Synbiotic Combination Research Articles

Bacterial metabolism and health-related effects of galacto-oligosaccharides and other prebiotics

Most studies involving prebiotic oligosaccharides have been carried out using inulin and its fructo-oligosaccharide (FOS) derivatives, together with various forms of galacto-oligosaccharides (GOS). Although many intestinal bacteria are able to grow on these carbohydrates, most investigations have demonstrated that the growth of bifidobacteria, and to a lesser degree lactobacilli, is particularly favoured. Because of their safety, stability, organoleptic properties, resistance to digestion in the upper bowel and fermentability in the colon, as well as their abilities to promote the growth of beneficial bacteria in the gut, these prebiotics are being increasingly incorporated into the Western diet. Inulin-derived oligosaccharides and GOS are mildly laxative, but can result in flatulence and osmotic diarrhoea if taken in large amounts. However, their effects on large bowel habit are relatively minor. Although the literature dealing with the health significance of prebiotics is not as extensive as that concerning probiotics, considerable evidence has accrued showing that consumption of GOS and FOS can have significant health benefits, particularly in relation to their putative anti-cancer properties, influence on mineral absorption, lipid metabolism, and anti-inflammatory and other immune effects such as atopic disease. In many instances, prebiotics seem to be more effective when used as part of a synbiotic combination.

Selection and optimization procedure of synbiotic for cholesterol removal

A selection and optimization procedure for the synbiotic combination of probiotic and prebiotics was established to optimize its cholesterol removal in vitro. In light of fermentability, prebiotics utilization by probiotics was highly variable and interspecies differences existed. Based on the results of fermentability, L. plantarum LS12, Ls31, LP529 and L. ruminis La3 could be the better candidates for symbiotic research. The bile tolerance of all the tested strains could be improved by the strain-specific prebiotics comparing to the control carbon source (glucose). The strain LS12 was finally selected to form the symbiotic according to its better ability to ferment prebiotics and bile tolerance, while the five prebiotics (FOS, stachyose, GOS, IMO and mannitol) were selected to make their synbiotic combination because of their better enhancement of bile tolerance and growth support to LS12. The synbiotic combination for cholesterol removal was optimized by use of response surface methodology. The first-order model showed that the selected prebiotics mannitol and GOS were significant factors. Then through the second-order polynomial regression model, the optimum conditions of the two factors for cholesterol removal by the synbiotic were suggested.

Randomized clinical trial of effect of synbiotics, neomycin and mechanical bowel preparation on intestinal barrier function in patients undergoing colectomy

The aim of this study was to investigate whether it is possible to modulate gut microflora and preserve intestinal barrier function during elective colorectal surgery by using combinations of oral antibiotics, synbiotics and mechanical bowel preparation (MBP). Ninety-two patients were randomly assigned to one of four groups. Group 1 had MBP only, group 2 had neomycin + MBP, group 3 had synbiotics + neomycin + MBP, and group 4 had synbiotics + neomycin but no MBP. Changes in gut microflora were assessed by culturing nasogastric aspirates and polymerase chain reaction-denaturing gradient gel electrophoresis of faecal samples. Intestinal barrier function was determined by microbiological confirmation of bacterial translocation and measurement of intestinal permeability. The inflammatory response was monitored by measurement of serum C-reactive protein and interleukin 6, and septic morbidity was recorded prospectively. Four patients were excluded owing to protocol violation, leaving 24 patients in group 1, 22 in group 2, 20 in group 3 and 22 in group 4 for analysis. There was a significant decrease in Enterobacteriaceae in group 3 compared with the other groups. Group 3 had a significantly lower incidence of translocation after bowel mobilization (P < 0.001). There was no significant difference between the groups in intestinal permeability, inflammatory response or septic morbidity. The combination of MBP, neomycin and synbiotics reduces the prevalence of faecal Enterobacteriaceae and bacterial translocation; however, this was not associated with a reduction in inflammatory response or septic morbidity in this study. Larger trials are needed before a change in practice can be recommended.

Prebiotic and Synbiotic Fructooligosaccharide Administration Fails to Reduce the Severity of Experimental Colitis in Rats

Opposing effects of the prebiotic, fructooligosaccharide, have been reported in experimental colitis. We compared the effects of the prebiotic, fructooligosaccharide, alone and in synbiotic combination with Lactobacillus fermentum BR11, on the development of dextran sulfate sodium-induced colitis in rats. Rats consumed an 18 percent casein-based diet or diet supplemented with 6 percent fructooligosaccharide or maltodextrin for 14 days. The synbiotic group was gavaged 1 ml of L. fermentum BR11 (1x10(9) cfu/ml) twice daily. From Days 7 to 14, colitis was induced via 3 percent dextran sulfate sodium in drinking water. Disease activity was assessed daily, and at killing, gastrointestinal organs were measured, weighed, and examined by quantitative histology, proliferating cell nuclear antigen immunohistochemistry, and colonic myeloperoxidase activity. Administration of dextran sulfate sodium resulted in an increased colitic disease activity, and an increased colon and cecum weight compared with normal controls. Colon and cecum weights were further increased in dextran sulfate sodium+fructooligosaccharide (colon: 19 percent; cecum: 48 percent) and dextran sulfate sodium+fructooligosaccharide/L. fermentum BR11-treated rats (16 and 62 percent) compared with dextran sulfate sodium+vehicle-treatment. Dextran sulfate sodium+fructooligosaccharide-treated rats displayed an 81 percent increase in colonic myeloperoxidase activity compared with dextran sulfate sodium-treated controls. Histologic damage severity scores increased in dextran sulfate sodium+vehicle, dextran sulfate sodium+fructooligosaccharide, and dextran sulfate sodium+fructooligosaccharide/L. fermentum BR11-treated rats compared with normal controls (P<0.05). Crypt depth increased in all treatments compared with normal controls (P<0.01). No protection from dextran sulfate sodium-colitis was accorded by fructooligosaccharide alone or in synbiotic combination with L. fermentum BR11, whereas fructooligosaccharide actually increased some indicators of colonic injury.

Effect of dietary intervention with different pre- and probiotics on intestinal bacterial enzyme activities

To investigate the influence of different pre- and probiotics on faecal beta-glucuronidase and beta-glucosidase activity, as one of the claimed beneficial effects of pre- and probiotics is the hypothesis that these substrates are able to reduce the production of toxic and carcinogenic metabolites by suppressing specific enzyme activities in the colon. Department of Gastrointestinal Research, University Hospital Gasthuisberg, KU Leuven, Belgium. The effect was evaluated in a randomized, crossover study in 53 healthy volunteers who were randomly assigned to one of five treatment groups. At the start and after a 4-week treatment period, the healthy volunteers collected faeces during 72 h. Lactulose and oligofructose-enriched inulin (OF-IN) were chosen as prebiotics, whereas Lactobacillus casei Shirota, Bifidobacterium breve and Saccharomyces boulardii were selected as probiotics. Two synbiotic combinations were evaluated as well. The enzyme activity was assessed spectrophotometricly. Lactulose and OF-IN significantly decreased beta-glucuronidase activity, whereas a tendency to a decreased beta-glucuronidase activity was observed after L. casei Shirota and B. breve intake. To the contrary, B. breve increased beta-glucosidase levels. Supplementation with the synbiotic did not appear to be more beneficial than either compound alone. No influence of S. boulardii was noted. Administration of lactulose, OF-IN, L. casei Shirota or B. breve resulted in a decrease of the beta-glucuronidase activity, which is considered beneficial for the host.

Bifidobacterium infantisstrains with and without a combination of Oligofructose and Inulin (OFI) attenuate inflammation in DSS-induced colitis in rats

BackgroundPathogenesis of inflammatory bowel disease is thought to be through different factors and there is a relationship between the gut flora and the risk of its development. Probiotics can manipulate the microflora in chronic inflammation and may be effective in treating inflammation. Bifidobacterium are saccharolytic and their growth in the gut can be promoted by non-absorbable carbohydrates and its increase in the colon appears to be of benefit.MethodsOligofructose and inulin (OFI) alone and the two B. infantis DSM 15158 and DSM 15159 with and without OFI, were fed to Sprague-Dawley rats for 7 days prior to colitis induction and administrations continued for another 7 days with the DSS. Colitis severity assessed using a Disease Activity Index. Samples were collected 7 days after colitis induction, for intestinal bacterial flora, bacterial translocation, short chain fatty acids (SCFAs), myeloperoxidase (MPO), cytokines (IL-1β, TNF-α, IL-10 and TGF-β) and malondialdehyde (MDA).ResultsOFI alone or the B. infantis strains with and without OFI improved significantly the DAI and decreased colonic MPO activity. Colonic tissue IL-1β decreased significantly in all treated groups except B. infantis DSM 15158. MDA decreased significantly in B. infantis DSM 15159 with and without OFI compared to colitis control. Succinic acid increased significantly in OFI group with and without DSM 15159 compared to all groups. Sum values of propionic, succinic acid and butyric acid increased significantly in all groups compare to the colitis control. Bacterial translocation to mesenteric lymph nodes decreased significantly in all groups compared to colitis control. Translocation to the liver decreased significantly in all groups compare to the colitis control and OFI + B. infantis DSM 15158 groups.ConclusionAdministrations of OFI and Bifidobacterium improve DSS-induced acute colitis and have an anti-inflammatory effect. Major differences in effect were observed between the two B. infantis strains as indicated in MDA and succinic acid concentration as well as bacterial translocation rate in synbiotic combinations.

Molecular Monitoring of the Fecal Microbiota of Healthy Human Subjects during Administration of Lactulose and Saccharomyces boulardii

Diet is a major factor in maintaining a healthy human gastrointestinal tract, and this has triggered the development of functional foods containing a probiotic and/or prebiotic component intended to improve the host's health via modulation of the intestinal microbiota. In this study, a long-term placebo-controlled crossover feeding study in which each subject received several treatments was performed to monitor the effect of a prebiotic substrate (i.e., lactulose), a probiotic organism (i.e., Saccharomyces boulardii), and their synbiotic combination on the fecal microbiota of three groups of 10 healthy human subjects differing in prebiotic dose and/or intake of placebo versus synbiotic. For this purpose, denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA gene amplicons was used to detect possible changes in the overall bacterial composition using the universal V(3) primer and to detect possible changes at the subpopulation level using group-specific primers targeting the Bacteroides fragilis subgroup, the genus Bifidobacterium, the Clostridium lituseburense group (cluster XI), and the Clostridium coccoides-Eubacterium rectale group (cluster XIVa). Although these populations remained fairly stable based on DGGE profiling, one pronounced change was observed in the universal fingerprint profiles after lactulose ingestion. Band position analysis and band sequencing revealed that a band appearing or intensifying following lactulose administration could be assigned to the species Bifidobacterium adolescentis. Subsequent analysis with real-time PCR (RT-PCR) indicated a statistically significant increase (P < 0.05) in total bifidobacteria in one of the three subject groups after lactulose administration, whereas a similar but nonsignificant trend was observed in the other two groups. Combined RT-PCR results from two subject groups indicated a borderline significant increase (P = 0.074) of B. adolescentis following lactulose intake. The probiotic yeast S. boulardii did not display any detectable universal changes in the DGGE profiles, nor did it influence the bifidobacterial levels. This study highlighted the capacity of an integrated approach consisting of DGGE analysis and RT-PCR to monitor and quantify pronounced changes in the fecal microbiota of healthy subjects upon functional food administration.

A Synbiotic Combination of Resistant Starch and Bifidobacterium lactis Facilitates Apoptotic Deletion of Carcinogen-Damaged Cells in Rat Colon

Recent reports suggest that combinations of prebiotics and probiotics may be protective against colorectal cancer. We examined in rats the effects of probiotic bacteria, resistant starch (RS), and their interaction on luminal and epithelial events of relevance to the development of colorectal cancer. Lyophilized cultures (1 x 10(10) cfu/g) of Lactobacillus acidophilus and/or Bifidobacterium lactis were added at a concentration of 1% by weight to a semipurified diet containing either low-RS (no supplemented RS) or moderate-RS (10% Hi-maize) and fed to male Sprague-Dawley rats for 4 wk. Experimental end-points included cecal bacterial enumeration, fecal and cecal pH, SCFA levels, cell proliferation, and the acute apoptotic response to a genotoxic carcinogen (AARGC; measured 6 h after a single azoxymethane injection). A significant interaction between dietary RS and supplemental bacteria was observed for the AARGC in the colon and fecal pH (P < 0.01). Rats fed the moderate-RS diet in combination with B. lactis had a significantly greater AARGC in the colon than those fed that diet without B. lactis. Fecal pH was elevated in the moderate-RS fed rats supplemented with bacteria. The moderate-RS diet increased cell proliferation and crypt column height (P < 0.001) compared with the low-RS diet. SCFA levels and numbers of bifidobacteria and lactobacilli species were also increased (P < 0.001) by the moderate-RS diet, whereas pH levels and total coliforms were lowered (P < 0.001). The synbiotic combination of RS and B. lactis significantly facilitated the apoptotic response to a genotoxic carcinogen in the distal colon of rats. It appears likely that ingested RS acts as a metabolic substrate, thus creating the right conditions for B. lactis to exert its proapoptotic action. Because the synbiotic combination of these agents facilitates the apoptotic response to DNA damage by a cancer initiator in the colon of rats, it warrants further study for its capacity to protect against colorectal cancer.

The SYNCAN project: goals, set-up, first results and settings of the human intervention study

Experimental evidence on the anticancer properties of dietary prebiotics such as chicory inulin and oligofructose and dietary probiotics has accumulated in recent years. Various experimental models ranging from chemoprevention studies, tumour implantation models to genetically modified mice models, etc. have systematically shown the protective effects of these food ingredients. In some studies it appeared that synbiotics (combination of pre- and probiotics) exerted synergistic activity against processes of carcinogenesis. The logical next step in research was to find out if these observations also would be valid for human volunteers. This was the principal goal of the EU-sponsored SYNCAN project (QLK1-1999-346) which involved the integration of an in vitro study to select the most suitable synbiotic preparation, the application of this synbiotic in an in vivo rat model of chemically induced colon cancer, and, as the heart of the project, the investigation of the synbiotic effects in a human intervention study. The in vitro tests consisted of fermentation studies where the interaction of pre- and probiotics was studied. Cell-free supernatants were generated from various synbiotic combinations fermented by faecal slurry, which were then used to optimise a series of bioassays. In the rat study the anticarcinogenic effect of prebiotics and synbiotics but not of probiotics was demonstrated. Using tissue samples generated in this model, attempts were made to gain a better insight into the mechanisms underlying cancer development. The human intervention study consisted of two groups of volunteers. One group was composed of people at high risk (polypectomised subjects) for colon cancer and the other of volunteers (colon cancer subjects) who had previously undergone 'curative resection' for colon cancer but were not currently receiving treatment. The present paper describes the experimental design of the SYNCAN study, and demonstrates a functional effect of the synbiotic preparation (probiotic survival during gastrointestinal transit and modification of the intestinal flora). Detailed experimental outcome of the human intervention study will be reported elsewhere.

Probiotic Research in Australia, New Zealand and the Asia-Pacific Region

Although the epicentres of probiotic research in the past decade have been Japan and Europe, researchers in the Asia-Pacific region have actively contributed to the growing understanding of the intestinal microbial ecosystem, and interactions between gut bacteria, diet and health of the human host. A number of new probiotic strains have been developed in the region that have been demonstrated to have beneficial impacts on health in animal and human trials, including improved protection against intestinal pathogens and modulation of the immune system. Probiotics targeted to animals, including aquaculture, feature heavily in many Asian countries. Developments in probiotic technologies have included microencapsulation techniques, antimicrobial production in fermented meats, and synbiotic combinations. In particular, the impact of resistant starch on the intestinal environment and fermentation by intestinal bacteria has been intensively studied and new probiotic strains selected specifically for synbiotic combinations with resistant starch. This paper provides an overview of probiotic research within Australia, New Zealand and a number of Asian countries, and lists scientists in the Asia-Pacific region involved in various aspects of probiotic research and development.

Fecal Water Genotoxicity Is Predictive of Tumor-Preventive Activities by Inulin-Like Oligofructoses, Probiotics (Lactobacillus rhamnosus and Bifidobacterium lactis), and Their Synbiotic Combination

: The measurement of fecal water genotoxicity in human colon cells could be a useful biomarker to study effects of diet in the colon. Here we assessed aqueous fecal extracts of samples from a chronic study with rats fed prebiotics, probiotics, and their combination. Treatments were maltodextrins (controls), inulin/oligofructoses (prebiotic), Lactobacillus rhamnosus, and Bifidobacterium lactis (probiotics) or both (synbiotic). Azoxymethane (AOM) was administered to initiate tumors. Rat feces were collected at 0 and 10 days and 2, 4, and 8 mo, and cecal contents were collected at 8 mo. Aqueous phases were prepared and tested for genotoxicity in HT29 colon cells using the comet assay. The studied types of intervention reduced fecal and cecal genotoxicity. DNA damage by samples from AOM-treated, tumor-free rats was significantly lower than from tumor-bearing animals, especially after 4 mo of synbiotic and prebiotic interventions. Inulin-based diets reduced exposure to genotoxins in the feces, directly reflecting the reported reduction of tumor incidence in these animals. Evidence is provided for the validity of this measurement as a biomarker of chemoprevention because 1) fecal water genotoxicity reflected genotoxic exposure in the cecum, 2) tumor incidence and fecal genotoxicity were directly related, and 3) these interventions reduced tumor risks by reducing exposure to genotoxins in the gut.

Application of prebiotics and probiotics in poultry production

The intestinal microbiota, epithelium, and immune system provide resistance to enteric pathogens. Recent data suggest that resistance is not solely due to the sum of the components, but that cross-talk between these components is also involved in modulating this resistance. Inhibition of pathogens by the intestinal microbiota has been called bacterial antagonism, bacterial interference, barrier effect, colonization resistance, and competitive exclusion. Mechanisms by which the indigenous intestinal bacteria inhibit pathogens include competition for colonization sites, competition for nutrients, production of toxic compounds, or stimulation of the immune system. These mechanisms are not mutually exclusive, and inhibition may comprise one, several, or all of these mechanisms. Consumption of fermented foods has been associated with improved health, and lactic acid bacteria (lactobacilli and bifidobacteria) have been implicated as the causative agents for this improved health. Research over the last century has shown that lactic acid bacteria and certain other microorganisms can increase resistance to disease and that lactic acid bacteria can be enriched in the intestinal tract by feeding specific carbohydrates. Increased bacterial resistance to antibiotics in humans has caused an increase in public and governmental interest in eliminating sub-therapeutic use of antibiotics in livestock. An alternative approach to sub-therapeutic antibiotics in livestock is the use of probiotic microorganisms, prebiotic substrates that enrich certain bacterial populations, or synbiotic combinations of prebiotics and probiotics. Research is focused on identifying beneficial bacterial strains and substrates along with the conditions under which they are effective.

In vitro fermentation of cereal dietary fibre carbohydrates by probiotic and intestinal bacteria

AbstractA range of probiotic and other intestinal bacteria were examined for their ability to ferment the dietary fibre carbohydrates β‐glucan, xylan, xylo‐oligosaccharides (XOS) and arabinoxylan. β‐Glucan was fermented by Bacteroides spp and Clostridium beijerinckii but was not fermented by lactobacilli, bifidobacteria, enterococci or Escherichia coli. Unsubstituted xylan was not fermented by any of the probiotic bacteria examined. However, many Bifidobacterium species and Lactobacillus brevis were able to grow to high yields using XOS. XOS were also efficiently fermented by some Bacteroides isolates but not by E coli, enterococci, Clostridium difficile, Clostridium perfringens or by the majority of intestinal Lactobacillus species examined. Bifidobacterium longum strains were able to grow well using arabinoxylan as the sole carbon source. These organisms hydrolysed and fermented the arabinosyl residues from arabinoxylan but did not substantially utilise the xylan backbone of the polysaccharide. Arabinoxylan was not fermented by lactobacilli, enterococci, E coli, C perfringens or C difficile and has potential to be an applicable carbohydrate to complement probiotic Bif longum strains in synbiotic combinations.© 2002 Society of Chemical Industry

The Effect of Synbiotics on Colon Carcinogenesis in Rats

Evidence indicates that consumption of probiotic microorganisms such as bifidobacteria reduces the risk of colon cancer in animal models. Feeding certain fructans such as oligofructose and inulin, which are thought to selectively increase the growth of intestinal bifidobacteria (i.e., a prebiotic effect), also has been shown to reduce colon cancer risk. The objective of our study was twofold, i.e., to determine whether the combination of bifidobacteria and oligofructose would have an additive effect (i.e., synbiotic) in reducing colon cancer risk in rats, and to determine whether other oligosaccharides would also be effective as part of a synbiotic combination. The development of colonic preneoplastic lesions (aberrant crypts) was used as an index of colon cancer risk. In one series of experiments, rats were given the carcinogen 1,2-dimethylhydrazine (DMH) and administered one of the following treatments: skim milk (control), bifidobacteria (bifido), oligofructose (OF) or bifido + OF. Neither bifido nor OF alone significantly reduced aberrant crypt number. Bifido + OF reduced aberrant crypt number in five of six experiments, although the reduction was significant in only one. However, a paired comparison of the six experiments indicated a significant overall reduction in aberrant crypts by bifido + OF (P = 0.039). Soybean oligosaccharide (SBO) and wheat bran oligosaccharide (WBO) were also fed in combination with bifidobacteria. In two other experiments, SBO did not alter the number of aberrant crypts compared with the control, whereas WBO reduced aberrant crypt number in one experiment but not in another. Of OF, SBO and WBO, only SBO reduced the colonic mucosa proliferation compared with the control. These results suggest that the combination of bifidobacteria and oligofructose reduces colon cancer risk in carcinogen-treated rats, but the effect of other oligosaccharides is uncertain.