Prebiotic Substances Research Articles

Colonic fermentation of polyphenolics from Sea buckthorn (Hippophae rhamnoides) berries: Assessment of effects on microbial diversity by Principal Component Analysis

The present study investigates the stability of polyphenolic in Sea buckthorn berries juice (SBJ) during different phases of digestion and its effect on colonic microbial diversity. At each stage, the Total polyphenolic content (TPC), Total antioxidant activity (TAA) and polyphenolic profile was determined. A 1.64 and 2.20 folds increase in TPC with 4.88 and 9.61 folds increase in TAA were observed during gastric and small intestine digestion (p<0.05) with the release of quercetin from food matrix. The digestion resulted in deformation of intact crystalline structure as indicated by scanning electron micrographs. The colonic fermentation resulted in an increase in quercetin, caffeic acid with decrease in rutin and chlorogenic acid after 36h of fermentation (p<0.05). The Shannon diversity index (H) of beneficial groups including Lactic acid bacteria (LAB), Bacteroides/Prevotella and Bifidobacteria was increased by 35%, 71% and 17%, respectively (p<0.05). The PCA analysis indicated that the presence and digestion of polyphenolics promote the proliferation of Bacteroides/Prevotella group as well as Lactic acid bacteria and Bifidobacteria. The results suggest that SBJ is good source of prebiotic substrate in terms of the proliferation of beneficial gut microbiota.

Effect of prebiotic substances on growth, fatty acid profile and probiotic characteristics of Lactobacillus brevis NM101-1

Utilization of both probiotics and prebiotics in diet supplements and food products has gained a great interest because of their health benefits. In the present study, the effect of 6 commercially available prebiotic substances on the growth, acidifying activity, fatty acid profile and probiotic characteristics of Lactobacillus brevis NM101-1 was investigated in vitro for the development of synbiotic preparations. The results indicated the selective fermentability of prebiotics by the probiotic bacterial strain and absence of metabolism by pathogenic bacteria. Garlic and onion extracts as well as chicory flour as sources of inulin were the best carbon sources for growth and acidifying activity of the strain. The addition of onion extract to the medium exerted a significant influence on acetic acid production. However, the highest biosynthesis of lactic acid was recorded in the presence of glucose. Supplementation of MRS medium with prebiotic substances caused an increase in the ratio of unsaturated to saturated fatty acids of bacterial cells. Furthermore, resistance to gastrointestinal conditions, hydrophobicity and inhibition of bacterial pathogens as international guidelines for probiotics were enhanced by a combination of probiotic L. brevis and prebiotics which indicated that a convenient prebiotic substance have to be chosen for each probiotic bacterial strain for potential synbiotic preparation.

Selection of prebiotic oligosaccharides suitable for synbiotic use in calves

The aims of this experiment were to identify suitable commercial prebiotic substrates for bifidobacteria of calf origin and to verify in vivo the effects of the selected prebiotics on survival of applied and naturally occurring bifidobacteria in calf intestines. First, in vitro utilization of selected fructooligosaccharides, galactooligosaccharides, and inulin by Bifidobacterium animalis ssp. animalis (two strains), B. choerinum, B. thermophilum, and B. longum ssp. suis was investigated. The highest specific growth rates were observed with Vivinal® (galactooligosaccharides) and Raftilose P85 (fructooligosaccharides); therefore, these prebiotics were used for in vivo tests. Three groups of calves were investigated. A single dose of a probiotic mixture of five strains of rifampicin-resistant variants of bifidobacteria (RRBs) in form of fermented milk was fed to 2-days-old calves in the first experimental group (PROB). In the second group (SYNB), a single dose of probiotics was administered to calves at the same age, but a prebiotic mixture containing selected substrates was fed to the calves every day until 7 weeks of age (the end of the study). The third group, which did not receive any treatment, was used as a control. The survival of applied and naturally-occurring bifidobacteria and the numbers of selected faecal bacterial groups were determined by cultivation. Our results showed that the fed RRBs were able to survive passage through the gastrointestinal tract, with counts of more than 107 CFU/g in the PROB group. Significantly higher numbers of RRBs (more than 108 CFU/g) were found in the SYNB group at age 4days. RRBs persisted in intestines for at least 49days in both experimental groups without further significant differences. Counts of other determined bacteria were not significantly affected by the treatments. Our results showed that the selected prebiotics improve the survival of bifidobacteria passing through the digestive tract. Selected combination of pro- and prebiotics seems to be promising synbiotic in term of promoting survival of administered bacteria in intestine. However its effect on animal performance must be verified in other experiment with larger groups of animals.

INULIN AS A PREBIOTIC AND FAT REPLACER IN MEAT PRODUCTS

Fat reduction in meat products is demanded by consumers concerning health issues but represents a serious challenge for meat industry as fatty tissue plays an important role for the products properties. Because of that, a special attention is paid to the substances that could replace fatty tissue in meat products. Inulin represents a non digestible fructooligosaccharide that on the one hand represents a good prebiotic substance and from the other hand posses such technological propeties that make it a good fat replacer. In aqueous systems inulin forms a gel having a structure similar to fats, it has neutral taste and smell and have no impact on the aroma of meat products. Inulin could be added to meat products in form of powder as well as a water suspension. Low fat fermented sausages with good sensory quality could be produced with the addition of inulin as a fat replacer, and such products have a bit lower pH- and aw-value and contain a higher number of lactic acid bacteria then conventional products. In heat treated sausages, inulin improves water holding capacity and stability of the low fat meat batter, which reduces cooking loss and shows no adverse effect on the sensory properties of the low fat product. But, there are also certain limitations because it should be paid attention to the degree of polymerization as well as the amount of inulin added the product. Otherwise, on the one hand there could be some adverse effects on sensory properties of the product and from the other hand an excessive amount of inulin could lead to digestive problems by consumers.

In vitro fermentation of different fructo-oligosaccharides by Bifidobacterium strains for the selection of synbiotic combinations

The use of selected probiotics, prebiotics and/or synbiotics, constitute an interesting dietary strategy for intestinal microbiota modulation in case of dysbiosis. Species of the genus Bifidobacterium are among the most currently used probiotics for human consumption since they have shown beneficial effects in the prevention and treatment of some disorders. Bifidobacteria are saccharolytic microorganisms, but their ability to use different carbohydrates varies among strains. In this study, we investigate the utilization of three prebiotic substrates (two different short-chain fructo-oligosaccharides [scFOS] and inulin) by strains of Bifidobacterium, in order to determine the synbiotic potential of the different probiotic/prebiotic combinations. Batch culture fermentations from six Bifidobacterium strains (Bifidobacterium longum IPLA20021, B. longum IPLA20022, Bifidobacterium animalis IPLA20031, B. animalis IPLA20032, B. animalis IPLA20020 and B. animalis Bb12) were carried out in the presence of inulin or scFOS (Synergy or Actilight), or glucose, as carbon source. Bifidobacteria levels were quantified by plate counting. The pH and production of organic acids in the different batch-culture fermentations were also determined. Our results showed that all the studied strains of B. animalis and B. longum were able to utilize scFOS but not inulin. The use of scFOS as carbon source affected the pattern of metabolite's production, when compared with cultures carried out in glucose, particularly in the case of B. longum. The results indicated that the scFOS are well suited to be used in combination with B. animalis or B. longum strains for the development of synbiotic foods or food supplements.

The Microbial Diversity and Its Dynamics in the Ethnic Fermented Foods of the Black Sea Region

Homemade fermented food is a valuable source of biologically active prebiotic substances and probiotic microorganisms. Five prioritized ethnic fermented foods from the Black Sea region: Bosa (Bulgaria), Socata (Romania), Kvass (Russia), fermented beans (Turkey) and Sauerkraut (Ukraine), based on the original recipes using unique microbial starters were studied. The dynamics of microbial compositions during the fermentation process of each product was clarifed and the best combination of lactobacilli starters needed to reproduce the original formulations were defned. In addition to our earlier published data these results demonstrate the opportunity to design novel food products which might be used in the practical implementation of personalized diets.

The Physicochemical Optimization and Acceptability of a Cashew Nut-Based Beverage Varying in Mango Juice and Sugar: A Pilot Study

The development of a lactose-free beverage comes as a new feeding alternative to a product with excellent nutritional and functional characteristics to individuals with food restrictions related to milk. Thus, this study aimed to develop a cashew nut beverage with added mango juice and prebiotic substances by means of evaluating its sensory characteristics and physicochemical optimization. A 22 central composite rotatable design with five repetitions at the central point was applied to evaluate the effect of sugar and juice contents on the analyzed parameters. Data were evaluated by means of the response surface methodology, analysis of variance, and the means comparison test. Formulations with greater combined concentrations of juice and sugar obtained satisfactory acceptance. The means comparison test showed that the formulation that allows for the beverage’s greatest acceptance must contain 40% mango juice and 8% sugar. Soluble solids content was influenced only by the addition of sugar, where the formulations that presented greater solids concentration were the ones which obtained greater sensory acceptance. The beverage’s acidity was influenced only by the juice content, which, besides making formulations significantly more acid, did not affect their acceptance.

Role of theganSPQABOperon in Degradation of Galactan by Bacillus subtilis

Bacillus subtilis possesses different enzymes for the utilization of plant cell wall polysaccharides. This includes a gene cluster containing galactan degradation genes (ganA and ganB), two transporter component genes (ganQ and ganP), and the sugar-binding lipoprotein-encoding gene ganS (previously known as cycB). These genes form an operon that is regulated by GanR. The degradation of galactan by B. subtilis begins with the activity of extracellular GanB. GanB is an endo-β-1,4-galactanase and is a member of glycoside hydrolase (GH) family 53. This enzyme was active on high-molecular-weight arabinose-free galactan and mainly produced galactotetraose as well as galactotriose and galactobiose. These galacto-oligosaccharides may enter the cell via the GanQP transmembrane proteins of the galactan ABC transporter. The specificity of the galactan ABC transporter depends on the sugar-binding lipoprotein, GanS. Purified GanS was shown to bind galactotetraose and galactotriose using thermal shift assay. The energy for this transport is provided by MsmX, an ATP-binding protein. The transported galacto-oligosaccharides are further degraded by GanA. GanA is a β-galactosidase that belongs to GH family 42. The GanA enzyme was able to hydrolyze short-chain β-1,4-galacto-oligosaccharides as well as synthetic β-galactopyranosides into galactose. Thermal shift assay as well as electrophoretic mobility shift assay demonstrated that galactobiose is the inducer of the galactan operon regulated by GanR. DNase I footprinting revealed that the GanR protein binds to an operator overlapping the -35 box of the σ(A)-type promoter of Pgan, which is located upstream of ganS IMPORTANCE: Bacillus subtilis is a Gram-positive soil bacterium that utilizes different types of carbohydrates, such as pectin, as carbon sources. So far, most of the pectin degradation systems and enzymes have been thoroughly studied in B. subtilis Nevertheless, the B. subtilis utilization system of galactan, which is found as the side chain of the rhamnogalacturonan type I complex in pectin, has remained partially studied. Here, we investigated the galactan utilization system consisting of the ganSPQAB operon and its regulator ganR This study improves our knowledge of the carbohydrate degradation systems of B. subtilis, especially the pectin degradation systems. Moreover, the galactan-degrading enzymes may be exploited for the production of galacto-oligosaccharides, which are used as prebiotic substances in the food industry.

Physicochemical and Sensory Properties of Ice Cream Mix Using Different Whole Mill Grains

The aim of the present study was to produce healthy ice cream mixes by replacement of stabilizer with whole mill grains and study their effect on the physicochemical and sensory properties. Total solid (%) was increased with added the powder of grains in all mixes. Protein ranged between3.6 to 4.9 and increased by adding whole grain meal and oats mixes contained the highest protein value. Ash % increased with added milled whole grains Oats mixes contain the highest value of ash. Fat % ranged from 20.66 to 25.90 and oats mixes contained the highest fat %. Total carbohydrate increased with adding the milled whole grains and white corn mixes contained the highest carbohydrate values. Oat mixes gave the highest overrun values. Use of 0.5% milled grain gave the highest melting rate. Increasing apparent viscosity as a result of changing kind of whole mill grains and concentration of adding: (oats; sorghum; white corn; yellow corn) and control samples. Viscosity of ice cream mixes contained1% milled grain was the highest between mixes and were the best in organoleptic properties Thus we recommend to use the milled whole grain in ice cream mixes especially oats to give the consumer a new nutraceutical product with prebiotic substances e.g β glucans , vitamins …etc. .

Selection of potential probiotic bifidobacteria and prebiotics for elderly by using in vitro faecal batch cultures

The gut microbiota plays an important role in host health. The ageing process affects this microbial community, and therefore, the use of functional foods to restore the microbiota of elderly constitutes an interesting strategy. To this end, probiotics and prebiotics targeted at correcting the specific microbiota alterations occurring during senescence are needed. We performed an in vitro selection of bifidobacterial strains and prebiotic substrates on the basis of their ability to counterbalance the specific microbiota aberrancies previously identified in the elderly population. Batch cultures of faeces from elderly were carried out adding different strains of Bifidobacterium or prebiotics. The effects of these strains/prebiotics upon gut microbiota were assessed by quantitative PCR and the concentrations of short chain fatty acids determined by gas chromatography-FID/MS. The target-specific selection process applied in this study allowed the preliminary selection of two Bifidobacterium strains and a prebiotic fructooligosaccharide on the basis of their specific properties for the modulation of the microbiota of elders. Overall, this study identifies potentially probiotic strains and prebiotic substrates for the development of functional foods specifically targeted to the senior population.

Microbiological characterization and functionality of set-type yogurt fermented with potential prebiotic substrates Cudrania tricuspidata and Morus alba L. leaf extracts

The objective of this study was to investigate the effect of 2 plant leaf extracts on fermentation mechanisms and health-promoting activities and their potential as a nutraceutical prebiotics ingredient for application in dairy products. The individual active phenolic compounds in the plant extract-supplemented milk and yogurts were also identified. Compared with control fermentation, the plant extracts significantly increased the growth and acidification rate of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. In particular, plant extract components, including monosaccharides, formic acid, and hydroxycinnamic acid, such as neo-chlorogenic, chlorogenic, and caffeic acid, together play a stimulatory role and cause this beneficial effect on the growth of yogurt culture bacteria through fermentation. In addition, supplementation with the plant extracts enhanced antioxidant activities with increased total phenolic contents, especially the highest antioxidant activity was observed in yogurt supplemented with Cudrania tricuspidata leaf extract.

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Poultry industry has undergone rapid growth during last three decades. For which even higher usage of antibiotics, both as growth promoters as well as therapeutic agents, has been adopted. However, due to the fear of resistance development in bacterial populations to antibiotics, presence of antibiotic residues in poultry products and increasing consumer demand for products free from antibiotic residues, search for alternatives that could replace antibiotics without causing loss to productivity or product quality has accelerated. Such alternatives in poultry include the use of organic acids, probiotic microorganisms, prebiotic substrates that benefit proliferation of beneficial bacterial populations or synbiotic (combinations of prebiotics and probiotics) ensuring better production and maintaining health of the birds. Others include vitamins and minerals, herbal drugs, plant extracts, phytobiotics and antimicrobial peptides. Probiotic organisms provides competition to pathogenic organisms for intestinal colonizing sites, reduce the diversion of nutrients for harmful microbes and the toxins produced by them and stimulates the immune systems. Similarly, prebiotic offers an alternative, as it alters the intestinal microbes and immune system to reduce colonization by pathogens and allows proliferation of beneficial microflora in the gut. Even using synbiotic is a better strategy for enhancing poultry production, however, more research is needed for selection of probiotic, prebiotics or synbiotics either alone or in combination that can result in the selection of strains capable of performing effectively in the gastrointestinal tract. The contents of this review will be useful for researchers to enrich their knowledge on alternatives of antibiotics in poultry birds without compromising performance of birds and bird welfare. Ajit Singh Yadav 1, *, Gautham Kolluri 1 , Marappan Gopi 1 , Kumaragurubaran Karthik 2 , Yashpal Singh Malik 2 and Kuldeep Dhama 2

Effect of Bifidobacterium upon Clostridium difficile Growth and Toxicity When Co-cultured in Different Prebiotic Substrates.

The intestinal overgrowth of Clostridium difficile, often after disturbance of the gut microbiota by antibiotic treatment, leads to C. difficile infection (CDI) which manifestation ranges from mild diarrhea to life-threatening conditions. The increasing CDI incidence, not only in compromised subjects but also in traditionally considered low-risk populations, together with the frequent relapses of the disease, has attracted the interest for prevention/therapeutic options. Among these, probiotics, prebiotics, or synbiotics constitute a promising approach. In this study we determined the potential of selected Bifidobacterium strains for the inhibition of C. difficile growth and toxicity in different carbon sources. We conducted co-cultures of the toxigenic strain C. difficile LMG21717 with four Bifidobacterium strains (Bifidobacterium longum IPLA20022, Bifidobacterium breve IPLA20006, Bifidobacterium bifidum IPLA20015, and Bifidobacterium animalis subsp. lactis Bb12) in the presence of various prebiotic substrates (Inulin, Synergy, and Actilight) or glucose, and compared the results with those obtained for the corresponding mono-cultures. C. difficile and bifidobacteria levels were quantified by qPCR; the pH and the production of short chain fatty acids was also determined. Moreover, supernatants of the cultures were collected to evaluate their toxicity using a recently developed model. Results showed that co-culture with B. longum IPLA20022 and B. breve IPLA20006 in the presence of short-chain fructooligosaccharides, but not of Inulin, as carbon source significantly reduced the growth of the pathogen. With the sole exception of B. animalis Bb12, whose growth was enhanced, the presence of C. difficile did not show major effects upon the growth of the bifidobacteria. In accordance with the growth data, B. longum and B. breve were the strains showing higher reduction in the toxicity of the co-culture supernatants.

Oligosaccharides Released from Milk Glycoproteins Are Selective Growth Substrates for Infant-Associated Bifidobacteria

Milk, in addition to nourishing the neonate, provides a range of complex glycans whose construction ensures a specific enrichment of key members of the gut microbiota in the nursing infant, a consortium known as the milk-oriented microbiome. Milk glycoproteins are thought to function similarly, as specific growth substrates for bifidobacteria common to the breast-fed infant gut. Recently, a cell wall-associated endo-β-N-acetylglucosaminidase (EndoBI-1) found in various infant-borne bifidobacteria was shown to remove a range of intact N-linked glycans. We hypothesized that these released oligosaccharide structures can serve as a sole source for the selective growth of bifidobacteria. We demonstrated that EndoBI-1 released N-glycans from concentrated bovine colostrum at the pilot scale. EndoBI-1-released N-glycans supported the rapid growth of Bifidobacterium longum subsp. infantis (B. infantis), a species that grows well on human milk oligosaccharides, but did not support growth of Bifidobacterium animalis subsp. lactis (B. lactis), a species which does not. Conversely, B. infantis ATCC 15697 did not grow on the deglycosylated milk protein fraction, clearly demonstrating that the glycan portion of milk glycoproteins provided the key substrate for growth. Mass spectrometry-based profiling revealed that B. infantis consumed 73% of neutral and 92% of sialylated N-glycans, while B. lactis degraded only 11% of neutral and virtually no (<1%) sialylated N-glycans. These results provide mechanistic support that N-linked glycoproteins from milk serve as selective substrates for the enrichment of infant-associated bifidobacteria capable of carrying out the initial deglycosylation. Moreover, released N-glycans were better growth substrates than the intact milk glycoproteins, suggesting that EndoBI-1 cleavage is a key initial step in consumption of glycoproteins. Finally, the variety of N-glycans released from bovine milk glycoproteins suggests that they may serve as novel prebiotic substrates with selective properties similar to those of human milk oligosaccharides. It has been previously shown that glycoproteins serve as growth substrates for bifidobacteria. However, which part of a glycoprotein (glycans or polypeptides) is responsible for this function was not known. In this study, we used a novel enzyme to cleave conjugated N-glycans from milk glycoproteins and tested their consumption by various bifidobacteria. The results showed that the glycans selectively stimulated the growth of B. infantis, which is a key infant gut microbe. The selectivity of consumption of individual N-glycans was determined using advanced mass spectrometry (nano-liquid chromatography chip-quadrupole time of flight mass spectrometry [nano-LC-Chip-Q-TOF MS]) to reveal that B. infantis can consume the range of glycan structures released from whey protein concentrate.

Steering Endogenous Butyrate Production in the Intestinal Tract of Broilers as a Tool to Improve Gut Health.

The ban on antimicrobial growth promoters and efforts to reduce therapeutic antibiotic usage has led to major problems of gastrointestinal dysbiosis in livestock production in Europe. Control of dysbiosis without the use of antibiotics requires a thorough understanding of the interaction between the microbiota and the host mucosa. The gut microbiota of the healthy chicken is highly diverse, producing various metabolic end products, including gases and fermentation acids. The distal gut knows an abundance of bacteria from within the Firmicutes Clostridium clusters IV and XIVa that produce butyric acid, which is one of the metabolites that are sensed by the host as a signal. The host responds by strengthening the epithelial barrier, reducing inflammation, and increasing the production of mucins and antimicrobial peptides. Stimulating the colonization and growth of butyrate-producing bacteria thus may help optimizing gut health. Various strategies are available to stimulate butyrate production in the distal gut. These include delivery of prebiotic substrates that are broken down by bacteria into smaller molecules which are then used by butyrate producers, a concept called cross-feeding. Xylo-oligosaccharides (XOS) are such compounds as they can be converted to lactate, which is further metabolized to butyrate. Probiotic lactic acid producers can be supplied to support the cross-feeding reactions. Direct feeding of butyrate-producing Clostridium cluster IV and XIVa strains are a future tool provided that large scale production of strictly anaerobic bacteria can be optimized. Current results of strategies that promote butyrate production in the gut are promising. Nevertheless, our current understanding of the intestinal ecosystem is still insufficient, and further research efforts are needed to fully exploit the capacity of these strategies.

In vitro fermentation of prebiotic carbohydrates by intestinal microbiota in the presence of Lactobacillus amylovorus DSM 16998.

The aim of this study was to evaluate the assimilation of the prebiotics fructooligosaccharides (FOS), galactooligosaccharides (GOS), and Konjac glucomannan oligosaccharides (KGMO) by three human (H1, H2 and H3) and pig (P1, P2 and P3) faecal microbiotas in the presence of the potentially probiotic strain Lactobacillus amylovorus DSM 16698, using an in vitro batch fermentation model. Total bacteria and L. amylovorus populations were quantified using qPCR and biochemical features (pH, production of short chain fatty acids (SCFA), lactate, ammonia, and carbohydrate assimilation) were determined. L. amylovorus did not have a competitive advantage under in vitro conditions, reflected by its reduced relative abundance during fermentation despite the carbohydrate sources added. Pig microbiota sustained more stable probiotic counts. Intermittently produced lactate was possibly assimilated by the microbiota and converted to other SCFA as the carbohydrates were assimilated, with H3 probably having a methanogenic metabolism with high lactate and acetate consumption except in the presence of FOS, which assimilation resulted in the highest total SCFA for this volunteer. Addition of FOS also resulted in lower pH and ammonia, which might have been used as nitrogen source by pig microbiota. KGMO needed longer fermentation periods to be completely assimilated by both human and porcine faecal microbiotas. Overall, our results reinforce the notion that care must be taken when generalising the effects claimed for a given probiotic or potentially probiotic strain, including the combination with different prebiotic substrates, since they may vary considerably among individuals, which is important when studying potentially pro- and prebiotic combinations for application as functional foods and feed ingredients.

Association of Lactobacillus crispatus with fructo-oligosaccharides and ascorbic acid in hydroxypropyl methylcellulose vaginal insert

The aim of this work was to develop a synbiotic vaginal insert containing the probiotic strain Lactobacillus crispatus BC5, the prebiotic substrate fructo-oligosaccharide and the antioxidant agent ascorbic acid, for the prophylaxis and therapy of vaginal infections. Mucoadhesive in situ gelling vaginal inserts based on hydroxypropyl methylcellulose were prepared by freeze-drying, stored at +2–8°C for 90 days and characterized in terms of technological and functional properties. Complete survival of L. crispatus BC5 was found immediately after insert preparation (96.08%) as well as after 90 days of storage (95.82%) in the vaginal inserts containing fructo-oligosaccharide, ascorbic acid and skimmed milk. Synbiotic inserts showed improved mucoadhesion ability (from three- to five-fold) with respect to a standard formulation based on hydroxypropyl methylcellulose alone. Moreover, inserts allowed to modulate lactobacilli release in virtue of the different amounts of fructo-oligosaccharide. Finally, antimicrobial activity was exerted by L. crispatus BC5 released from the vaginal formulation.

Raffinose family oligosaccharides in seed of Glycine max cv. Chiang Mai60 and potential source of prebiotic substances

SummaryRaffinose family oligosaccharides (RFOs) content in Glycine max seed of cultivar Chiang Mai60, a local soybean of Thailand, was investigated. RFOs and other low molecular weight sugars were extracted by 50% (v/v) ethanol and quantified by high‐performance liquid chromatography (HPLC). The prebiotic property of this extract was subsequently studied by in vitro method. The results showed that the concentrations of raffinose, stachyose and verbascose were 6.74 ± 1.62, 145.32 ± 18.74 and 1.60 ± 0.52 mg g−1 dry seed, respectively, while glucose and sucrose were detected at 10.73 ± 1.35 and 13.28 ± 2.16 mg g−1 dry seed, respectively. The growth of four Lactobacilli probiotics were increased significantly in a basal liquid medium supplemented with this ethanolic extract as carbon source compared to glucose supplementation. Subsequently, defined mixed culture was studied and it was found that growth stimulation of total Lactobacilli by extracted sugars resulted in the suppression of Escherichia coli and Salmonella enterica serovar Typhimurium growth. It could be concluded that this cultivar showed the RFOs‐rich content and a potential to be a source of an effective prebiotic substance for food application.

Characteristics of Metroxylon sagu resistant starch type III as prebiotic substance.

Resistant starch type III (RS3 ) was produced from sago (Metroxylon sagu) and evaluated for its characteristics as a prebiotic. Two RS3 samples designated sago RS and HCl-sago RS contained 35.71% and 68.30% RS, respectively, were subjected to hydrolyses by gastric juice and digestive enzymes and to absorption. Both sago RS and HCl-sago RS were resistant to 180 min hydrolysis by gastric acidity at pH 1 to 4 with less than 0.85% hydrolyzed. Both samples were also resistant toward hydrolysis by gastrointestinal tract enzymes and intestinal absorption with 96.75% and 98.69% of RS3 were recovered respectively after 3.5 h digestion and overnight dialysis at 37 °C. Sago RS3 supported the growth of both beneficial (lactobacilli and Bifidobacteria) and pathogenic microbes (Escherichia coli, Campylobacter coli, and Clostridium perfringens) in the range of 2.60 to 3.91 log10 CFU/mL. Hence, prebiotic activity score was applied to describe the extent to which sago RS3 supports selective growth of the lactobacilli and bifidobacteria strains over pathogenic bacteria. The highest scores were obtained from Bifidobacterium sp. FTDC8943 grown on sago RS (+0.26) and HCl-sago RS (+0.24) followed by L. bulgaricus FTDC1511 grown on sago RS (+0.21). The findings had suggested that sago RS3 has the prebiotic partial characteristics and it is suggested to further assess the suitability of sago RS3 as a prebiotic material.

Exopolysaccharides Produced by Lactic Acid Bacteria and Bifidobacteria as Fermentable Substrates by the Intestinal Microbiota

The functional food market, including products formulated to maintain a “healthy” gut microbiota, i.e. probiotics and prebiotics, has increased enormously since the end of the last century. In order to favor the competitiveness of this sector, as well as to increase our knowledge of the mechanisms of action upon human health, new probiotic strains and prebiotic substrates are being studied. This review discusses the use of exopolysaccharides (EPS), both homopolysaccharides (HoPS) and heteropolysaccharides (HePS), synthesized by lactic acid bacteria and bifidobacteria as potential prebiotics. These extracellular carbohydrate polymers synthesized by some gut inhabitants seem to be resistant to gastrointestinal digestion; these are susceptible as well to biodegradability by the intestinal microbiota depending on both the physicochemical characteristics of EPS and the pool of glycolytic enzymes harbored by microbiota. Therefore, although the chemical composition of these HoPS and HePS is different, both can be fermentable substrates by intestinal inhabitants and good candidates as prebiotic substrates. However, there are limitations for their use as additives in the food industry due to, on the one hand, their low production yield and, on the other hand, a lack of clinical studies demonstrating the functionality of these biopolymers.