In vitro digestion and fermentation characteristics of temulose molasses, a coproduct of fiberboard production, and select temulose fractions using canine fecal inoculum

Chemical composition and in vitro fermentation characteristics of legumes using canine fecal inoculum

Legumes are a popular grain-free alternative carbohydrate source in canine diets, however, information on their fermentative characteristics have not been established. Thus, the objectives of the present study were to 1) quantify the chemical compositions and 2) fermentative profile of select legumes using canine fecal inoculum. Five legume varieties, whole yellow peas (WYP), green lentils (GL), black bean grits (BBG), navy bean powder (NBP), and garbanzo beans, were analyzed and compared to a positive control, beet pulp (BP). Substrates were analyzed for gross energy (GE), dry and organic matter, crude protein (CP), acid hydrolyzed fat, and total dietary fiber (TDF) fractions, beta-glucans, starch-free, and hydrolyzed sugars, as well as fermentative characteristics: pH, short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), total gas, hydrogen, and methane. Substrates then underwent a two-stage in vitro digestion and subsequent fermentation using canine fecal inoculum for 0, 3, 6, 9, and 12 h. All test substrates contained approximately 8% to 9% moisture and 4.5 kcal/g GE. The highest CP content was observed in GL (27%). Analyzed TDF content of test substrates was greatest for WYP (32%) and GL (36%). Total starch content was greatest for GL (58%) and WYP (56%). Sucrose and stachyose were the most predominant free sugars and glucose was the most predominant hydrolyzed sugar among test substrates. After 3 and 6 h of fermentation, a net negative change in pH was observed among most substrates with a net negative change in all substrates after 9 and 12 h. Values for SCFA did not differ among substrates after 3 or 6 h of fermentation with BP and WYP among the greatest acetate (1,656 and 1,765 umol/g, respectively) and propionate production values (157.7 and 126.1, respectively) after 9 h. All substrates produced greater total gas volumes than WYP after 3 h, with no differences observed after any other time points. However, BP hydrogen production values were greater after 9 and 12 h (P < 0.0001; 726,042 and 394,675 ng/g, respectively) with greater methane production values after 12 h (P < 0.0001; 54,291 ng/g) than all test substrates. These data suggest that legumes offer a diverse macronutrient profile and appear to be a source of slowly fermentable fiber, which may have beneficial implications on the ratios of saccharolytic to proteolytic fermentation toward the distal colon.

Inhibition of Salmonella Binding to Porcine Intestinal Cells by a Wood-Derived Prebiotic

Numerous Salmonellaenterica serovars can cause disease and contamination of animal-produced foods. Oligosaccharide-rich products capable of blocking pathogen adherence to intestinal mucosa are attractive alternatives to antibiotics as these have potential to prevent enteric infections. Presently, a wood-derived prebiotic composed mainly of glucose-galactose-mannose-xylose oligomers was found to inhibit mannose-sensitive binding of select SalmonellaTyphimurium and Escherichia coli strains when reacted with Saccharomyces boulardii. Tests for the ability of the prebiotic to prevent binding of a green fluorescent protein (GFP)-labeled S.Typhimurium to intestinal porcine epithelial cells (IPEC-J2) cultured in vitro revealed that prebiotic-exposed GFP-labeled S.Typhimurium bound > 30% fewer individual IPEC-J2 cells than did GFP-labeled S.Typhimurium having no prebiotic exposure. Quantitatively, 90% fewer prebiotic-exposed GFP-labeled S.Typhimurium cells were bound per individual IPEC-J2 cell compared to non-prebiotic exposed GFP-labeled S.Typhimurium. Comparison of invasiveness of S.Typhimurium DT104 against IPEC-J2 cells revealed greater than a 90% decrease in intracellular recovery of prebiotic-exposed S.Typhimurium DT104 compared to non-exposed controls (averaging 4.4 ± 0.2 log₁₀ CFU/well). These results suggest compounds within the wood-derived prebiotic bound to E. coli and S.Typhimurium-produced adhesions and in the case of S.Typhimurium, this adhesion-binding activity inhibited the binding and invasion of IPEC-J2 cells.

An In Vitro Batch-culture Model to Estimate the Effects of Interventional Regimens on Human Fecal Microbiota

The emerging role of the gut microbiome in several human diseases demands a breakthrough of new tools, techniques and technologies. Such improvements are needed to decipher the utilization of microbiome modulators for human health benefits. However, the large-scale screening and optimization of modulators to validate microbiome modulation and predict related health benefits may be practically difficult due to the need for large number of animals and/or human subjects. To this end, in vitro or ex vivo models can facilitate preliminary screening of microbiome modulators. Herein, it is optimized and demonstrated an ex vivo fecal microbiota culture system that can be used for examining the effects of various interventions of gut microbiome modulators including probiotics, prebiotics and other food ingredients, aside from nutraceuticals and drugs, on the diversity and composition of the human gut microbiota. Inulin, one of the most widely studied prebiotic compounds and microbiome modulators, is used as an example here to examine its effect on the healthy fecal microbiota composition and its metabolic activities, such as fecal pH and the fecal levels of organic acids including lactate and short-chain fatty acids (SCFAs). The protocol may be useful for studies aimed at estimating the effects of different interventions of modulators on fecal microbiota profiles and at predicting their health impacts.

Effect of extracted galactoglucomannan oligosaccharides from pine wood (Pinus brutia) on Salmonella typhimurium colonisation, growth performance and intestinal morphology in broiler chicks

An in vitro and in vivo study was conducted to evaluate the fermentability of isolated galactoglucomannan oligosaccharides (GGMs) and the influence of their feeding on shedding and colonisation of Salmonella typhimurium, growth performance and intestinal morphology in broiler chicks. The in vitro data demonstrated that three probiotic lactic acid bacteria namely Lactobacillus casei, L. plantarum and Enterococcus faecium were able to ferment the extracted oligosaccharides and other tested sugars on a basal de Man Rogosa Sharpe media free from carbohydrate. For the in vivo experiment, 144 one-d-old male Ross 308 broiler chicks were divided into 6 experimental treatments (with 4 replicates) including two positive and negative controls which received a basal maize-soybean diet without any additives, supplementation of three levels of isolated GGMs (0.1%, 0.2% and 0.3%) and a commercial mannanoligosaccharide (MOS) at 0.2% to the basal diet. All birds except those in the negative control group were challenged orally with 1 × 10⁸ cfu of S. typhimurium at 3-d post-hatch. The results revealed that challenge with S. typhimurium resulted in a significant reduction in body weight gain, feed intake, villus height, villus height to crypt depth ratio and villus surface area in all of infected chicks. Birds that were given GGMs or MOS showed better growth performance, increased villus height and villus surface area and decreased S. typhimurium colonisation than the positive control birds. GGM at 0.2% level was more effective than the other treatments in improving growth rate as well as gut health of broiler chicks.

In vitro fermentation characteristics of novel fibers, coconut endosperm fiber and chicory pulp, using canine fecal inoculum

The objective of this experiment was to determine the effects of in vitro fermentation of coconut endosperm fiber (CEF), chicory pulp (CHP), and selective blends of these substrates on SCFA production and changes in microbiota using canine fecal inocula. A total of 6 individual substrates, including short-chain fructooligosaccharide (scFOS; a well-established prebiotic source), pectin (PEC; used as a positive control), pelletized cellulose (PC; used as a negative control), beet pulp (BP; considered the gold standard fiber source in pet foods), CEF, and CHP, and 3 CEF:CHP blends (75:25% CEF:CHP [B1], 50:50% CEF:CHP [B2], and 25:75% CEF:CHP [B3]) were tested. Triplicate samples of each substrate were fermented for 0, 8, and 16 h after inoculation. A significant substrate × time interaction (P < 0.05) was observed for pH change and acetate, propionate, butyrate, and total SCFA concentrations. After 8 and 16 h, pH change was greatest for scFOS (-2.0 and -3.0, respectively) and smallest for PC (0.0 and -0.1, respectively). After 16 h, CEF had a greater butyrate concentration than CHP and all the CEF:CHP blends and it was not different than PEC. The substrate × time interaction was significant for bifidobacteria (P < 0.05) and lactobacilli (P < 0.05). After 8 h, bifidobacteria was greatest for BP and lowest for PC (12.7 and 10.0 log10 cfu/tube, respectively). After 16 h, PC had the lowest and scFOS had the greatest bifidobacteria (6.7 and 13.3 log10 cfu/tube, respectively). In general, CEF, CHP, and their blends had similar bifidobacteria populations after 8 and 16 h of fermentation when compared with BP and scFOS. After 16 h, lactobacilli populations were greatest for B1, B2, B3, BP, and scFOS, intermediate for PEC, and lowest for PC (P < 0.05). Overall, our data suggest that CEF had a butyrogenic effect and that CEF, CHP, and their blends had similar bifidobacteria and lactobacilli populations as popular prebiotic and fiber substrates. Future research should investigate the effects of CEF, CHP, and their blends on gastrointestinal health and fecal quality in dogs.

Galactoglucomannan extracted from spruce (Picea abies) as a carbohydrate source for probiotic bacteria

A prebiotic is a nonviable food component that confers a health benefit on the host associated with modulation of the microbiota. Hemicelluloses are the second most common group of polysaccharides in nature and they occur in plant cell walls. The predominant hemicellulose in softwood species is galactoglucomannan, and based on its chemical structure and information available about similar saccharides, galactoglucomannan may be postulated to have prebiotic properties. In this study we demonstrated that Bifidobacterium species are able to ferment hemicellulose-derived saccharides. Significant stimulatory effects on the growth rates of bifidobacteria were found when galactoglucomannan or its hydrolysis products were present. Bifidobacterium animalis subsp. lactis strain Bb12, a commonly used probiotic, was able to adapt to the galactoglucomannan leading to more efficient utilization of hemicellulose-derived saccharides. Our study demonstrates prebiotic properties for galactoglucomannan and warrants the next step, that is, characterization of the effects of galactoglucomannan in food.

Chemical composition and bioactivities of a water-soluble polysaccharide from the endodermis of shaddock

The chemical composition of shaddock (Citrus paradisi) mainly consisted of polyphenols, proteins and polysaccharides. However, polysaccharides from shaddock materials have received much less consideration than polyphenols. Herein, a water-soluble neutral polysaccharide from the endodermis of shaddock was isolated and showed good bioactivities. Crude polysaccharides from the endodermis of shaddock (EPS) was extracted with hot water and separated on a DEAE Sepharose FF gel filtration column to obtain NEPS. The IR and UV spectra of NEPS showed that NEPS was mainly composed of polysaccharide and there are no proteins existing in NEPS. The DPPH radical scavenging and reducing power of NEPS are much lower than those of crude EPS; however, Citrus flavonoids significantly improved the DPPH radical scavenging potential and reducing power of NEPS. The crude EPS (5mg/mL) showed a similar inhibitory effect (77.92±5.03%) with NEPS (5 mg/mL) (74.63±4.71%) on α-amylase.

Manufacture and properties of bifidogenic saccharides derived from wood mannan

Pinus pinaster wood samples were subjected to double hydrothermal processing. The liquors coming from the second stage, containing soluble saccharides of polymeric or oligomeric nature from hemicelluloses (POHs), were subjected to membrane processing (operating in discontinuous diafiltration) for refining and fractionation. Refined POH fractions were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry and chromatographic techniques. The most complex POH component was made up of 14 hexoses and contained 4 acetyl groups. The fermentability of purified POHs by human fecal inocula was assessed by measuring both carbon source consumption and formation of short-chain fatty acids. The bifidogenic ability of POHs was confirmed by fluorescence in situ hybridization. The stimulatory effects on the bifidobacterial population reached by POHs were of the same order as those obtained with commercial fructooligosaccharides.

Galactoglucomannan Oligosaccharides (GGMO) from a molasses byproduct of pine ( Pinus taeda ) fiberboard production

"Temulose" is the trade name for a water-soluble molasses produced on a large scale (300-400 tonnes per year) as a byproduct of the fiberboard industry. The feedstock for Temulose is predominantly a single species of pine ( Pinus taeda ) grown and harvested in stands in southeastern Texas. Because of the method of production, the molasses was predicted to consist of water-soluble hemicelluloses, mainly arabinoxylan-type and galactoglucomannan-type oligosaccharides, plus minor components of lignin, but no detailed structural study had been reported. The structure and composition of the molasses has now been deduced by a combination of MALDI-TOF mass spectrometry, size exclusion chromatography, proton and (13)C NMR techniques, and classic carbohydrate analysis. Limited acid hydrolysis released a series of galactoglucomannan oligosaccharides (GGMO) that were selectively recovered from the acid-labile arabinogalactan by precipitation with ethanol. The precipitate was named "Temulose brown sugar" because of its appearance, and is shown to consist of GGMO with a degree of polymerization (DP) from 4 to 13, with the major component being DP 5-8. The structure of these oligosaccharides is a β-1,4-linked backbone of Man and Glc residues, with occasional α-1,6 branching by single galactosyl units.