructivorans was not present in the gut, but the treatment induced colonization by L. plantarum. At 66 days p.h., L. fructivorans was evident also in the control; moreover, when suitable environmental conditions appeared in the post-metamorphosis gastro-intestinal tract, competition between L. plantarum and L. fructivorans occurred. At 90 days p.h., L. plantarum was displaced by L. fructivorans that became significantly higher with respect to the control. In treated groups, probiotic administration significantly decreased larvae and fry mortality.

A new EU-funded project called “Crownalife” has been set up both to assess structural and functional alterations of the intestinal microflora with ageing in Europe, and to validate functional foods that promote health by improving the function of the intestinal microflora in the elderly. Species of bifidobacteria and lactobacilli were isolated from faecal samples of healthy elderly Italian subjects and identified for a possible probiotic use in functional foods. Total anaerobic and aerobic, Lactobacillus and Bifidobacterium counts were performed on the faecal samples. Colonies grown on selective media were identified using enzymatic tests. Lactobacillus fermentum and Bifidobacterium longum were the most represented species and could be considered good candidates to be further characterized and then utilized to design appropriate dietary strategies. Some of the identification results related to Bifidobacterium species were validated by using PCR procedure based on 16S rRNA gene sequences species-specific primers showing a good concordance rate with the enzymatic method.

Aims To assess the activity of biostatic agents on the microbial colonization of panel filters. Methods and results Microfibre glass acrylic filters, both used and unused, were examined for the presence of microorganisms. Test strains were used to verify microbial colonization of filter media. Antimicrobial agents were applied to the filter media and tested for their ability to reduce microbial colonization. The integrity of the panel filters and the antimicrobial activity trends of the filter media treated with antimicrobials were verified. A filtration efficiency test was carried out on the treated filters to evaluate filtration performance. Filters treated with antimicrobials demonstrated markedly less microbial colonization (density and varieties of species), higher filtration efficiency and delayed deterioration of the filter. Conclusions The most important results of this study are the demonstration of preservation of the integrity of the filters and the lower release of microorganisms from treated filters. Significance and impact of the study These results contribute to the resolution of problems concerning the microbial contamination of panel filters in the heating, ventilating and air-conditioning systems commonly used in the electronic industry, pharmaceutical industry, hospitals and other environments where the absence of contaminating particles and microorganisms is required.

We studied the correlation between fecal levels of short-chain fatty acids (SCFA), bile acids (BA), and colonic mucosal proliferation in humans on a free diet. Subjects [n = 43: 27 men and 16 women; 61 +/- 7 and 59 +/- 6 (SE) yr old, respectively] were outpatients who previously underwent resection of at least two sporadic colon polyps. Mucosal proliferation was determined by [3H]thymidine incorporation in vitro in three colorectal biopsies obtained without cathartics and was expressed as labeling index (LI). BA were analyzed in feces by mass spectrometry and SCFA by gas chromatography. We found that increasing levels of BA in feces did not correlate with higher LI. On the contrary, higher levels of SCFA were significantly associated with lower LI in the colonic mucosa (P for trend = 0.02). In conclusion, in humans on a free diet, intestinal proliferation seems to be regulated by the levels of SCFA in feces and not by BA. Because a lower intestinal proliferation is associated with a decreased colon cancer risk, treatments or diets that increase colonic levels of SCFA might be beneficial for colonic mucosa.

A randomised, double-blind, placebo-controlled, parallel group study assessed in healthy adults how daily consumption of the probiotic combination SYNBIO®, administered in probiotic-enriched foods or in a dietary supplement, affected bowel habits. Primary and secondary outcomes gave the overall assessment of bowel well-being, while a Psychological General Well-Being Index compiled by participants estimated the health-related quality of life as well as the gastrointestinal tolerance determined with the Gastrointestinal Symptom Rating Scale. Support Vector Machine models for classification problems were used to validate the total outcomes on bowel well-being. SYNBIO® consumption improved bowel habits of volunteers consuming the probiotic foods or capsules, while the same effects were not registered in the control groups. The recovery of probiotic bacteria from the faeces of a cohort of 100 subjects for each supplemented group showed the persistence of strains in the gastrointestinal tract.

Aims Probiotic lactobacilli have a great potential to produce antimicrobial compounds that inhibit and control the microbial pathogen growth. The antimicrobial and antifungal activities of two probiotic strains, Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502®, and their 1 : 1 combination, named SYNBIO®, were studied using four different methods. Methods and Results Using two modified streak methods and a well diffusion method, the inhibitory activity of the probiotics and their metabolites towards six Gram-positive, nine Gram-negative pathogenic bacterial strains and eight Candida strains was tested. Antagonistic effect of probiotic Lactobacillus strains was also investigated by coculturing assay highlighting a significant inhibition of most of the pathogens tested in this study. The combination SYNBIO® showed a microbicidal activity against most of the strains tested in the study. Conclusions Compared with the control, most of the pathogenic bacteria and yeast were inhibited by all probiotic strains tested to various degrees. Significance and Impact of the Study Screening Lactobacillus strains according to their activity in various environmental conditions could precede the clinical efficacy studies for adjunct treatment with probiotics in cure of different gastrointestinal and vaginal tract infections.

The effect of lactic acid bacteria on the serum cholesterol levels and the cecal microflora in rabbits fed dietary casein has been examined. A control group was fed a soybean protein diet, three other groups a casein diet; two of tho groups given casein were also given lyophilised resting cells of lactic acid bacteria: Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus to one group and Lactobacillus acidophilus to the other. After 42 d of the experimental diets the cecal content was subjected to microbiological analysis: there was no modification of microflora composition with regard to genera, however there were differences in cecal SCFA production and the frequency of the Bacteroides and Clostridium species. Moreover the high serum cholesterol levels found in the rabbits fed the casein diet were decreased after the administration of lactic acid bacteria, revealing the positive role of such bacteria. Our microbiological data underline the importance of diet on the growth and activity of the different bacteria species present in the intestinal ecosystem, and confirm the utility of lactic acid bacteria in restoring microflora balance.

An investigation was carried out to determine whether variations of dietary carbohydrates could modify the colonic flora in rats. Sprague-Dawley rats were fed with two equicaloric diets based on the AIN-76 diet (American Institute of Nutrition 1977) but differing from that diet in content of carbohydrates, i.e. high sucrose (64%) of high corn starch (64%). Feeding was continued for 9 months ad libitum and no variation in weight gain was recorded among the different diets. A prevalence of aerobes, and a significant reduction in the ratio anaerobes/aerobes in the faeces of rats on the high starch diet compared with the high sucrose diet, was observed. The anaerobe genera identified included Actinomyces, Bacteroides, Bifidobacterium, Clostridium, Eubacterium, Lactobacillus and Propionibacterium. Bacteroides was the most prevalent genus in both dietary groups (51.2 and 29.5% in the faeces of rats fed the sucrose and starch diets, respectively). In contrast, clostridia were prevalent in the starch-fed group (23.8%) and less so in the sucrose diet (11.5%), as propionibacteria were prevalent in faeces of rats fed the starch diet (15.5%), and low in the sucrose diet (3.9%). The remaining genera were scarce in faeces from rats on either diet. Total short-chain fatty acids (SCFA) were significantly higher in the faeces of animals fed the starch diet compared with those fed the sucrose diet. The relative concentrations of acetic, propionic and butyric acids were not significantly different between the two dietary groups. In conclusion, high starch diet can markedly modify the composition of faecal flora and alter considerably the faecal concentration of SCFAs, compound which might have a health-promoting effect.

Aims To test different Lactobacillus strains for their antipathogenic activity towards Candida strains and their adhesion properties for the preparation of vaginal ovules and douches to be used in vaginal candidiasis prevention. Methods and results Five strains of lactobacilli were tested for their antimicrobial potential against different clinically isolated Candida strains. They were also screened for their ability to produce hydrogen peroxide and to coaggregate with pathogens. Adhesion properties of the five different Lactobacillus strains to HeLa cells and the presence of arcA gene were also assessed. The in vitro experiments demonstrated that all the five Lactobacillus strains tested possessed inhibitory action against the Candida strains using the radial streak method, but the effect is strain dependent. The same situation arises with regard to the ability of coaggregation that is present in all the strains into different degrees. Only Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®) were able to produce H2O2 and none of the strains possess arcA gene. The most adherent strains to HeLa cells were Lact. rhamnosus IMC 501(®), Lact. paracasei IMC 502(®) and also their combination SYNBIO(®). This latter was selected for the preparation of ovules and douches using different matrix. Witepsol(®) ovules have proved the best formulation in terms of probiotic viability. Conclusions Lactobacillus rhamnosus IMC 501(®), Lact. paracasei IMC 502(®) and SYNBIO(®) were able to produce H2O2, to coaggregate and to exert antimicrobial activity against pathogenic Candida strains and to strongly adhere to HeLa cells. All these properties together with those technological make these strains good candidates for the realization of formulations suitable for vaginal health. Significance and impact of the study To develop new vaginal formulations taking into account the impact of probiotic strains on pathogens as well as the technological properties of the strains to validate their effectiveness in human health.

Fermented foods have a great significance since they provide and preserve large quantities of nutritious foods in a wide diversity of flavors, aromas and texture, which enrich the human diet. Originally fermented milks were developed as a means of preserving nutrients and are the most representatives of the category. The first aim of this study was to screen the effect of buckwheat flour and oat bran as prebiotics on the production of probiotic fiber-enriched fermented milks, by investigating the kinetics of acidification of buckwheat flour- and oat bran-supplemented milk fermented by Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their 1:1 combination named SYNBIO®. The probiotic strains viability, pH and sensory characteristics of the fermented fiber-enriched milk products, stored at 4 °C for 28 days were also monitored. The results showed that supplementation of whole milk with the tested probiotic strains and the two vegetable substrates results in a significant faster lowering of the pH. Also, the stability of L. rhamnosus IMC 501®, L. paracasei IMC 502® and SYNBIO® during storage at 4 °C for 28 days in buckwheat flour- and oat bran-supplemented samples was remarkably enhanced. The second aim of the study was to develop a new synbiotic product using the best combination of probiotics and prebiotics by promoting better growth and survival and be acceptable to the consumers with high concentration of probiotic strain. This new product was used to conduct a human feeding trial to validate the fermented milk as a carrier for transporting bacterial cells into the human gastrointestinal tract. The probiotic strains were recovered from fecal samples in 40 out of 40 volunteers fed for 4 weeks one portion per day of synbiotic fermented milk carrying about 10(9) viable cells.

The popularity of functional foods continues to increase as consumers desire flavorful foods that will fulfil their health needs. Among these foods, probiotics may exert positive effects on the composition of gut microbiota and overall health. However, in order to be beneficial, the bacterial cultures have to remain live and active at the time of consumption. The aim of this study was to develop new probiotic food products, such as seasoned cheeses, salami, chocolate and ice-cream with a final probiotic concentration of approximately 10⁹CFU/daily dose of Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® mixed 1:1 (SYNBIO®). The survival and viability of probiotics were determined during the foods shelf-life. The values of viable probiotic bacteria of all dairy and non-dairy foods were between 10⁷ and 10⁹CFU/g of food at the end of the shelf-life and for some of them the values were maintained even after the expiry date. Based on the results of the current study, all the dairy ("Caciotta" cheese, "Pecorino" cheese, "Büscion" Swiss cheese and "Fiordilatte" ice-cream) and non-dairy ("Ciauscolo" salami, Larded salami, Swiss small salami, milk chocolate, dark chocolate, organic jam and chocolate mousse) food products studied would be excellent vehicles to deliver the probiotic health effects because of the high viability of probiotics during the shelf-life of foods and in some cases even after their expiry date.

The functional food industry requires an improvement of probiotic strain stability during storage, especially when they are stored at room temperature. In this study, the viability of freeze-dried Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®) using different protective agents (i.e., glycerine, mannitol, sorbitol, inulin, dextrin, Crystalean(®)) was determined and compared with semi skimmed milk (SSM) control. No significant differences were observed between the tested protectants and the control (SSM) during storage at refrigerated conditions. During storage at room temperature, only glycerine was found to stabilize viability better than other tested substances.

The present study aimed to test the effects of probiotic treatment on gut microbiota and the contribution to the well-being of European sea bass (Dicentrarchus labrax, L.). A bacterial strain of Lactobacillus delbrueckii subsp. delbrueckii (AS13B), isolated from adult European sea bass gut, was administered during sea bass development using Brachionus plicatilis and/or Artemia salina as carriers. The effective strain colonization and modulation of the gut microbiota, the mortality and the cortisol levels of sea bass were monitored during early developmental stages. The L. delbrueckii subsp. delbrueckii strain showed good capability to colonize the gut of sea bass larvae, therefore modifying the gut microbiota, and exerting positive effects on the survival of the treated sea bass. L. delbrueckii subsp. delbrueckii as a probiotic dietary supplement represents an advantageous and ecological strategy for improving the health of fish in aquaculture and increasing fish production.Key words: Lactobacillus delbrueckii subsp. delbrueckii, probiotic strain, Dicentrarchus labrax, aquaculture, gut microbiota, mortality, stress

A cross-sectional study on intestinal microbiota composition was performed on 230 healthy subjects at four European locations in France, Germany, Italy, and Sweden. The study participants were assigned to two age groups: 20 to 50 years (mean age, 35 years; n = 85) and >60 years (mean age, 75 years; n = 145). A set of 14 group- and species-specific 16S rRNA-targeted oligonucleotide probes was applied to the analysis of fecal samples by fluorescence in situ hybridization coupled with flow cytometry. Marked country-age interactions were observed for the German and Italian study groups. These interactions were inverse for the predominant bacterial groups Eubacterium rectale-Clostridium coccoides and Bacteroides-Prevotella . Differences between European populations were observed for the Bifidobacterium group only. Proportions of bifidobacteria were two- to threefold higher in the Italian study population than in any other study group, and this effect was independent of age. Higher proportions of enterobacteria were found in all elderly volunteers independent of the location. Gender effects were observed for the Bacteroides-Prevotella group, with higher levels in males than in females. In summary, age-related differences in the microbiota makeup were detected but differed between the study populations from the four countries, each showing a characteristic colonization pattern.

The Mediterranean diet, rich in fruits, vegetables, and grains as well as olive oil and olives, has been associated with a lower risk of coronary heart disease and cancer. The beneficial role of olive oil has been related to its fatty acid composition and the presence of phenolic compounds. The present research aimed to study the biological activity of some olive oil iridoids, such as hydroxytyrosol and tyrosol, as microbial inhibitors and their in vitro effects on modulation of human intestinal microflora. Among the tested strains, Bifidobacterium longum , Lactobacillus salivarius , and Bacteroides vulgatus showed the highest sensitivity to the tested compounds; however, the inhibitory effect of iridoids seemed to be more effective when a mix of olive oil iridoids, instead of pure hydroxytyrosol, was used. The fermentation experiments showed that olive oil iridoids modulate the intestinal microflora, leading to a higher production of total short chain fatty acids and in particular of butyrate. These are important conditions well known to be associated with a protective effect against colon cancer development. Key words: olive oil iridoids, hydroxytyrosol, intestinal microflora, semi-continuous culture system

The main source of carbon in the human large intestine comes from carbohydrates like starches and oligosaccharides which remain unchanged by gastric digestion. These polysaccharides are metabolised in the colon by saccharolytic bacteria whose composition is dependent upon the substrate availability. Among the metabolites produced, the short-chain fatty acids (SCFA) are important for colon function and to prevent diseases. In particular, butyrate affects several cellular functions (proliferation, membrane synthesis, sodium absorption), and it has been shown to be protective against colorectal cancer. In addition, faecal bacteria are responsible for the conversion of primary bile acids (BA) to secondary BA, which are considered tumor promoters. In this study we investigated the in vitro effect of different substrates (CrystaLean starch, xylo-oligosaccharides, corn starch) supplied to human faecal micro-flora, on the SCFA production, on the bowel micro-flora composition and on the primary BA conversion rate. In addition, with corn starch as substrate, we considered the effect of enriching normal human faecal micro-flora with lactobacilli and bifidobacteria, on the above reported parameters.

Aims: The aims of the present study were to: (i) analyse a group of antimicrobial agents and to select the most active against test microbial strains; (ii) test the effect of the antimicrobial treatment on air filters in order to reduce microbial colonization. Methods and Results: Different kinds of antimicrobial agents were analysed to assess their compatibility with the production process of air filter media. The minimal inhibitory concentration for each antimicrobial agent was determined against a defined list of microbial strains, and an antimicrobial activity assay of filter prototypes was developed to determine the most active agent among the compatible antimicrobials. Then, the most active was chosen and added directly to the filter during the production process. The microbial colonization of treated and untreated filter media was assessed at different working times for different incubation times by stereomicroscope and scanning electron microscope analysis. Some of the antimicrobial agents analysed were more active against microbial test strains and compatible with the production process of the filter media. Filter sections analysis of treated filter media showed a significantly lower microbial colonization than those untreated, a reduction of species both in density and varieties and of the presence of bacteria and fungal hyphae with reproductive structures. Conclusions: This study demonstrated the ability of antimicrobial treatments to inhibit the growth of micro-organisms in filter media and subsequently to increase indoor air quality (IAQ), highlighting the value of adding antimicrobials to filter media. Significance and Impact of the Study: To make a contribution to solving the problem of microbial contamination of air filters, by demonstrating the efficacy of incorporating antimicrobial agents in the filter media to improve IAQ and health.

We studied whether repeated boluses of sucrose or diets containing carbohydrates with a variable glycemic index (GI) affect intestinal carcinogenesis in rats. Male F344 rats were treated twice (1 wk apart) with 15 mg/kg sc azoxymethane (AOM) and then divided into four experimental dietary groups with different carbohydrate composition and administration schedules: the sucrose group was fed 44% (wt/wt) sucrose (GI = 65), the bolus group was fed sucrose as carbohydrate and 43 boluses of sucrose (10-15 g/kg) at various time intervals, the pasta group was fed pasta [77% (wt/wt) cooked pasta, GI = 55], and the glucose group was fed 44% (wt/wt) glucose (GI = 97). All nutrients, including carbohydrates, were provided in similar amount to the different groups. The experiment was terminated between Day 230 and Day 245 after AOM administration. At this time the pasta group had significantly higher cecal short-chain fatty acids than the other groups. Intestinal adenomas and cancers occurred with the same frequency in the bolus, sucrose, and glucose groups. On the contrary, we observed a significant decrease (p = 0.03) in the cumulative incidence of intestinal adenomas, but not adenocarcinomas, in the pasta group compared with the sucrose group (intestinal adenoma incidence in the pasta group was 31% compared with 63% in the sucrose group, 46% in the bolus group, and 37% in the glucose group). In conclusion, these results do not support the hypothesis that sucrose boluses or carbohydrates with a high GI stimulate colon carcinogenesis, but they indicate that foods such as pasta may exert a protective effect.

Summary Forty-six strains representing species of the genus Clostridium, known to contain nuclear dehydrogenating members, were studied by conventional tests and by gas-liquid chromatographic analysis of the end-products of carbohydrate fermentation. The DNA base composition of the strains was also determined. The conventional data were analyzed by the simple matching coefficient (SsM) and the fermentation endproduct data by the degree of overlap between superimposed traces (SO). Clustering was by the unweighted average pair group method (UPGMA). The resulting phenograms showed remarkable differences between the clustering of the strains depending on whether data based on SsM or SO coefficients were used. The SsM phenogram showed that four of the five clusters contained strains belonging to the same species (C. tertium, C. sphenoides, C. sporogenes, C. bifermentans), and one cluster contained strains from two species (C. paraputrificum and C.butyricum), whereas only one strain (C. indolis) was not included in any cluster. The variability in the range of G+C base composition was less than 4% in four clusters and ranged from 26 to 53 mol% G+C in another cluster. The SO phenogram gave nine clusters. In seven of these, strains from the same named species (C. butyricum, C. sporogenes and C. bifermentans) were sub-divided into more than one cluster and in the two remaining clusters there were strains from two different species: C. tertium with C. paraputrificum in one and C. sphenoides with C. indolis in the other. The range of DNA base composition for strains within the clusters did not exceed 5 mol%.

Polyphenols from tea and other beverages such as red wine have been regarded with interest as possible chemopreventive agents against cancer. Here we report that red wine polyphenols (50 mg/kg) administered with the diet to F344 rats for 16 weeks inhibited colon carcinogenesis induced by azoxymethane (AOM, 7.4 mg/kg, total dose 74 mg/kg) or dimethylhydrazine (DMH, 30 mg/kg, total dose, 300 mg/kg). Polyphenol-treated animals had a consistently lower tumour yield compared to controls. In polyphenol-treated rats, the main bacterial strains in the faeces at sacrifice were Bacteroides, Lactobacillus and Bifidobacterium spp., whereas microorganisms predominantly identified in control-fed rats were Bacteroides, Clostridium and Propionibacterium spp. Wine polyphenols (57 mg/kg for 10 days, by gavage), administered to rats not treated with carcinogens, produced a significant decrease in the basal level of DNA oxidative damage of the colon mucosa as measured with the comet assay (average pyrimidine oxidation was reduced by 62% and purine oxidation by 57%, p