The role of probiotic cultures in the control of gastrointestinal health

Use of pro-/synbiotics as prophylaxis in patients undergoing colorectal resection for cancer: a meta-analysis of randomized controlled trials

AIMS

To estimate the efficacy of pro-/synbiotics treatment in patients undergoing colorectal resection, a meta-analysis of randomized controlled trials was conducted.

METHODS

An electronic search of PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Academic Search Premier, and China National Knowledge Infrastructure was performed, and RevMan 5.0 was used for statistical analysis.

RESULTS

Six studies including 361 patients undergoing elective colorectal surgery were retrieved. The combined analysis revealed that perioperative pro-/synbiotics administration had a positive effect on the incidence of diarrhea (OR 0.29, 95% CI 0.14 to 0.62, P=0.001), the incidence of symptomatic intestinal obstructions (OR 0.39, 95% CI 0.19 to 0.78, P=0.008), the incidence of operative total infections (OR 0.39, 95% CI: 0.22 to 0.68, P=0.0010), and pneumonia infection (OR 0.32, 95% CI 0.11 to 0.93, P=0.04). The regimen increased the numbers of Lactobacillus (MD 2.66, 95% CI: 2.13 to 3.18; P<0.00001), and decreased the counts of Enterobacteriaceae (MD -1.52, 95% CI: -1.93 to -1.11, P<0.00001). No significant differences were found between the two groups in septic morbidity, incision infection, perineal infection, intraabdominal infection, anastomotic leak, the first defecation time, length of hospital stay, mesenteric lymph nodes for bacterial translocation. No mortality related to pro-/synbiotics treatment was revealed in all studies.

CONCLUSIONS

Based on the meta-analysis, perioperatively use pro-/synbiotics as prophylaxis in patients undergoing colorectal resection improved clinical outcomes. The best preventive strategy (including species and the optimal dose) of pro-/synbiotics should be considered in future meta-analyses.

Influence of diets to Wistar rats supplemented with soya, flaxseed and lupine products treated by lactofermentation to improve their gut health

The present study proposes the contribution of lactic acid bacteria and plants rich in bioactive substances and high-quality proteins as alternative products for human diets in improving the gut environment as potential against pathogenic bacteria. The effect of diets supplemented with soya, flaxseed and lupine flours fermented with a Pediococcus acidilactici KTU05-7 probiotic strain in the gastrointestinal tract (GIT) of Wistar rats were analyzed. In vivo experiments showed a positive effect of long time lactofermentation of plant material on the body weight of rats. Diets with fermented yellow lupine resulted in enhanced activities of α-glucosidase, β-galactosidases, as well as high levels of lactic acid bacteria, bifidobacteria and enterococci in the GIT were determined. Lactofermentation of analyzed plant products had a significantly lowering effect on Escherichia coli compared with the control group. The dominant flora of large intestines like Bifidobacterium and anaerobic cocci were found in high levels after diets with fermented lupine.

The effect of the probiotics Bacillus subtilis (PB6) on the selected indicators of the table eggs quality, fat and cholesterol

The aim of this study was to determine the effect of dietary probiotics Bacillus subtilis (PB6) on egg weigh, egg mass weigh, egg fat content and cholesterol content in egg yolk in laying hens ISA Brown during two experiments. The probiotics where supplied to the laying hens for 42 days as preparation period before eggs samples collection. The eggs samples were collected during 6 days for the 1st and 2nd experiments after the hens reached the age of 34 and 61 weeks, respectively.  A total of 36 ISA Brown laying hens were divided into 2 treatment groups. Control group laying hens were fed a basal diet with no probiotic added. In group Bacillus subtilis, the basal diet was supplemented with the bacteria Bacillus subtilis (PB6) at 1 g/kg, min. 2.3*108 cfu/g. Dietary treatments did not significantly affect the egg weigh, internal egg content weigh, cholesterol content expressed by g/100 g of egg yolk.  Bacillus subtilis (PB6) supplementation significantly (p < 0.05) increased the fat content in the internal egg content and cholesterol content in egg yolk expressed as g/pc. 

Effects of microencapsulated Enterococcus fecalis CG1.0007 on growth performance, antioxidation activity, and intestinal microbiota in broiler chickens

We performed a series of trials to assess the effect of dietary supplementation with microencapsulated Enterococcus fecalis CG1.0007 on growth performance, antioxidation activity, and intestinal microbiota in Arbor Acres broiler chickens ("broilers"). A total of 150 1-d-old broilers were assigned randomly to 5 feeding treatments (a control group fed the basal diet, 3 groups fed the basal diet plus various concentrations of microencapsulated CG1.0007, and 1 group fed the basal diet plus an antibiotic). Changes in important genera of intestinal bacteria were studied using 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis (DGGE) profiling and real-time quantitative PCR analysis of fecal samples. During the course of the 42-d experimental period, ADG of the birds fed the high and intermediate concentrations of microcapsules were significantly greater (9.90 and 9.50%, respectively) and the ratios of feed to gain fed were significantly lower (4.40 and 4.00%, respectively) compared with the control group. The total antioxidant capacity and the content of malondialdehyde and superoxide dismutase in the microcapsule-treated groups showed significant changes in terms of antioxidation. The numbers of Lactobacillus and Bifidobacterium were significantly greater in the microcapsule-treated groups than in the control group. Cluster analysis indicated that the DGGE bacterial profiles were related to the feeding treatments and revealing the diversity and richness of the intestinal microbiota associated with supplementation of microcapsules. In summary, our results indicate that dietary addition of microencapsulated E. fecalis CG1.0007 enhanced the growth performance of the broilers and improved their health.

A double-blind placebo-controlled randomized trial on probiotics in small bowel bacterial overgrowth in children treated with omeprazole

OBJECTIVE

To evaluate the incidence of small bowel bacterial overgrowth (SBBO) in children treated with omeprazole, and to test whether probiotics influence the incidence.

METHODS

A double-blinded, placebo-controlled trial was performed in 70 children treated orally during four weeks with 20mg omeprazole per day. Lactobacillus rhamnosus R0011 (1.9×10(9) cfu) and Lactobacillus acidophilus R0052 (0.1×10(9) cfu) were simultaneously given daily to 36 subjects (probiotic group), while 34 subjects received placebo (placebo group). The diagnosis of SBBO was based on the development of suggestive symptoms, in combination with a positive glucose breath test.

RESULTS

After one month of proton pump inhibitor (PPI) treatment, 30% (21/70) had a positive breath test suggesting SBBO; of these 62% were symptomatic. Five children developed SBBO-like symptoms, but had a negative breath test; and 44 (63%) were symptom free and had a negative breath test. There was no difference in the incidence of positive breath tests in the probiotic versus the placebo group (33% vs 26.5%; p=0.13).

CONCLUSIONS

Since symptoms suggesting SBBO developed in 26% of PPI-treated children, and since the glucose breath test was abnormal in 72% of these, this side-effect should be more frequently considered. The probiotic tested did not decrease the risk to develop SBBO.

Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children

BACKGROUND

Antibiotics are widely prescribed; however they can cause disturbances in gastrointestinal flora which may lead to reduced resistance to pathogens such as Clostridium difficile (C. difficile). Probiotics are live organisms thought to balance the gastrointestinal flora.

OBJECTIVES

The primary objectives were to assess the efficacy and safety of probiotics for preventing Clostridium difficile-associated diarrhea (CDAD) or C. difficile infection in adults and children.

SEARCH METHODS

On February 21, 2013 we searched PubMed (1966-2013), EMBASE (1966-2013), Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 1), CINAHL (1982-2013), AMED (1985-2013), and ISI Web of Science. Additionally, we conducted an extensive grey literature search including contact with industry representatives.

SELECTION CRITERIA

Randomized controlled (placebo, alternative prophylaxis, or no treatment control) trials investigating probiotics (any strain, any dose) for prevention of CDAD, or C. difficile infection were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently and in duplicate extracted data and assessed risk of bias using pre-constructed, and piloted, data extraction forms. Any disagreements were resolved by a third adjudicator. For articles published in abstract form only, further information was sought by contacting principal authors. The primary outcome was the incidence of CDAD. Secondary outcomes included the incidence of C. difficile infection, adverse events, antibiotic-associated diarrhea (AAD) and length of hospital stay. Dichotomous outcomes (e.g. incidence of CDAD) were pooled using a random-effects model to calculate the relative risk and corresponding 95% confidence interval (95% CI). Continuous outcomes (e.g. length of hospital) were pooled using a random-effects model to calculate the mean difference and corresponding 95% CI. Sensitivity analyses were conducted to explore the impact of missing data on efficacy and safety outcomes. For the sensitivity analyses, we assumed that the event rate for those participants in the control group who had missing data was the same as the event rate for those participants in the control group who were successfully followed. For the probiotic group we calculated effects using the following assumed ratios of event rates in those with missing data in comparison to those successfully followed: 1.5:1, 2:1, 3:1, and 5:1. To explore possible explanations for heterogeneity, a priori subgroup analysis were conducted on probiotic species, dose, adult versus pediatric population, and risk of bias.The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

A total of 1871 studies were identified with 31 (4492 participants) meeting eligibility requirements for our review. Overall 11 studies were rated as a high risk of bias due mostly to missing outcome data. A complete case analysis (i.e. participants who completed the study) of those trials investigating CDAD (23 trials, 4213 participants) suggests that probiotics significantly reduce this risk by 64%. The incidence of CDAD was 2.0% in the probiotic group compared to 5.5% in the placebo or no treatment control group (RR 0.36; 95% CI 0.26 to 0.51). Sixteen of 23 trials had missing CDAD data ranging from 5% to 45%. These results proved robust to sensitivity analyses of plausible and worst-plausible assumptions regarding missing outcome data and were similar whether considering trials in adults versus children, lower versus higher doses, different probiotic species, or higher versus lower risk of bias. Our judgment is that the overall evidence warrants moderate confidence in this large relative risk reduction. We downgraded the overall quality of evidence for CDAD to 'moderate' due to imprecision. There were few events (154) and the calculated optimal information size (n = 8218) was more than the total sample size. With respect to the incidence of C. difficile infection, a secondary outcome, pooled complete case results from 13 trials (961 participants) did not show a statistically significant reduction. The incidence of C. difficile infection was 12.6% in the probiotics group compared to 12.7% in the placebo or no treatment control group (RR 0.89; 95% CI 0.64 to 1.24). Adverse events were assessed in 26 studies (3964 participants) and our pooled complete case analysis indicates probiotics reduce the risk of adverse events by 20% (RR 0.80; 95% CI 0.68 to 0.95). In both treatment and control groups the most common adverse events included abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance. For the short-term use of probiotics in patients that are not immunocompromised or severely debilitated, we consider the strength of this evidence to be moderate.

AUTHORS' CONCLUSIONS

Based on this systematic review and meta-analysis of 23 randomized controlled trials including 4213 patients, moderate quality evidence suggests that probiotics are both safe and effective for preventing Clostridium difficile-associated diarrhea.

Physiological Properties and Salmonella Growth Inhibition of Probiotic Bacillus Strains Isolated from Environmental and Poultry Sources

The objective of the present study was to describe the physiological properties of seven potential probiotic strains of Bacillus spp. Isolates were characterized morphologically, biochemically, and by 16S rRNA sequence analyses for identification. Tolerance to acidic pH, high osmotic concentrations of NaCl, and bile salts were tested. Isolates were also evaluated for their ability to metabolize different carbohydrates sources. The antimicrobial sensitivity profiles were determined. Inhibition of gastrointestinal Salmonella colonization in an avian model was also evaluated. Five strains of Bacillus were tolerant to acidic conditions (pH 2.0) and all strains were tolerant to a high osmotic pressure (NaCl at 6.5%). Moreover, all strains were able to tolerate concentration of 0.037% bile salts after 24 h of incubation. Three strains were able to significantly reduce Salmonella Typhimurium levels in the crop and in the ceca of broiler-type chickens. Among the 12 antibiotics tested for antibiotic resistance, all strains were resistant to bacitracin and susceptible to gentamycin, neomycin, ormethoprim, triple sulfa, and spectinomycin. Bacterial spore formers have been shown to prevent gastrointestinal diseases in animals and humans. The results obtained in this study show important characteristics to be evaluated when selecting Bacillus spp. candidates to be used as probiotics.

Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge

Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects of common antibiotics on cellulolytic bacteria, lactobacilli, and AAD-associated pathogens in the feces of healthy horses. Fifteen horses were assigned to three treatment groups (blocked by age and sex): control (no antibiotics), trimethoprim-sulfadiazine (PO), or ceftiofur (IM). Fecal samples (n=8 per horse) were taken during dietary adaptation (3 weeks), antibiotic challenge (1 week), and withdrawal (1 week). Bacteria were enumerated by serial dilution and viable count. Cellulolytic bacteria decreased by >99% during administration of either antibiotic (P<0.0001) and were still less than controls at the end of the withdrawal period (P<0.0001). Fecal samples from horses challenged with ceftiofur had 75% fewer lactobacilli than those from control horses at the end of the antibiotic challenge period (P<0.05). Antibiotic challenged horses also shed more salmonella than control horses (P<0.05). Antibiotics had no effect on the number of Clostridium perfringens isolates. There was no detectable Clostridium difficile during adaptation or in any control horse. C. difficile increased (P<0.0001) to approximately 10(4)cfu/g when horses were challenged with antibiotics, and were still detectable 1 week after withdrawal. These results indicate that antibiotics can disrupt the normal gastrointestinal microbiota and allow proliferation of Salmonella spp. and C. difficile.

Influence of different probiotic lactic Acid bacteria on microbiota and metabolism of rats with dysbiosis

Lactic acid bacteria (LAB) are often used for prevention and treatment of dysbiosis. However, the action of various strains of LAB on metabolism and digestion under these conditions are poorly understood. The purpose of this study was to investigate the influence of probiotic LAB on metabolism, digestion and microbiota in animals with dysbiosis. After administration of ampicillin and metronidazole male Wistar rats, were fed products containing Enterococcus faecium L3 (E.f.), Lactobacillus fermentum Z (L.f.) or milk (control 1). Animals in control group 2 were fed milk, after water instead of antibiotics. Dyspeptic symptoms disappeared after administration of probiotic compared with control 1. At the end of the experiment, an increase in the content of enterococci and lactobacilli in the proximal part of the small intestine was found in the animals treated with E.f. and L.f., respectively. After the introduction of probiotic enterococci, the quantity of lactobacilli and bifidobacteria in the intestines of rats increased, and the content of Klebsiella spp. and Escherichia coli decreased in comparison with the control group 1 and the group fed lactobacilli. The activity of alkaline phosphatase and aspartate transaminase was greater in blood serum of rats with dysbiosis receiving milk and lactobacilli. Intestinal alkaline phosphatase activity increased in the epithelium and chyme in the jejunum of the animals treated with L. f. and in the chyme only in the animals treated with E. f. Thus, the specific effects of different strains of probiotic LAB on the microbiota, and on metabolism and digestion of various nutrients were demonstrated.

Effects of bilberry (Vaccinium myrtillus) in combination with lactic acid bacteria on intestinal oxidative stress induced by ischemia-reperfusion in mouse

Intestinal ischemia-reperfusion (I/R) results in oxidative stress, inflammation, and tissue injuries. The present study investigates the antioxidative and anti-inflammatory effects of a dietary supplement of bilberry, either alone or in combination with Lactobacillus plantarum RESO56, L. plantarum HEAL19, or Pediococcus acidilactici JAM046, in an I/R-induced model for oxidative stress in mice. A bilberry diet without addition of bacteria significantly decreased both lipid peroxidation (p = 0.001) and mucosal injury in the ileum. Of 14 anthocyanins identified in bilberry, anthocyanin arabinosides were the most resistant to absorption and microbial degradation in the intestines. Cyanidin-3-glucoside and delphinidin-3-glucoside seemed to be mostly absorbed in the stomach and upper part of the small intestine, while malvidin-3-galactoside, peonidin-3-glucoside, peonidin-3-galactoside, and petunidin-3-galactoside seemed to be digested by the microbiota in the cecum. Bilberry strongly influenced the composition of the cecal microbiota. In conclusion, a food supplement of bilberry protected small intestine against oxidative stress and inflammation induced by ischemia-reperfusion.

Empirical Evaluation of Visual Fatigue from Display Alignment Errors Using Cerebral Hemodynamic Responses

The purpose of this study was to investigate the effect of stereoscopic display alignment errors on visual fatigue and prefrontal cortical tissue hemodynamic responses. We collected hemodynamic data and perceptual ratings of visual fatigue while participants performed visual display tasks on 8 ft × 6 ft NEC LT silver screen with NEC LT 245 DLP projectors. There was statistical significant difference between subjective measures of visual fatigue before air traffic control task (BATC) and after air traffic control task (ATC 3), (P < 0.05). Statistical significance was observed between left dorsolateral prefrontal cortex oxygenated hemoglobin (l DLPFC-HbO₂), left dorsolateral prefrontal cortex deoxygenated hemoglobin (l DLPFC-Hbb), and right dorsolateral prefrontal cortex deoxygenated hemoglobin (r DLPFC-Hbb) on stereoscopic alignment errors (P < 0.05). Thus, cortical tissue oxygenation requirement in the left hemisphere indicates that the effect of visual fatigue is more pronounced in the left dorsolateral prefrontal cortex.

Lactobacillus plantarum CCFM8661 alleviates lead toxicity in mice

Lead causes a broad range of adverse effects in humans and animals. The objective was to evaluate the potency of lactobacilli to bind lead in vitro and the protective effects of a selected Lactobacillus plantarum CCFM8661 against lead-induced toxicity in mice. Nine strains of bacteria were used to investigate their binding abilities of lead in vitro, and L. plantarum CCFM8661 was selected for animal experiments because of its excellent lead binding capacity. Both living and dead L. plantarum CCFM8661 were used to treat 90 male Kunming mice during or after the exposure to 1 g/L lead acetate in drinking water. The results showed oral administration of both living and dead L. plantarum CCFM8661 offered a significant protective effect against lead toxicity by recovering blood δ-aminolevulinic acid dehydratase activity, decreasing the lead levels in blood and tissues, and preventing alterations in the levels of glutathione, glutathione peroxidase, malondialdehyde, superoxide dismutase, and reactive oxygen species caused by lead exposure. Moreover, L. plantarum CCFM8661 was more effective when administered consistently during the entire lead exposure, not after the exposure. Our results suggest that L. plantarum CCFM8661 has the potency to provide a dietary strategy against lead toxicity.

The detoxication of nitrate by two antioxidants or a probiotic, and the effects on blood and seminal plasma profiles and reproductive function of New Zealand White rabbit bucks

Forty-two New Zealand White male rabbits were housed individually in wire cages and randomly distributed among six experimental groups of seven rabbits each, during 16 to 61 weeks of age. There were three main nitrate groups: 0 (tap water), 350 and 700 ppm. Within the 700 ppm of nitrate, there were four subgroups, in which one group was used as control group and the other three groups were supplemented with either 200 ppm of ascorbic acid (vitamin (Vit) C), 200 ppm of Vit E with 0.2 ppm of selenium (Se) and 1000 ppm of probiotic. The nitrate was supplemented as a sodium nitrate. The aim is to test the ability of Vit C and Vit E, Se and probiotic on the deleterious effects (blood and seminal plasma biochemical constituents, semen quality and productive performance) of nitrate in drinking water. Rabbits given nitrate at 700 ppm had significantly lower plasma globulin, red blood cells (RBCs), hemoglobin (Hgb), packed cell volume % (PCV%) and total antioxidant capacity (TAC) than those given the other concentrations of nitrate. Vit C, Vit E with Se and probiotic resulted in significantly (P < 0.05) greater Hgb, RBCs, PCV% and TAC than those of bucks given water supplemented with only 700 ppm nitrate, but the aspartate aminotransferase and alanine aminotransferase concentrations in seminal plasma were lower. Testosterone in the blood plasma and the seminal plasma was significantly (P < 0.05) lower in rabbits given 700 ppm nitrate than in those given other concentrations of nitrate. Vit C, Vit E with Se and the probiotic significantly increased testosterone, fertility, number of offspring and total offspring weight of rabbits sired by bucks supplemented with 700 ppm of nitrate.

Performance, egg quality, and immune response of laying hens fed diets supplemented with mannan-oligosaccharide or an essential oil mixture under moderate and hot environmental conditions

In total, 432 thirty-six-week-old laying hens were fed a basal diet supplemented with mannan-oligosaccharide (MOS) or an essential oil mixture (EOM) from 36 to 51 wk of age. Hens were divided into 3 equal groups replicated 6 times with 24 hens per replicate. No significant difference was observed among the dietary treatments in terms of performance indices. Different from the dietary manipulation, high environmental temperatures negatively influenced all of the laying performance traits except the feed conversion ratio in association with the diminished feed consumption. The MOS, and particularly the EOM, tended to alleviate the deleterious effect of heat stress on BW gain. Mortality was higher in MOS-fed hens than with other treatments. A supplementation diet with MOS or EOM provided increments in eggshell weight (P < 0.01). Relative albumen weight was significantly decreased (P < 0.05) in response to EOM or MOS supplementation; however, this was not the case in the yolk weight rate. The MOS decreased albumen height and Haugh unit (P < 0.05). High environmental temperatures hampered entire egg quality characteristics except for the eggshell breaking strength and egg yolk weight. These results indicated that heat stress adversely affected both productive performance and egg quality. As for the results of this study, neither MOS nor EOM was efficacious in improving efficiency of egg production and stimulating humoral immune response in laying hens reared under moderate and hot climatic conditions. However, the ameliorative effect exerted by MOS and EOM on eggshell characteristics is conclusive.

Lactobacillus acidophilus and Lactobacillus reuteri modulate cytokine responses in gnotobiotic pigs infected with human rotavirus

Probiotic lactic acid bacteria (LAB) have been shown to alleviate inflammation, enhance the immunogenicity of rotavirus vaccines, or reduce the severity of rotavirus diarrhoea. Although the mechanisms are not clear, the differential Th1/Th2/Th3-driving capacities and modulating effects on cytokine production of different LAB strains may be the key. Our goal was to delineate the influence of combining two probiotic strains of Lactobacillus acidophilus and Lactobacillus reuteri on the development of cytokine responses in neonatal gnotobiotic pigs infected with human rotavirus (HRV). We demonstrated that HRV alone, or HRV plus LAB, but not LAB alone, initiated serum cytokine responses, as indicated by significantly higher concentrations of IFN-α, IFN-γ, IL-12, and IL-10 at postinoculation day (PID) 2 in the HRV only and LAB+HRV+ pigs compared to LAB only and LAB-HRV- pigs. Peak cytokine responses coincided with the peak of HRV replication. LAB further enhanced the Th1 and Th2 cytokine responses to HRV infection as indicated by significantly higher concentrations of IL-12, IFN-γ, IL-4 and IL-10 in the LAB+HRV+ pigs compared to the LAB-HRV+ pigs. The LAB+HRV+ pigs maintained relatively constant concentrations of TGF-β compared to the HRV only group which had a significant increase at PID 2 and decrease at PID 7, suggesting a regulatory role of LAB in maintaining gut homeostasis. At PID 28, cytokine secreting cell (CSC) responses, measured by ELISpot, showed increased Th1 (IL-12, IFN-γ) CSC numbers in the LAB+HRV+ and LAB-HRV+ groups compared to LAB only and LAB-HRV- pigs, with significantly increased IL-12 CSCs in spleen and PBMCs and IFN-γ CSCs in spleen of the LAB+HRV+ group. Thus, HRV infection alone, but not LAB alone was effective in inducing cytokine responses but LAB significantly enhanced both Th1 and Th2 cytokines in HRV-infected pigs. LAB may also help to maintain immunological homeostasis during HRV infection by regulating TGF-β production.

The obesity and fatty liver are reduced by plant-derived Pediococcus pentosaceus LP28 in high fat diet-induced obese mice

We evaluated the effect of an oral administration of a plant-derived lactic acid bacterium, Pediococcus pentosaceus LP28 (LP28), on metabolic syndrome by using high fat diet-induced obese mice. The obese mice were divided into 2 groups and fed either a high fat or regular diet for 8 weeks. Each group was further divided into 3 groups, which took LP28, another plant-derived Lactobacillus plantarum SN13T (SN13T) or no lactic acid bacteria (LAB). The lean control mice were fed a regular diet without inducing obesity prior to the experiment. LP28 reduced body weight gain and liver lipid contents (triglyceride and cholesterol), in mice fed a high fat diet for 8 weeks (40%, 54%, and 70% less than those of the control group without LAB, and P = 0.018, P<0.001, and P = 0.021, respectively), whereas SN13T and the heat treated LP28 at 121°C for 15 min were ineffective. Abdominal visceral fat in the high fat diet mice fed with LP28 was also lower than that without LAB by 44%, although it was not significant but borderline (P = 0.076). The sizes of the adipocytes and the lipid droplets in the livers were obviously decreased. A real-time PCR analyses showed that lipid metabolism-related genes, such as CD36 (P = 0.013), SCD1 encoding stearoyl-CoA desaturase 1 (not significant but borderline, P = 0.066), and PPARγ encoding peroxisome proliferator-activated receptor gamma (P = 0.039), were down-regulated by taking LP28 continuously, when compared with those of the control group. In conclusion, LP28 may be a useful LAB strain for the prevention and reduction of the metabolic syndrome.

Probiotics prevent the development of 1,2-dimethylhydrazine (DMH)-induced colonic tumorigenesis through suppressed colonic mucosa cellular proliferation and increased stimulation of macrophages

Probiotics modulate immunity and inhibit colon carcinogenesis in experimental models, but these effects largely depend on the bacterial strain, and the precise mechanisms are not well understood. Therefore, we studied the effect of Bifidobacterium longum and/or Lactobacillus gasseri on the development of 1,2-dimethylhydrazine (DMH)-induced colonic precancerous lesions and tumors in mice while delineating the possible mechanisms involved. The results suggest that dietary consumption of probiotics (B. longum and L. gasseri) resulted in a significant inhibition of DMH-induced aberrant crypt foci (ACF) formation in male ICR mice. Long-term (24 weeks) dietary consumption of probiotics resulted in a reduction of colon tumor multiplicity and the size of the tumors. Administration of B. longum and L. gasseri suppressed the rate of colonic mucosa cellular proliferation in a manner correlating with the inhibition of tumor induction by DMH. In addition, the phagocytic activity of peritoneal macrophages was significantly increased in the DMH-treated mice that were fed various doses of B. longum, but not with L. gasseri or combined probiotics (B. longum + L. gasseri). We also found that L. gasseri significantly increased the proliferation of RAW264.7 macrophage cells through an increase in S phase DNA synthesis, which was related to the up-regulation of proliferating cell nuclear antigen (PCNA) and cyclin A. Taken together, these results demonstrate the in vivo chemopreventive efficacy and the immune stimulating mechanisms of dietary probiotics against DMH-induced colonic tumorigenesis.

Probiotic lactic acid bacteria in the gastro-intestinal tract: health benefits, safety and mode of action

Lactic acid bacteria (LAB) have received considerable attention as probiotics over the past few years. This concept has grown from traditional dairy products to a profitable market of probiotic health supplements and functional foods. Extensive research is done on novel potential probiotic strains, with specific emphasis on their health benefits and mode of action. Criteria for the selection of probiotic strains have only recently been formulated by the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO). Several in vitro techniques have been developed to evaluate the probiotic properties of strains. In many cases, this is followed by in vivo tests. Safety studies are also obligatory, as a few cases of bacteremia caused by LAB have been reported. This review focuses on the health benefits and safety of LAB probiotics, the criteria used to select a probiotic, mode of action and the impact these organisms have on natural microbiota in the gastro-intestinal tract.

Probiotics for patients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure and/or portosystemic shunt. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient's quality of life and daily functioning and represent a significant burden on health care resources. Probiotics are live microorganisms, which when administered in adequate amounts may confer a health benefit on the host.

OBJECTIVES

To quantify the beneficial and harmful effects of any probiotic in any dosage, compared with placebo or no intervention, or with any other treatment for patients with any grade of acute or chronic hepatic encephalopathy as assessed from randomised trials.

SEARCH METHODS

We searched the The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, conference proceedings, reference lists of included trials and the WHO international clinical trials registry until April 2011 registry platform to identify new and ongoing trials.

SELECTION CRITERIA

We included randomised trials that compared probiotics in any dosage with placebo or no intervention, or with any other treatment in patients with hepatic encephalopathy.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed the risk of bias of the included trials and extracted data on relevant outcomes, with differences resolved by consensus. We conducted random-effects model meta-analysis due to obvious heterogeneity of patients and interventions. A P value of 0.05 or less was defined as significant. Dichotomous outcomes are expressed as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials of which 550 participants were randomised. Four of the seven trials compared a probiotic with placebo or no treatment in 245 participants, another trial compared a probiotic with lactulose in 40 participants , and the remaining two trials compared a probiotic with both placebo and lactulose in 265 participants. Each trial used different types of probiotics. Duration of administration of the experimental intervention varied from 10 days to 180 days. Two trials were industry funded, and five were unclear about origin of funding. All trials had high risk of bias. When probiotics were compared with no treatment, there was no significant difference in all-cause mortality (2 trials, 105 participants; 1/57 (2%) versus 1/48 (2%): RR 0.72; 95% CI 0.08 to 6.60), lack of recovery (4 trials, 206 participants; 54/107 (50%) versus 68/99 (69%): RR 0.72; 95% CI 0.49 to 1.05), adverse events (3 trials, 145 participants; 2/77 (3%) versus 6/68 (9%): RR 0.34; 95% CI 0.08 to 1.42), quality of life (1 trial, 20 participants contributed to the physical quality of life measurement, 20 participants contributed to the mental quality of life: MD Physical 0.00; 95% CI -5.47 to 5.47; MD Mental 4.00; 95% CI -1.82 to 9.82), or change of/or withdrawal from treatment (3 trials, 175 participants; 11/92 (12%) versus 7/83 (8%): RR 1.28; 95% CI 0.52 to 3.19). No trial reported sepsis or duration of hospital stay as an outcome. Plasma ammonia concentration was significantly lower for participants treated with probiotic at one month (3 trials, 226 participants: MD -2.99 μmol/L; 95% CI -5.70 to -0.29) but not at two months (3 trials, 181 participants: MD -1.82 μmol/L; 95% CI -14.04 to 10.41). Plasma ammonia decreased the most in the participants treated with probiotic at three months (1 trial, 73 participants: MD -6.79 μmol/L; 95% CI -10.39 to -3.19). When probiotics were compared with lactulose no trial reported all-cause mortality, quality of life, duration of hospital stay, or septicaemia. There were no significant differences in lack of recovery (3 trials, 173 participants; 47/87 (54%) versus 44/86 (51%): RR 1.05; 95% CI 0.75 to 1.47), adverse events (2 trials, 111 participants; 3/56 (5%) versus 6/55 (11%): RR 0.57; 95% CI 0.06 to 5.74), change of/or withdrawal from treatment at one month (3 trials, 190 participants; 8/95 (8%) versus 7/95 (7%): RR 1.10; 95% CI 0.40 to 3.03), plasma ammonia concentration (2 trials, 93 participants: MD -6.61 μmol/L; 95% CI -30.05 to 16.84), or change in plasma ammonia concentration (1 trial, 77 participants: MD 1.16 μmol/L; 95% CI -1.96 to 4.28).

AUTHORS' CONCLUSIONS

The trials we located suffered from a high risk of systematic errors ('bias') and high risk of random errors ('play of chance'). While probiotics appear to reduce plasma ammonia concentration when compared with placebo or no intervention, we are unable to conclude that probiotics are efficacious in altering clinically relevant outcomes. Demonstration of unequivocal efficacy is needed before probiotics can be endorsed as effective therapy for hepatic encephalopathy. Further randomised clinical trials are needed.

Effects of Bifidobacterium infantis 35624 on post-inflammatory visceral hypersensitivity in the rat

BACKGROUND

Irritable bowel syndrome patients have abnormal visceral perception. Probiotic organisms may produce beneficial effects in these patients by reducing visceral hypersensitivity.

AIM

To investigate the effects of the probiotic organism, Bifidobacterium infantis 35624, on post-inflammatory visceral hypersensitivity in rats.

METHODS

Colitis was induced using intracolonic administration of trinitrobenzenesulfonic acid; control rats received saline (day 0). Myeloperoxidase (MPO) levels and colonic damage scores were determined. From days 15-29, rats (n = 10/group) rats were orally dosed with 2 ml of B. infantis ≥ 10(8) colony-forming units/ml or vehicle (MRS broth). A second series of rats (n = 10/group) was dosed in the same manner from days 15-59. The level of colonic stimulation during colorectal distension (CRD) was determined by recording a visceromotor response (VMR) to CRD at 30 mmHg pre- and post-treatment. Post-treatment samples of colonic tissue were weighed, graded for morphologic damage, and assayed for MPO levels.

RESULTS

All rats were hypersensitive at day 15. On day 30, hypersensitivity to colorectal distension remained in the vehicle group, but was significantly reduced in the B. infantis group (mean VMR/10 min: vehicle = 15.4 ± 1.0 vs. B. infantis = 7.6 ± 1.0, p < 0.001). A similar, significant effect was observed at day 60. On both day 30 and day 60, tissue weight, colonic damage scores, and MPO levels resembled those of control animals.

CONCLUSIONS

Oral administration of Bifidobacterium infantis 35624 normalized sensitivity to colorectal distension in a rat model of post-inflammatory colonic hypersensitivity.

Effect of herbal extract granules combined with probiotic mixture on irritable bowel syndrome with diarrhea: study protocol for a randomized controlled trial

Background

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by abdominal pain and change of bowel habits without organic disease. Many patients seek alternative IBS treatments because of the limitations of conventional treatments. Gwakhyangjeonggisan (GJS), a herbal formula, has long been used for alleviating diarrhea-predominant IBS (D-IBS) in traditional medicine. Duolac7S, which comprises 7 bacterial species as probiotics, has been frequently used for D-IBS. Although GJS and Duolac7S have been administered simultaneously in many D-IBS patients, no study has investigated the effects of GJS and Duolac7S combination therapy on D-IBS.

Methods/Design

The current trial is a randomized, double-blinded, placebo-controlled, 4-arm study. After a 2-week run-in period, 60 patients with D-IBS will be randomly assigned to one of the 4 combination groups consisting of GJS (water extract granules, 3 g/pack, 3 times a day) with Duolac7S (powder form, 1 capsule, 2 times a day) or their placebos and followed up for 2 weeks. The assigned treatments will last for 8 weeks. The primary outcomes are adequate relief of IBS pain and discomfort and the proportion of responders (on a weekly basis). The secondary outcomes are visual analog scale for IBS symptoms (on a daily basis), quality of life (at 0, 8, and 10 weeks), intestinal permeability, and composition of intestinal microbiota (at 0 and 8 weeks).

Discussion

The present study is designed to examine the safety and efficacy of GJS and Duolac7S combination therapy on D-IBS. Our study provides the clinical evidence of a new therapeutic strategy for D-IBS.

Trial registration

ClinicalTrials.gov NCT01342718 .

Oxidative stress response in the opportunistic oral pathogen Fusobacterium nucleatum

The anaerobic, Gram-negative bacillus Fusobacterium nucleatum plays a vital role in oral biofilm formation and the development of periodontal disease. The organism plays a central bridging role between early and late colonizers within dental plaque and plays a protective role against reactive oxygen species. Using a two-dimensional gel electrophoresis and mass spectrometry approach, we have annotated 78 proteins within the proteome of F. nucleatum subsp. nucleatum and identified those proteins whose apparent intracellular concentrations change in response to either O(2)- or H(2)O(2)-induced oxidative stress. Three major protein systems were altered in response to oxidative stress: (i) proteins of the alkyl hydroperoxide reductase/thioredoxin reductase system were increased in intracellular concentration; (ii) glycolytic enzymes were modified by oxidation (i.e. D-glyceraldehyde 3-phosphate dehydrogenase, and fructose 6-phosphate aldolase) or increased in intracellular concentration, with an accompanying decrease in ATP production; and (iii) the intracellular concentrations of molecular chaperone proteins and related proteins (i.e. ClpB, DnaK, HtpG, and HrcA) were increased.

In vitro fermentation of linear and alpha-1,2-branched dextrans by the human fecal microbiota

The role of structure and molecular weight in fermentation selectivity in linear α-1,6 dextrans and dextrans with α-1,2 branching was investigated. Fermentation by gut bacteria was determined in anaerobic, pH-controlled fecal batch cultures after 36 h. Inulin (1%, wt/vol), which is a known prebiotic, was used as a control. Samples were obtained at 0, 10, 24, and 36 h of fermentation for bacterial enumeration by fluorescent in situ hybridization and short-chain fatty acid analyses. The gas production of the substrate fermentation was investigated in non-pH-controlled, fecal batch culture tubes after 36 h. Linear and branched 1-kDa dextrans produced significant increases in Bifidobacterium populations. The degree of α-1,2 branching did not influence the Bifidobacterium populations; however, α-1,2 branching increased the dietary fiber content, implying a decrease in digestibility. Other measured bacteria were unaffected by the test substrates except for the Bacteroides-Prevotella group, the growth levels of which were increased on inulin and 6- and 70-kDa dextrans, and the Faecalibacterium prausnitzii group, the growth levels of which were decreased on inulin and 1-kDa dextrans. A considerable increase in short-chain fatty acid concentration was measured following the fermentation of all dextrans and inulin. Gas production rates were similar among all dextrans tested but were significantly slower than that for inulin. The linear 1-kDa dextran produced lower total gas and shorter time to attain maximal gas production compared to those of the 70-kDa dextran (branched) and inulin. These findings indicate that dextrans induce a selective effect on the gut flora, short-chain fatty acids, and gas production depending on their length.

Probiotics for photoprotection

Specific strains of probiotic, have been identified as beneficial to influence the composition and/or metabolic activity of the endogenous microbiota and some of these strains have been also shown to inhibit the growth of a wide range of enteropathogens. The first aim of using probiotics has been to improve the composition of the intestinal microbiota from a potentially harmful composition towards a composition that would be beneficial to the host.Beyond their capacity to influence positively the composition of the intestinal microbiota, several lines of evidence suggest that some probiotic bacteria can modulate the immune system both at the local and systemic levels thereby improving immune defense mechanisms and/or downregulate immune disorders such as allergies or intestinal inflammation.Skin reflects the general health status and aging. Different human trials widely suggest that probiotic supplementation might be useful in the management of atopic dermatitis. Based on these properties it appears that, beyond the gut, probiotics might exert their benefits at the skin level.In a randomized double blind placebo-controlled clinical trial, we investigated whether the probiotic bacteria Lactobacillus johnsonii NCC 533 (La1) could modulate the cutaneous immune homeostasis altered by solar-simulated UV exposure in humans. After, UV exposure to twice 1.5 MED, we demonstrated that La1 intake facilitated an earlier recovery of Epidermal cells allostimulatory function. Thus, this clinical data strengthen the assumption that certain probiotics can contribute to modulate skin immune system leading to the preservation of the skin homeostasis. Altogether the data affords the possibility of designing new strategies based on a nutritional approach for the prevention of UV-induced damaging effects.

The gut microbiota and human health with an emphasis on the use of microencapsulated bacterial cells

The gut microbiota plays a crucial role in maintaining health. Alterations of the gut bacterial population have been associated with a number of diseases. Past and recent studies suggest that one can positively modify the contents of the gut microbiota by introducing prebiotics, probiotics, synbiotics, and other therapeutics. This paper focuses on probiotic modulation of the gut microbiota by their delivery to the lower gastrointestinal tract (GIT). There are numerous obstacles to overcome before microorganisms can be utilized as therapeutics. One important limitation is the delivery of viable cells to the lower GIT without a significant loss of cell viability and metabolic features through the harsh conditions of the upper GIT. Microencapsulation has been shown to overcome this, with various types of microcapsules available for resolving this limitation. This paper discusses the gut microbiota and its role in disease, with a focus on microencapsulated probiotics and their potentials and limitations.

Effect of probiotic bacterial strains of Lactobacillus, Bifidobacterium, and Enterococcus on enteroaggregative Escherichia coli

The effects of nine probiotic strains of Lactobacillus, Bifidobacterium, and Enterococcus on the growth, adhesion activity, and biofilm formation of enteroaggregative Escherichia coli (EAggEC) were examined. The culture supernatant of the E. faecium strain, with or without pH adjustment to a neutral pH, had a strong bactericidal effect on EAggEC, including induction of membrane damage and cell lysis. Supernatants of the L. casei ss. casei and L. casei ss. rhamnosus strains also had a bactericidal effect on EAggEC, but this activity was abolished by pH adjustment to a neutral pH. No inhibitory effect of the culture supernatants of Bifidobacterium or E. faecalis strains was detected. Adhesion of EAggEC to intestinal epithelial cells was not inhibited by the bacterial strains tested. Two strains of L. casei enhanced EAggEC biofilm formation, which was characterized by increased bacterial proliferation. These results suggest that the three different bacterial species; Lactobacillus, Bifidobacterium, and Enterococcus, have different effects on EAggEC, and that further analysis is required for the practical use of these bacteria as probiotics against EAggEC infection.

Dietary proteins as determinants of metabolic and physiologic functions of the gastrointestinal tract

Dietary proteins elicit a wide range of nutritional and biological functions. Beyond their nutritional role as the source of amino acids for protein synthesis, they are instrumental in the regulation of food intake, glucose and lipid metabolism, blood pressure, bone metabolism and immune function. The interaction of dietary proteins and their products of digestion with the regulatory functions of the gastrointestinal (GI) tract plays a dominant role in determining the physiological properties of proteins. The site of interaction is widespread, from the oral cavity to the colon. The characteristics of proteins that influence their interaction with the GI tract in a source-dependent manner include their physico-chemical properties, their amino acid composition and sequence, their bioactive peptides, their digestion kinetics and also the non-protein bioactive components conjugated with them. Within the GI tract, these products affect several regulatory functions by interacting with receptors releasing hormones, affecting stomach emptying and GI transport and absorption, transmitting neural signals to the brain, and modifying the microflora. This review discusses the interaction of dietary proteins during digestion and absorption with the physiological and metabolic functions of the GI tract, and illustrates the importance of this interaction in the regulation of amino acid, glucose, lipid metabolism, and food intake.

In vitro and in vivo effects of Enterococcus faecalis CECT7121 on Toxocara canis

The aim of the present paper was to evaluate the larvicidal effect of Enterococcus faecalis CECT7121 (Ef7121) on the Toxocara canis cycle both in vitro and in vivo. For the in vitro experiments, T. canis larvae were incubated with the supernatants of Ef7121 (EI) and mutant Ef7121 (EIm), in a pre-culture of Ef7121 (EII) and in a fresh culture with Ef7121 (EIII) and the Ef7121 mutant strain (EIIIm). The viability of the larvae was calculated after a 48 h incubation. A significant reduction of the viability of T. canis larvae was observed in EI, EII and EIII. A decrease of this inhibitory effect was observed in EIm and EIIIm (p = 0.008). In the in vivo experiments, mice were orally inoculated with three doses of Ef7121. To study the probiotic persistence in the intestine, the animals were sacrificed every four days and their intestines were dissected. The initial average bacterial levels were 9.7 x 10(4) for Ef7121 (colony forming units/g). At the end of the assay the levels were 1.46 x 10(4). No bacterial translocation was detected in mesenteric lymphatic nodules and spleen. Ef7121 interference with the biological cycle was evaluated in mice challenged with T. canis. The interference was significant when the mice were challenged with probiotic and T. canis simultaneously (p = 0.001), but it was not significant when the challenge was performed 15 days after administration of the bacterial inoculum (p = 0.06). In conclusion, Ef7121 possessed in vitro and in vivo larvicidal activity.

Bifidobacterium longum lysate, a new ingredient for reactive skin

Reactive skin is characterized by marked sensitivity to physical (heat, cold, wind) or chemical (topically applied products) stimuli and by the impairment of the skin barrier's ability to repair itself. Several lines of evidence suggest that beyond their capacity to positively influence the composition of intestinal microbiota, some probiotic bacteria can modulate the immune system both at local and systemic levels, thereby improving immune defense mechanisms and/or down-regulating immune disorders such as allergies and intestinal inflammation. Several recent human clinical trials clearly suggest that probiotic supplementation might be beneficial to the skin. Using a probiotic lysate, Bifidobacterium longum sp. extract (BL), we demonstrated first in vitro, and then in a clinical trial, that this non-replicating bacteria form applied to the skin was able to improve sensitive skin. The effect of BL were evaluated first on two different models. Using ex vivo human skin explant model we found a statistically significant improvement versus placebo in various parameters associated with inflammation such as a decrease in vasodilation, oedema, mast cell degranulation and TNF-alpha release. Moreover, using nerve cell cultures in vitro, we showed that after 6 h of incubation in culture medium (0.3-1%), the probiotic lysate significantly inhibited capsaicin-induced CGRP release by neurones. Then, a topical cream containing the active extract was tested in a randomized, double-blind, placebo-controlled trial. Sixty-six female volunteers with reactive skin were randomly given either the cream with the bacterial extract at 10% (n = 33) or the control cream (n = 33). The volunteers applied the cream to the face, arms and legs twice a day for two months. Skin sensitivity was assessed by stinging test (lactic acid) and skin barrier recovery was evaluated by measuring trans-epidermal water loss following barrier disruption induced by repeated tape-stripping at D1, D29 and D57. The results demonstrated that the volunteers who applied the cream with bacterial extract had a significant decrease in skin sensitivity at the end of the treatment. Moreover, the treatment led to increase skin resistance against physical and chemical aggression compared to the group of volunteers who applied the control cream. Notably, the number of strippings required to disrupt skin barrier function was significantly increased for volunteers treated with the active cream. Clinical and self-assessment scores revealed a significant decrease in skin dryness after 29 days for volunteers treated with the cream containing the 10% bacterial extract. Since in vitro studies demonstrated that, on one hand, isolate sensitive neurones release less CGRP under capsaicin stimulation in the presence of the bacterial extract and, on the other hand, increased skin resistance in volunteers applying the test cream, we speculate that this new ingredient may decrease skin sensitivity by reducing neurone reactivity and neurone accessibility. The results of this studies demonstrate that this specific bacterial extract has a beneficial effect on reactive skin. These findings suggest that new approaches, based on a bacteria lysate, could be developed for the treatment and/or prevention of symptoms related to reactive skin.