Health benefit application of functional oligosaccharides

Effect of prebiotic konjac mannanoligosaccharide on growth performances, intestinal microflora, and digestive enzyme activities in yellow catfish, Pelteobagrus fulvidraco

In the present study, konjac mannanoligosaccharide (KMOS) was evaluated as a prebiotic in yellow catfish. The fish were fed with diets containing KMOS in four concentrations: 0 g kg(-1) (C), 1.0 g kg(-1) (KM1), 2.0 g kg(-1) (KM2), and 3.0 g kg(-1) (KM3) for 49 days, respectively. Another group fed with diets containing 3.0 g kg(-1) yeast cell wall mannanoligosaccharide (MOS) (M3) was set as positive control. The results indicated that fish receiving the diets supplemented with KMOS or MOS showed higher relative gain rate (RGR), specific growth rate (SGR), and lower feed conversion ratio (FCR) with significantly differences (P < 0.05) than those fed with the basal diets. Moreover, fish receiving the diets with 2.0 g kg(-1) KMOS inclusion showed higher RGR, SGR, and lower FCR (P < 0.05) than that feeding the diets supplemented with 3.0 g kg(-1) MOS. The quantities of Bifidobacterium spp. were significantly increased (P < 0.05). Meanwhile, Escherichia coli and Aeromonas spp. were significantly reduced (P < 0.05) in the fish-feeding diets with 2.0 g kg(-1) KMOS supplement. Compared with the control group, the significantly enhancement of protease and amylase activity (P < 0.05) in intestine and pancreas was observed in fish fed with diets containing KMOS or MOS. Collectively, an optimum level of KMOS inclusion in diets could modulate intestinal microflora, induce digestive enzyme activity, and improve the growth performance of yellow catfish significantly.

Stachyose-enriched α-galacto-oligosaccharides regulate gut microbiota and relieve constipation in mice

This study probed the effects of Deshipu stachyose granules (DSG), a novel oligosaccharide preparation (55.3% stachyose, 25.8% raffinose, and 9.7% verbascose), on gut microbiota and constipation in mice. Mice were administered intragastrically without or with DSG (0.42, 0.83, and 2.49 g/kg bw), and feces were collected after 14 days of treatment and subjected to classical microbiological assays. Selective index (SI) and prebiotic index (PI) were incorporated to evaluate the prebiotic effect. DSG at 0.83 g/kg bw scored the highest SI and PI scores, thus supporting a strong prebiotic role. In addition, the impact of DSG (0.42, 0.83, and 1.68 g/kg bw) on defecation function of constipated mice was determined. Ink propulsion rate in the small intestine was significantly improved by DSG treatment. DSG supplementation also distinctly increased the weight and number of black feces within 5 h and evidently shortened the defecating time of first black feces, as compared with the constipation control mice. All of these findings indicate that DSG may promote the growth of beneficial intestinal bacteria and inhibit pathogenic bacteria and also facilitate intestinal peristalsis and fecal excretion, thereby enhancing intestinal health and relieving constipation.

Screening the ability of natural feed ingredients to interfere with the adherence of enterotoxigenicEscherichia coli(ETEC) K88 to the porcine intestinal mucus

The inhibition of the attachment of bacteria to the intestine by receptor analogues could be a novel approach to prevent enterotoxigenicEscherichia coli(ETEC) K88-induced diarrhoea in piglets. The objective of the present study was to screen the ability of different feed ingredients (FI) to bind to ETEC K88 (adhesion test, AT) and to block its attachment to the porcine intestinal mucus (blocking test, BT) usingin vitromicrotitration-based models. In the AT, wheat bran (WB), casein glycomacropeptide (CGMP) and exopolysaccharides exhibited the highest adhesion to ETEC K88 (P< 0·001). In the BT, WB, CGMP and locust bean (LB) reduced the number of ETEC K88 attached to the intestinal mucus (P< 0·001). For WB and LB, fractionation based on their carbohydrate components was subsequently carried out, and each fraction was evaluated individually. None of the WB fractions reduced the adhesion of ETEC K88 to the mucus as did the original extract, suggesting that a protein or glycoprotein could be involved in the recognition process. With regard to the LB fractions, the water-extractable material reduced the adhesion of ETEC K88 (P< 0·001) to the mucus similar to the original extract (P< 0·001), indicating, in this case, that galactomannans or phenolic compounds could be responsible for the recognition process. In conclusion, among the FI screened, the soluble extracts obtained from WB, LB and CGMP exhibited the highest anti-adhesive properties against ETEC K88 in the BT. These results suggest that they may be good candidates to be included in diets of weaned piglets for the prevention of ETEC K88-induced diarrhoea.

Inhibitory effects of resistant starch (RS3) as a carrier for stachyose on dextran sulfate sodium-induced ulcerative colitis in C57BL/6 mice

The aim of this study was to determine the effects of resistant starch 3 (RS3) as a carrier for stachyose on dextran sulfate sodium (DSS)-induced colitis in C57BL/6 mice. RS3 microspheres carrying stachyose (RS3 + stachyose) were produced and evaluated as a potentially improved colitis therapy for this study. The body weights of the mice treated with RS3 + stachyose were higher compared with those of DSS-treated control mice. RS3 + stachyose reduced the levels of the serum pro-inflammatory cytokines IL-6 and TNF-α to a greater extent compared with the same concentration of stachyose combined with ordinary starch (stachyose + starch). Histopathological examination of sections of colon tissues showed that the RS3 + stachyose group recovered well from colitis; however, the tissue sections of the stachyose + starch group presented necrosis to a more serious degree. These results suggest that stachyose with an RS3 carrier has better preventative effects on colitis than stachyose alone in mice.

Isolation, characterization, and hepatoprotective effects of the raffinose family oligosaccharides from Rehmannia glutinosa Libosch

This study was aimed to isolate and characterize the raffinose family oligosaccharides (RGOs) from a novel plant source of Rehmannia glutinosa Libosch, and further evaluate whether RGOs can attenuate CCl4-induced oxidative stress and hepatopathy in mice. HPLC analysis showed that RGOs were mainly composed of stachyose (61.7%, w/w), followed by 23.7% raffinose and 7.1% sucrose. Administration of RGOs orally daily in mice for 21 days significantly reduced the impact of CCl4 toxicity on the serum markers of liver damage, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total-cholesterol (TC), and triglycerides (TG). RGOs also increased antioxidant levels of hepatic glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC), and ameliorated the elevated hepatic formation of malonaldehyde (MDA) induced by CCl4 in mice, which coincided with the histological alteration. These findings exhibited the potential prospect of RGOs as functional ingredients to prevent ROS-related liver damage.

New improved method for fructooligosaccharides production by Aureobasidium pullulans

Fructooligosaccharides are prebiotics with numerous health benefits within which the improvement of gut microbiota balance can be highlighted, playing a key role in individual health. In this study, an integrated one-stage method for FOS production via sucrose fermentation by Aureobasidium pullulans was developed and optimized using experimental design tools. Optimization of temperature and agitation speed for maximizing the FOS production was performed using response surface methodology. Temperature was found to be the most significant parameter. The optimum fermentation conditions were found to be 32 °C and 385 rpm. Under these conditions, the model predicted a total FOS production yield of 64.7 gFOS/gsucrose. The model was validated at optimal conditions in order to check its adequacy and accuracy and an experimental yield of 64.1 (±0.0) gFOS/gsucrose was obtained. A significant improvement of the total FOS production yields by A. pullulans using a one-stage process was obtained.

Effects of pH control with phthalate buffers on hot-water extraction of hemicelluloses from spruce wood

Ground spruce wood was extracted with water at 170 °C at four different pH levels (3.8, 4.0, 4.2 and 4.4) achieved by using phthalate buffers. Static batch extractions were carried out in an accelerated solvent extractor (ASE-300). The extracted non-cellulosic carbohydrates, predominantly galactoglucomannans (GGMs), were characterised mainly by sugar unit analysis and molar mass determination. Compared to extraction with plain water, extractions with phthalate buffer solutions gave similar yields of non-cellulosic carbohydrates, but gave up to 70% less monosaccharides, and consequently higher molar masses of extracted GGMs. Moreover, at these pH levels, the hydrolysis of acetyl groups were decreased by 40% compared to extraction with plain water, thus maintaining the water solubility of GGMs. It is concluded that hot water extraction of hemicelluloses in high-molar-mass form (average Mw about 10 kDa) from wood in good yields (8% of wood) demands appropriate control of pH, to a level of about 4.

Effect of macerating enzymes on the oligosaccharide profiles of Merlot red wines

Commercial pectinase preparations are applied in winemaking to improve wine processing and final quality. These preparations contain pectolytic enzyme activities such as polygalacturonases, pectin esterases, pectin lyases, and rhamnogalacturonases. These enzymes modify the polysaccharide and oligosaccharide composition of wines. The influence of various commercial enzyme preparations on wine oligosaccharide composition was studied, on Merlot wines from the Bordeaux area. Wine oligosaccharides were isolated by high-resolution size-exclusion chromatography on a Superdex-30 HR column. The glycosyl residue and glycosyl linkage compositions of the oligosaccharide fractions obtained were determined. The MS spectra of the Merlot oligosaccharide fractions from control and enzyme-treated wines were recorded on an AccuTOF mass spectrometer equipped with an electrospray ionization (ESI) source and a time-of-flight (TOF) mass analyzer. Oligosaccharides in the control wines were partly methylated homogalacturonans, corresponding to smooth regions of pectins, whereas those of the enzyme-treated wines were mostly rhamnogalacturonan-like structures linked with neutral lateral chains, arising from the hairy regions. The enzyme preparations used thus cleaved the rhamnogalacturonan backbone of the hairy zones and demethylated and hydrolyzed the smooth regions. Besides, different structures were detected, depending on the enzyme preparation used, indicating that they contained rhamnogalacturonase activities with different specificities. The oligosaccharide profiles can serve as a marker of enzymatic treatments.

Sandwich-structured enzyme membrane reactor for efficient conversion of maltose into isomaltooligosaccharides

A novel enzyme membrane reactor with sandwich structure has been developed by confining glucosidase between two sheets of ultrafiltration membranes to effectively convert maltose to isomaltooligosaccharides (IMOs). The hydrophilic ultrafiltration membranes, which were prepared by phase inversion method using PES as bulk polymer and Pluronic F127 as both surface modification and pore formation agent, exhibited the desirable enzyme adsorption-resistant property. The scanning electron microscopy (SEM) photographs showed that two sheets of PES/Pluronic F127 membranes were packed tightly and glucosidase was kept in a free state within a nanoscale space. When the weight ratio of Pluronic F127 to PES was 30%, glucosidase could be completely rejected by the membranes. Due to the sandwich structuring of the membrane reactor and the high hydrophilicity of the PES/Pluronic F127 membrane surface, maltose conversion and yield reached 100% and 58% under the optimum experimental conditions (pH 6.0, 50 degrees C), respectively.