Metagenomic and volatile profiles of ripened cheese obtained from dairy ewes fed a dietary hemp seed supplementation.

Chemical and organoleptic properties of dairy products largely depend on the action of microorganisms that tend to be selected in cheese during ripening in response to the availability of specific substrates. The aim of this work was to evaluate the effects of a diet enriched with hemp seeds on the microbiota composition of fresh and ripened cheese produced from milk of lactating ewes. Thirty-two half-bred ewes were involved in the study, in which half (control group) received a standard diet, and the other half (experimental group) took a diet enriched with 5% hemp seeds (on a DM basis) for 35 d. The dietary supplementation significantly increased the lactose in milk, but no variations in total fat, proteins, caseins, and urea were observed. Likewise, no changes in total fat, proteins, or ash were detected in the derived cheeses. The metagenomic approach was used to characterize the microbiota of raw milk and cheese. The phyla Proteobacteria and Firmicutes were in equally high abundance in both control and experimental raw milk samples, whereas Bacteroidetes was less abundant. The scenario changed when considering the dairy products. In all cheese samples, Firmicutes was clearly predominant, with Streptococcaceae being the most abundant family in the experimental group. The reduction of taxa observed during ripening was in accordance with the increment (relative abundance) of the starter culture Lactococcus lactis and Streptococcus thermophilus, which together dominate the microbial community. The analysis of the volatile profile in ripened cheeses led to the identification of 3 major classes of compounds: free fatty acids, ketones, and aldehydes, which indicate a prevalence of lipolysis compared with the other biochemical mechanisms that characterize the cheese ripening.

Gut microbiota of preterm infants supplemented with probiotics: sub-study of the ProPrems trial.

BACKGROUND: The ProPrems trial, a multi-center, double-blind, placebo-controlled randomized trial, previously reported a 54% reduction in necrotizing enterocolitis (NEC) of Bell stage 2 or more from 4.4 to 2.0% in 1099 infants born before 32 completed weeks' gestation and weighing < 1500 g, receiving probiotic supplementation (with Bifidobacterium longum subsp. infantis BB-02, Streptococcus thermophilus TH-4 and Bifidobacterium animalis subsp. lactis BB-12). This sub-study investigated the effect of probiotic supplementation on the gut microbiota in a cohort of very preterm infants in ProPrems. RESULTS: Bifidobacterium was found in higher abundance in infants who received the probiotics (AOR 17.22; 95% CI, 3.49-84.99, p < 0.001) as compared to the placebo group, and Enterococcus was reduced in infants receiving the probiotic during the supplementation period (AOR 0.27; 95% CI, 0.09-0.82, p = 0.02). CONCLUSION: Probiotic supplementation with BB-02, TH-4 and BB-12 from soon after birth increased the abundance of Bifidobacterium in the gut microbiota of very preterm infants. Increased abundance of Bifidobacterium soon after birth may be associated with reducing the risk of NEC in very preterm infants.

Antibacterial activity of selenium-enriched lactic acid bacteria against common food-borne pathogens in vitro.

Selenium (Se) is an essential trace element for human health and animal nutrition. The aim of this study was to evaluate the inhibitory activities of Se-enriched lactic acid bacteria (LAB), Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus, against pathogenic Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes in vitro. The results indicated that the accumulation amount of Se by Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus reached 12.05 ± 0.43 µg/mL and 11.56 ± 0.25 µg/mL, respectively, accompanied by the relative maximum living cells when sodium selenite was 80 µg/mL. Oxford cup double plate assay showed that bacterial culture solution and cell-free culture supernatant (CFCS) from Se-enriched LAB exerted stronger antibacterial activity than those from the non-Se strains. The growth of pathogenic bacterial culture with CFCS at any growth stages was worse than that without CFCS; moreover, the inhibiting effect of CFCS of Se-enriched LAB was more significant than that of non-Se strains. Results from a scanning electron microscope equipped with energy dispersion X-ray spectrometry showed that elemental Se nanoparticles, which characteristically energy peak around 1.42 keV, were deposited on the cell surfaces of Lactobacillus delbrueckii ssp. bulgaricus. In addition, CFCS of Se-enriched LAB induced more serious cell structure damage of pathogenic bacteria than did non-Se LAB.

Impact of multi-functional fermented goat milk beverage on gut microbiota in a dynamic colon model.

The aim of this research was to evaluate the effect of grape probiotic fermented beverages made of goat milk, with or without added grape pomace on gut microbiota in a Simulator of Human Intestinal Microbial Ecosystem (SHIME®). SHIME® model was used to investigate to assess changes in microbial composition and fermentation metabolites (short- and branched-chain fatty acids and ammonium), as well as under the antioxidant capacity. The results demonstrated that the beverages formulated, with or without grape pomace extract, exhibited high dietary fiber, oleic acid, phenolic compounds content and antioxidant activity. Both beverages also kept L. rhamnosus and S. thermophilus viable during their passage through the intestinal tract and had a positive effect on gut microbiota metabolism, increasing the antioxidant capacity and the production of short-chain fatty acids, and decreasing the ammonium concentration. Therefore, the multifunctional beverages formulated in this study can offer a new perspective for the production of foods with positive potential effects on human health.

Streptococcus thermophilus NCIMB 41856 ameliorates signs of colitis in an animal model of inflammatory bowel disease.

Treatment of inflammatory bowel disease (IBD) is mainly based on suppression of symptoms, often with numerous side effects. Trials of probiotics in IBD have frequently produced disappointing results. The majority of probiotics are unusual, since they do not require iron for growth, unlike many bacteria resident in the intestine. The IBD intestine is iron-rich due to bleeding and use of oral iron supplements; conventional probiotics would be rapidly outcompeted. We have evaluated an iron-responsive Streptococcus thermophilus strain for its potential to reduce signs of colitis. Efficacy of S. thermophilus was evaluated in the dextran sodium sulphate mouse model of colitis. Treated animals were given 1×108 cfu S. thermophilus per day and clinical observations were taken daily. At termination, gross and histopathological signs of disease, cellular infiltration, location of bacteria, and cytokine expression in the intestine were determined. S. thermophilus delayed onset of colitis and reduced clinical signs of disease, including bodyweight loss and gastrointestinal bleeding. It reduced bacterial translocation into the colonic tissue. Increased numbers of CD8+ intraepithelial lymphocytes were seen in control animals treated with S. thermophilus. S. thermophilus had no effect on gross pathology, histopathology or cytokine production in either colitic or control animals. We propose that S. thermophilus promotes maintenance of mucosal barrier function which reduces bacterial translocation, thereby reducing immune stimulation and associated inflammation. This allows mucosal healing, reducing gastrointestinal bleeding and weight loss. This could be studied as a locally-acting adjunct or alternative to current IBD treatments.

In vitro and in vivo antagonistic activity of new probiotic culture against Clostridium difficile and Clostridium perfringens.

BACKGROUND: Genus Clostridium accompanies more than 200 known species and at least 30 among them are associated with human and animal diseases. At the moment, the treatment of clostridial infections is based on use of antibiotics. However, due to the European ban on the use of antibiotics in livestock production, novel therapeutic strategies for treatment of these hardly curable infections have been evaluated. Hence, in this study the antimicrobial effect of newly designed probiotic culture consisted of natural isolates Lactobacillus helveticus BGRA43, Lactobacillus fermentum BGHI14 and Streptococcus thermophilus BGVLJ1-44 against Clostridium difficile and Clostridium perfringens was analyzed. RESULTS: The probiotic culture showed strong in vitro antimicrobial effect on C. difficile (human clinical isolate). In addition, individual strains and the probiotic combination exhibited immunomodulatory activity. The probiotic combination significantly increased the proliferation of GALT lymphocytes. At the other hand, none of the bacterial treatments (individual strains and the combination) induced the production of proinflammatory cytokines IL-6 and IL-1ß by intestinal epithelial cells, Caco-2. Interestingly, Caco-2 cells exposed to the probiotic combination produced significantly elevated amount of TGFß pointing to potential protecting effect of the probiotic. In addition, the results of field trial on spontaneously infected goats revealed reduction of C. perfringens in goats (below the detection threshold) after the probiotic treatment. CONCLUSIONS: The results of this study indicated that the novel probiotic deserves to be further investigated as a promising antimicrobial agent against C. difficile and C. perfringens.

Acid production and conversion of konjac glucomannan during in vitro colonic fermentation affected by exogenous microorganisms and tea polyphenols.

Impacts of exogenous microorganisms and tea polyphenols on acid production and conversion during in vitro colonic fermentation of konjac glucomannan (KGM) were assessed in this study. Colonic fermentation of KGM by the fecal extract of healthy adults resulted in a propionate-rich profile, as acetic, propionic, butyric and lactic acids production were 16.1, 13.0, 3.3 and 20.2 mmol/L, respectively. Inoculation of one of ten exogenous microorganisms in the fermentative systems increased acetic, propionic and butyric acids production by 50-230%, 9-190% and 110-350%, respectively, and also accelerated lactic acid conversion by 14-40%. Tea polyphenols in the fermentative systems showed clear inhibition on both acid production and conversion; however, this inhibition could be partially or mostly antagonised by the inoculated exogenous microorganisms, resulting in improved acid production and conversion. In total, Lactobacillus brevis and Sterptococcus thermophilus were more able to increase acid production, and the propionate-rich profile was not changed in all cases.

Fermented infant formulas without live bacteria: a systematic review.

UNLABELLED: Fermented formulas, i.e., those fermented with lactic acid-producing bacteria during the production process and not containing significant amounts of viable bacteria in the final product, are widely available in many countries. Our aim was to systematically review published evidence related to the safety and health effects of the administration of fermented infant formulas compared with standard infant formulas. The Cochrane Library, MEDLINE, and EMBASE databases and major pediatric conference proceedings were searched. Five randomized controlled trials (RCTs) involving 1326 infants met the inclusion criteria. Compared with standard formula, the use of fermented formula resulted in a similar weight gain and length gain during the study period. Data from one RCT, albeit large, suggest the effectiveness of fermented formula in preventing and treating acute diarrhea. Fermented formula has the potential to reduce some, albeit not well-defined, digestive symptoms. Current evidence does not support the use of fermented formula for preventing cow's milk allergy. CONCLUSION: Limited available evidence suggests that the use of fermented infant formula, compared with the use of standard infant formula, does not offer clear additional benefits, although some benefit on gastrointestinal symptoms cannot be excluded. What is known • Fermented formulas, i.e., those fermented with lactic acid-producing bacteria during the production process and not containing significant amounts of viable bacteria in the final product, are widely available in many countries. What is new • Limited evidence available suggests that the use of fermented infant formula, compared with the use of standard infant formula, does not offer clear additional benefits, although some benefit on gastrointestinal symptoms cannot be excluded. At the same time, no negative health effects have been documented.

[Investigation of the effects of probiotic bacteria on bacterial translocation that developed during diagnostic laparoscopy: an experimental study]. / Tanisal Amaçla Uygulanan Laparoskopi Sirasinda Olusan Bakteriyel Translokasyona Probiyotik Bakterilerin Etkilerinin Arastirilmasi: Deneysel Bir Çalisma.

Probiotics which are non-pathogenic live microorganisms ingested along with food or as dietary supplements, are thought to be beneficial to the host by supporting the microbial balance in digestive system. Various studies suggest that the effects of probiotics on the intestinal mucosa and immunity are protective against bacterial translocation. We aimed to investigate bacterial translocation related to the amount of CO2 insufflation given during laparoscopy and the effect of probiotic bacteria in an experimental peritonitis model. In this study 60 Wistar rats were used in six groups consisting of 10 rats. Group 1, 3 and 5 consisted of the rats that were fed without probiotics, while the rats in Group 2, 4, and 6 were fed with water containing 5 x 108 cfu/ml probiotic bacteria complex (Bifidobacterium lactis, Lactobacillus bulgaricus, Streptococcus thermophilus) for 15 days. To generate experimental peritonitis, 2 x 107 cfu/ml Escherichia coli ATCC 25922 was inoculated intraperitoneally to all of the rats. Thereafter, laparoscopy was applied in all groups. Application in Group 1 and Group 2 was without CO2; Group 3 and Group 4 with 14 mmHg CO2 insufflation, and Group 5 and Group 6 with 20 mmHg CO2 insufflation. Blood samples were taken in 2nd, 4th, and 6th hours. Mesenteric lymph node, liver and spleen samples were taken at 6th hour when the rats were sacrificed and then these were evaluated microbiologically with qualitative and quantitative methods. Bacterial translocation and bacteremia were found in the rats that were undergone experimental peritonitis during laparoscopy. All positive tissue and blood cultures yielded E.coli. The highest level of bacterial translocation was found to be in mesenteric lymph nodes (in 3/10, 6/10 and 10/10 in groups 1, 3 and 5 fed without probiotics, respectively; in 2/10, 3/10 and 4/10 in groups 2, 4 and 6 fed with probiotics, respectively). The bacterial translocation rates were found to be related to the increased CO2 insufflation. It was found that probiotic bacteria were more effective for decreasing bacterial translocation rates and bacteremia in the groups that were given high CO2 pressure during laparoscopy. It was also found that these results were correlated with bacterial translocation per gram of tissue. As an example, the quantitative bacterial growth values detected in mesenteric lymph node were 5.4 ± 2.9 x 103, 10.6 ± 3.3 x 103 and 21.5 ± 12.4 x 103 cfu/g in groups 1, 3 and 5, fed without probiotics, respectively; and 2.0 ± 1.3 x 103, 3.8 ± 1.9 x 103 and 9.0 ± 3.1 x 103 cfu/g in groups 2, 4 and 6, fed with probiotics, respectively. Our data emphasized that probiotic bacteria may be used as prophylactic agents for the prevention of bacterial translocation during laparoscopy, however comprehensive and clinical studies are needed to support these experimental results.

Selenium-enriched probiotics improves murine male fertility compromised by high fat diet.

A total of 75 male mice were allotted to five groups of 15 each in a completely randomized experimental design to study the effects of probiotics, inorganic selenium, and selenium-enriched probiotics on male fertility in hyperlipidemic status. The mice in group 1 were fed a normal basal diet and served as negative control. The mice in group 2 were fed a high fat diet and served as positive control. The mice in groups 3, 4, and 5 were fed the high fat diet supplemented with probiotics, inorganic selenium, and selenium-enriched probiotics, respectively. The high fat diet was composed of 15% lard, 1% cholesterol, 0.3% cholic acid, and 83.7% basal diet. Over 90% of the selenium in the selenium-enriched probiotics was present in forms of organic selenium. After the mice were fed these diets for 75 days, serumal total cholesterol, triglycerides, low density lipoprotein, high density lipoprotein, and testosterone levels, plus sperm index (count, motility and abnormalities), penis length, and weight and histopathology of testes were measured. The results showed that in the mice fed the high fat diet were significant (P < 0.01) elevations of serumal total cholesterol, triglycerides and low density lipoprotein, and decreases of high density lipoprotein. The high fat diet caused a decline in serumal testosterone level, reduced semen quality, and atrophy and degeneration of seminiferous tubules. No effects on penis length or relative weight of testis were observed. Supplementation of probiotics, inorganic selenium, or selenium-enriched probiotics to the high fat diet significantly alleviated (P < 0.05) the adverse effects of hyperlipidemia by reducing testicular tissue injury, increasing serumal testosterone level, and improving sperm indexes. It was concluded that hyperlipidemia had significant adverse effects on male fertility, which could be ameliorated at various degrees by feeding the diets supplemented with probiotics, inorganic selenium, or selenium-enriched probiotics. Selenium-enriched probiotics or inorganic selenium supplementation gave better results than probiotics supplementation and may be used to improve animal and human male fertility compromised by hyperlipidemia or obesity.

Beneficial effects of a synbiotic supplement on self-perceived gastrointestinal well-being and immunoinflammatory status of healthy adults.

The use of synbiotics as health promoters is still poorly defined, and human intervention studies are scarce. This study was designed to evaluate the effects of a commercialized synbiotic product containing Lactobacillus acidophilus La5, Bifidobacterium animalis ssp. lactis Bb-12, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus paracasei ssp. paracasei, Streptococcus thermophilus, and fructooligosaccharides on the self-reported gastrointestinal well-being and the immunoinflammatory status of healthy human subjects. In this randomized, double-blind, placebo-controlled study, 20 women and 16 men (25-45 years old) received either three tablets per day of the synbiotic product (2.4 × 10(9) colony-forming units/day) or placebo during 6 weeks. Gastrointestinal symptoms and bowel habits were evaluated through a self-administered questionnaire. In those subjects suffering from any kind of digestive disturbance (mild dyspepsia, flatulence, postprandial bloating, constipation, etc.), improvements in symptoms after product consumption were also evaluated. Blood lymphocyte subsets, phagocytic activity, serum C-reactive protein, ceruloplasmin, and adhesion molecules concentrations were analyzed prior and after treatment. A significant improvement in overall self-reported gastrointestinal symptoms and bowel habit was found in the synbiotic group. A marginal effect of treatment (analysis of variance P = .050) was observed with L-selectin, which showed a significant decrease in the synbiotic group (P = .019). In addition, basal L-selectin levels correlated with final intercellular adhesion molecule (ICAM)-1 levels (r = 0.468; P = .050), and basal ICAM-1 levels tended to correlate negatively with final L-selectin concentration (r = -0.457; P = .056). None of these correlations was found in the placebo group. The rest of the immunological parameters studied were not modified by the intervention. In conclusion, consumption of the synbiotic product improves self-perceived bowel habits and might facilitate a better profile of adhesion molecules in healthy adults.

Beta-galactosidase production by Streptococcus thermophilus is higher in the small intestine than in the caecum of human-microbiota-associated mice after lactose supplementation.

Transit kinetics and survival rates of a bacterial species from yoghurt (i.e. Streptococcus thermophilus strain FBI3) were examined in different digestive compartments of gnotoxenic and human-microbiota-associated mice. The production of the lactose-hydrolysing enzyme (i.e. beta-galactosidase) was also investigated within the digestive tract, using a chromosomal reporter system based on luciferase genes from Photorhabdus luminescens under the control of the plac promoter. In both mice models, S. thermophilus cells transited within 2 h from the stomach to the caecum-colon compartment of the digestive tract where they displayed a survival rate of nearly 100 %. In gnotoxenic mice, luciferase activity was found to increase in the second half of the small intestine and in the caecum-colon compartment when lactose was added to the drinking water provided to the animals. In human-microbiota-associated mice drinking lactose, luciferase activity was similarly increased in the second half of the small intestine but was drastically reduced in the caecum-colon compartment. This feature could be ascribed to the presence of the resident human microbiota.