Low-fiber Control Research Articles

Unveiling the influence of adaptation time on xylanase and arabinoxylan-oligosaccharide efficacy: a study on nutrient digestibility, viscosity, and scanning electron microscopy in the small and large intestine of growing pigs fed insoluble fiber.

The experiment objective was to evaluate the impact of xylanase over time on viscosity and digestibility in growing pigs fed corn-based fiber. Twenty gilts with an initial body weight of 30.6 ± 0.2 kg (n = 5 per dietary treatment) were fitted with t-cannulae in the medial jejunum and terminal ileum, housed individually, and randomly assigned to one of four dietary treatments: low-fiber control (LF) with 10.4% total dietary fiber (TDF), 30% corn bran high-fiber control (HF; 26.4% TDF), HF + 100 mg xylanase/kg (XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg arabinoxylan-oligosaccharide/kg (AX). Gilts were limit fed for three 17 d periods (P1, P2, P3); each included 5 d adaptation, 2 d fecal collection, 3 d ileal collection, 3 d jejunal collection, and 4 d related rate of passage study. Data were analyzed as repeated measures using a linear mixed model with surgery date as a random effect, and dietary treatment, period, and their interaction as fixed effects. Jejunal and ileal digesta viscosity did not differ among dietary treatments or periods (P > 0.10). There was a dietary treatment × period interaction for the apparent jejunal digestibility (AJD) of dry matter (DM), gross energy (GE), insoluble dietary fiber (IDF), neutral detergent fiber (NDF), total arabinoxylan (T-AX), total non-starch polysaccharide (T-NSP), and TDF (P≤ 0.05). In P1, LF had the greatest AJD of DM (15.5%), and relative to HF and AX, XY decreased it (9.3%, 10.1 %, and 6.3%, respectively). In P2, the AJD of DM in XY was greater than HF (11.7% vs. 9.1%) but did not differ from AX (10.5%). Relative to HF, in P3, XY increased AJD of DM (11.7 vs 15.3%), and AX decreased it (7.2%). For the AJD of NDF, AX performed intermediately in P1; in P2, relative to HF, XY, and AX increased the AJD of NDF (8.4%, 13.1%, and 11.7%, respectively), and in P3, XY, and LF did not differ (13.6 vs. 14.4%). A similar response was observed for the AJD of IDF and TDF, except for XY having the greatest AJD of IDF, T-AX, T-NSP, and TDF in P3 (P < 0.05). Compared to LF, irrespective of period, HF decreased the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of IDF, TDF, and NDF (P < 0.05). Relative to HF, XY partially mitigated this effect, improving the AID and ATTD of TDF, IDF, and NDF (P < 0.05). Increased corn-based fiber decreased nutrient digestibility, but XY partially mitigated that effect in the small intestine through enhanced fiber digestibility when given sufficient adaptation time.

Using cereal to increase dietary fiber intake to the recommended level and the effect of fiber on bowel function in healthy persons consuming North American diets

Background:Dietary fiber intake remains low despite increasing evidence for its health benefits, including laxation. Objective:We aimed to assess the effects of increasing fiber intake on bowel habits and gastrointestinal tolerance in healthy persons consuming a typical Canadian or US diet. Design:Under a randomized crossover design, 23 free-living participants consumed a typical Canadian or US diet (35% fat, 12 g fiber/d) and received 25.0–28.7 g fiber/d from each of 5 breakfast cereals: All-Bran (AB), Bran Buds with Corn (BBC), Bran Buds with Psyllium (BBP), BBC with viscous fiber blend (VFB), or a low-fiber control for 3 wk, with each study arm separated by a washout of ≥1 wk. Seven-day stool collections and a symptom diary were obtained during the last week of each study arm. Results:All study cereals induced significant (P < 0.05) increases in fecal bulk from the control diet at 128 ± 38 g to 199 ± 56, 199 ± 57, 247 ± 87, and 197 ± 63 g with consumption of AB, BBC, BBP, and VFB, respectively; less intestinal transit time; and significantly (P < 0.05) greater bowel movement frequency. Despite the increased activity of the bowel, a positive level of comfort was maintained. BBP was more effective than other cereals in terms of increasing fecal wet weight (P < 0.05). Conclusion:Water-insoluble dietary fibers (ie, AB and BBC) and their mixtures with water-soluble fibers (ie, BBP and VFB) in the form of breakfast cereals (2.5 servings/d) proved to be a practical way of increasing fiber intake to recommended levels, while maintaining a good level of tolerance.

Influence of dietary fibre on nutrient digestibility and energy utilisation in growing pigs fed diets varying in soluble and insoluble fibres from co-products

The co-products from the industry are used to reduce costs in pig diets. However, the co-products used in pig diets are limited because of a high fibre content which is not digested by endogenous enzymes and is resistant to degradation in the small and large intestines. The aim of this study was to investigate digestibility of nutrients and energy, and energy utilisation in pigs fed diets with various soluble and insoluble dietary fibre (DF) from co-products. The experiment was performed as a 4 × 4 Latin square design (four diets and four periods) using four growing pigs (66.2 ± 7.8 kg) surgically fitted with a T-cannula in the end of the small intestine. The pigs were fed four experimental diets: low-fibre control (LF), high-fibre control (HF), high-soluble fibre (HFS) and high-insoluble fibre (HFI) diets. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of ash, organic matter, CP, fat, carbohydrates, starch and non-starch polysaccharides (NSP) divided into cellulose and soluble and insoluble non-cellulosic polysaccharide residues were measured using chromic oxide as marker. The recovery of total solid materials, organic matter and total carbohydrates in ileal digesta in pigs fed the HF and HFS diets was higher than in pigs fed LF and HFI, whereas recovery of organic matter and total carbohydrates in faecal materials in the HFS diet was lowest (P < 0.05). AID of organic matter, total carbohydrates and starch was lowest for HFS diet (P < 0.05). ATTD of organic matter and CP was higher for LF diet compared with other diets (P < 0.05), whereas total NSP, cellulose and non-cellulosic polysaccharides residues were highest for HFS diet (P < 0.05). Lactic acid in ileal digesta was influenced by dietary composition (P < 0.05) whereas neither type nor level of DF affected short chain fatty acids. The digestible energy, metabolisable energy, net energy and retained energy intake were similar among diets without influence of DF inclusion (P > 0.05). The metabolisable energy:digestible energy ratio was lower when feeding the HFS diet because of a higher fermentative methane loss. Faecal nitrogen and carbon were positively correlated with DM intake and insoluble DF in the diets (P < 0.05), but nitrogen and carbon (% of intake) were similar among diets. The present findings suggest that high-DF co-products can be used as ingredients of pig diets when features of DF are considered.

Effect of Kithul Palm (Caryota urens) Fiber on Subjective Satiety and Food Intake of Normal and Overweight Women in Sri Lanka

Dietary fiber plays prominent role in satiety characteristics of meals. Kithul palm flour is a conventional food ingredient consumed in Sri Lanka, believed having superior satiety characteristics. This study aimed to find the subjective satiety characteristics of Kithul flour meal compared to soluble fiber meal (Psyllium) and low fiber meal. Three arm, single blinded, cross over placebo controlled study was designed with three isocaloric treatments (carbohydrate 55%, fat 30% and protein 15%) having same energy density (~1 kcal/g). Satiety characteristics after ingestion of treatment meal were recorded using Visual Analog Scale (VAS). The Kithul flour meal had significant reduction in hunger (P=0.0025), increment in fullness (P=0.0408), reduction in desire to eat (P&lt;0.0001), and reduced prospective food consumption (P&lt;0.0001) values compared to the Psyllium meal. Further, Kithul flour meal had increased fullness (P=0.0388), reduced desire to eat (P=0.0002), and reduced prospective food consumption (P&lt;0.0001) compared to the low-fiber control meal. Kithul flour meal showed superior satiety results in overweight women compared to normal weight women.

The influence of xylanase on the fermentability, digestibility, and physicochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs.

In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. A total of 3 replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF + 100 mg xylanase/kg (HF + XY [Econase XT 25P; AB Vista, Marlborough, UK]) providing 16,000 birch xylan units/kg; and HF + 50 mg arabinoxylan-oligosaccharide (AXOS) product/kg (HF + AX [XOS 35A; Shandong Longlive Biotechnology, Shandong, China]) providing AXOS with 3–7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P < 0.01). Relative to HF, HF + XY improved the AID of GE, CP, and NDF (P < 0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P < 0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P = 0.031). Relative to HF, HF + XY improved cecal disappearance of DM (162 vs. 98 g; P = 0.008) and NDF (44 vs. 13 g; P < 0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P < 0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF + XY decreased ileal viscosity compared with HF (P < 0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.

Effect of fiber source and carbohydrase enzyme on chukar partridge growth performance, blood characteristics, digestive enzyme activity, cecal microbial population and ileal morphology

Effects of fiber source with various particle size and carbohydrase enzyme on growth criteria, carcass and blood characteristics, digestive enzyme activity, cecal microbial population and ileal morphology of chukar partridge were evaluated for a total period of 90 days. 300 day-old partridge were randomly allotted to a 5 × 2 factorial arrangement with 4 different fiber inclusion with different mean particle size (MPS) (none; rice hulls (RH) (711 ± 1.8 μm); wheat straw (WS) Coarse (3211 ± 1.2 μm); wheat straw Fine (755 ± 1.9 μm); and wheat bran (WB) (767 ± 1.8 μm)) along with a low-fiber control diets and two levels of carbohydrase enzyme (0 or 50 mg/kg). There were 10 treatments and 5 pens with 6 partridge chicks per each treatment. The results indicated that fiber inclusion regardless of fiber source significantly increased body weight (BW) of birds during the whole experimental period (P < 0.01). Among the fiber sources, the highest BW attained when fine WS and WB was incorporated into the low fiber diet (P < 0.01). The effect of enzyme on body weight was significant on days 60 and 90. Moreover, there were interactive effects (P< 0.01) between fiber sources and enzyme on BW during the trial. Feed intake significantly (P< 0.001) increased at starter (30 days) phase of trial by inclusion of fiber to control diet, but no significant differences were noted after on days 60 and 90. Enzyme addition had no effect on feed intake and also no interactive effect was observed between fiber source and enzyme for feed intake. Feed conversion ratio (FCR) was reduced by inclusion of fiber into control low fiber diet especially at late stage of rearing period (P< 0.05). Plasma uric acid concentration was reduced by inclusion of fiber on day 28 (P< 0.05). Inclusion of fine WS increased plasma triglyceride and very low-density lipoprotein cholesterol (VLDL-C) concentration on day 90 (P< 0.05). There were interactive effects (P< 0.05) between fiber sources and enzyme on total cholesterol and very low-density lipoprotein cholesterol (LDL-C) cholesterol on day 90. Jejunum and ileum relative weight were reduced by inclusion of fiber to control diet and the effect was more pronounced for coarse wheat straw (P< 0.05). Duodenum and ileum weight were increased by addition of enzyme to diets (P< 0.05). Fiber inclusion regardless of fiber source and particle size significantly (P< 0.01) reduced duodenum, jejunum and ileum relative length. Addition of coarse WS and RH into the low fiber diet significantly increased alkaline protease, trypsin and α-amylase activity (P< 0.01). There were interactive effects (P< 0.05) between fiber sources and enzyme on digestive enzyme activity (P< 0.01). Enzyme addition reduced trypsin activity (P< 0.05). Ceca E. coli population was increased when fiber sources were incorporated into the low fiber diet (P< 0.05). Villi length, crypt depth and villi to crypt ratio were reduced (P< 0.01) considerably regardless of fiber source compared to the low fiber diet. Inclusion of coarse WS increased and RH reduced (P< 0.01) submucosa, lamina propria and epithelial cells layer thickness compared to the low fiber diet. The results confirmed that partridge growth performance was improved by inclusion of fiber. Results obtained from current trial suggest that the fiber is a very important part of partridge diets which could improve the performance with advancing age especially in long-lived partridge.

Xylanase Supplementation Modulates the Microbiota of the Large Intestine of Pigs Fed Corn-Based Fiber by Means of a Stimbiotic Mechanism of Action.

This research tested the hypothesis that xylanase modulates microbial communities within the large intestine of growing pigs fed corn-based fiber through a stimbiotic mechanism(s) of action (MOA). Sixty gilts were blocked by initial body weight, individually housed, and randomly assigned to one of four dietary treatments (n = 15): a low-fiber (LF) control, a high-fiber (HF) control containing 30% corn bran, HF+100 mg/kg xylanase (HF+XY), and HF+50 mg/kg arabinoxylan-oligosaccharide (HF+AX). Pigs were fed dietary treatments for 46 days. On day 46, pigs were euthanized, and mucosa and lumen contents were collected from the cecum and the colon. The V4 region of 16S rRNA genes was sequenced and clustered into 5,889, 4,657, 2,822, and 4,516 operational taxonomic units (OTUs), in the cecal contents and mucosa and colonic contents and mucosa, respectively. In cecal contents, HF+XY increased measures of α-diversity compared to LF (p < 0.001). Relative to LF, HF increased the prevalence of 44, 36, 26, and 8, and decreased 19, 9, 21, and 10, of the 200 most abundant OTUs from the cecal contents and mucosa and colonic contents and mucosa, respectively (Q < 0.05). Compared to LF, HF increased the abundance of OTUs from the Treponema_2, Ruminococcus_1 genera, from the Lachnospiraceae, Ruminococcaceae, and Prevotellaceae families. In contrast, relative to LF, HF decreased Turicibacter and Lactobacillus in the cecal contents, and Megasphaera and Streptococcus in the mucosa. Relative to HF, HF+XY increased 32, 16, 29, and 19 and decreased 27, 11, 15, and 10 of the 200 most abundant OTUs from the cecal contents and mucosa and colonic contents and mucosa, respectively (Q < 0.05). The addition of xylanase to HF further increased the abundance of OTUs from the Lachnospiraceae and Ruminococcaceae families across the large intestine. Compared to HF, HF+XY increased the abundance of Lactobacillus, Bifidobacterium, and Faecalibacterium among all locations (Q < 0.05). However, HF+AX did not increase the prevalence of these genera in the large intestine. Supplementing xylanase to HF increased hidden-state predictions of microbial enzymes associated with arabinoxylan degradation, xylose metabolism, and short-chain fatty acid production. These data suggest xylanase elicits a stimbiotic MOA in the large intestine of pigs fed corn-based fiber.

Xylanase modulates the microbiota of ileal mucosa and digesta of pigs fed corn-based arabinoxylans likely through both a stimbiotic and prebiotic mechanism.

The experimental objective was to characterize the impact of insoluble corn-based fiber, xylanase, and an arabinoxylan-oligosaccharide on ileal digesta and mucosa microbiome of pigs. Three replicates of 20 gilts were blocked by initial body weight, individually-housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF), a 30% corn bran high-fiber control (HF), HF+100 mg/kg xylanase (HF+XY), and HF+50 mg/kg arabinoxylan oligosaccharide (HF+AX). Gilts were fed their respective treatments for 46 days. On day 46, pigs were euthanized and ileal digesta and mucosa were collected. The V4 region of the 16S rRNA was amplified and sequenced, generating a total of 2,413,572 and 1,739,013 high-quality sequences from the digesta and mucosa, respectively. Sequences were classified into 1,538 mucosa and 2,495 digesta operational taxonomic units (OTU). Hidden-state predictions of 25 enzymes were made using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUST2). Compared to LF, HF increased Erysipelotrichaceae_UCG-002, and Turicibacter in the digesta, Lachnospiraceae_unclassified in the mucosa, and decreased Actinobacillus in both (Q<0.05). Relative to HF, HF+XY increased 19 and 14 of the 100 most abundant OTUs characterized from digesta and mucosa, respectively (Q<0.05). Notably, HF+XY increased the OTU_23_Faecalibacterium by nearly 6 log2-fold change, compared to HF. Relative to HF, HF+XY increased genera Bifidobacterium, and Lactobacillus, and decreased Streptococcus and Turicibacter in digesta (Q<0.05), and increased Bifidobacterium and decreased Escherichia-Shigella in the mucosa (Q<0.05). Compared to HF, HF+AX increased 5 and 6 of the 100 most abundant OTUs characterized from digesta and mucosa, respectively, (Q<0.05), but HF+AX did not modulate similar taxa as HF+XY. The PICRUST2 predictions revealed HF+XY increased gene-predictions for enzymes associated with arabinoxylan degradation and xylose metabolism in the digesta, and increased enzymes related to short-chain fatty acid production in the mucosa. Collectively, these data suggest xylanase elicits a stimbiotic and prebiotic mechanism.

132 A longer adaptation time increased xylanases efficacy in improving dry matter and fiber digestibility in the small intestine of growing pigs fed insoluble fiber

Abstract The objective of this experiment was to investigate xylanase efficacy and impact of adaptation time on nutrient utilization in the small intestine of growing pigs fed insoluble fiber. Twenty gilts (30.6 ± 0.2 kg BW; n=5 per treatment) were surgically fitted with t-cannulae in the medial jejunum (292 ± 12 cm distal to the pyloric sphincter) and in the terminal ileum, housed individually, and randomly assigned to one of four dietary treatments: a low-fiber control (LF; 7.3% NDF), a 30% corn bran high-fiber control (HF; 27.2% NDF), HF + 100 mg xylanase/kg (HF+XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg arabinoxylan-oligosaccharide/kg (HF+AX; 3-7 degrees of polymerization). Gilts were limit fed for three 17 d periods (P1, P2, or P3). Each period included 5 d of adaptation, 2 d of fecal collections, 3 d of ileal collections, and 3 d of jejunal collections. Data were analyzed as repeated records using a linear mixed model (PROC Mixed, SAS 9.4) with surgery date as a random effect, and treatment, period, and their interaction as fixed effects. There tended to be a treatment by period interaction for the apparent jejunal digestibility (AJD) of DM driven by HF+XY improving digestibility over time when compared to HF. Xylanase improved AJD of DM by 21.9% (12.04% vs. 15.4%) in P2, and 40.5% (12.18% vs. 20.49%) in P3 (Treatment Period, P = 0.054). Xylanase supplementation improved AJD of NDF, compared to HF, in P2 by 36.3% (13.7% vs. 21.5%), and in P3 by 28.6% (17.7 vs 24.8%; Treatment Period, P = 0.031). Supplementing xylanase improved the apparent ileal digestibity (AID) of DM over HF in P1 by 4.4%, in P2 by 3.7% (73.91% vs. 76.2 %), and in P3 by 7.4% (75.04% vs. 80.84%; Treatment Period P=0.043). In conclusion xylanase efficacy improved with increased adaptation time.

133 Supplementing xylanase increased the digestibility of non-starch polysaccharides, particularly arabinoxylan, in diets high in insoluble corn fiber fed to swine with a 36-d dietary adaptation period

Abstract Xylanase should increase arabinoxylan digestibility in swine, but the responses in corn-based diets are inconsistent. The experimental objective was to investigate xylanase efficacy in growing pigs fed a diet high in insoluble corn fiber and afforded a longer adaptation period than typically reported in the literature. Sixty gilts (25.4 ± 0.9 kg BW; L337 × Camborough), were blocked by weight, housed individually, and randomly assigned to one of four dietary treatments: a low-fiber control [LF; 6.9% non-starch polysaccharides (NSP)], a 30% corn bran high-fiber control (HF; 17.6% NSP), HF + 100 mg xylanase/kg (HF+XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg arabinoxylan-oligosaccharide/kg (HF+AX; 3-7 degrees of polymerization). Diets contained 0.5% CrO3. Gilts were fed ad libitum for 36 d, followed by 10-d of limit feeding (80% of average ad libitum intake) and were housed in metabolism crates. On d 46, pigs were necropsied and ileal, cecal, and colonic digesta were collected; ileal digesta was pooled within replicate for NSP analysis (n=6 per treatment). Data were analyzed as a linear mixed model using replicate and block as random effects, and treatment as a fixed effect. Compared to LF, the HF diet reduced (P&amp;lt; 0.01) apparent ileal digestibility (AID) of total NSP (32.7 vs. 16.3%), insoluble NSP (50.0 vs. 21.5%), and insoluble arabinoxylan (29.8 vs. 15.4%). Xylanase (HF+XY vs. HF) increased (P&amp;lt; 0.01) AID of total NSP by 39.8% (27.1 vs. 16.3%) and insoluble NSP by 34.0%. This may be attributed to xylanase increasing AID of total arabinoxylan by 54.5% over HF, 44.5% over LF, and 56.9% over HF+AX (33.0, 15.1, 18.3, and 14.2%, respectively; P=0.02). In conclusion, increasing insoluble fiber reduces NSP digestibility, but xylanase can increase AID of arabinoxylan and NSP. Supplementing an arabinoxylan-oligosaccharide, a potential release product of the xylanase, did not increase NSP digestibility.

PSVIII-3 Can the fermentation of insoluble corn fiber be improved in the pig? – An investigation into the in vivo mode of action of xylanase

Abstract Xylanase may improve fermentability of corn co-products through the alteration of hemicellulose, but the mode of action (MOA) is incompletely understood. The experimental objective was to investigate the in vivo MOA of xylanase in growing pigs fed insoluble fiber. Sixty gilts (25.4 ± 0.9 kg BW; L337 X Camborough), were blocked by weight, housed individually, and randomly assigned to one of four dietary treatments: a low-fiber control (LF; 8.45% NDF), a 30% corn bran high-fiber control (HF; 24.5% NDF), HF + 100 mg of xylanase/kg (HF+XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg of arabinoxylan-oligosaccharide/kg (HF+AX; 3-7 degrees of polymerization). Gilts were fed ad libitum for 36 d, followed by 10-d of metabolism crate housing and limit feeding (80% of average ad libitum intake). On d 46, pigs were necropsied and ileal, cecal, and colonic digesta were collected for short-chain fatty acid (SCFA) analysis, and 16s rRNA gene amplicon sequencing. Data were analyzed as a mixed model with random effects of replicate and block, and fixed effect of treatment. Differences in individual operational taxonomic units (OTUs) were compared using Linear Discriminant Analysis Effect Size. Acetate, propionate, butyrate, and total SCFA in the ileum did not differ (P &amp;gt;0.05), but HF+XY had 10 significantly different OTUs compared to HF in the ileum (P&amp;lt; 0.05). In the cecum, compared to LF, HF reduced total SCFA concentration (91.7 vs. 82.8 mM/L; P&amp;lt; 0.01). However, HF+XY and HF+AX increased total SCFA concentration by 23% and 12% over HF, respectively (P&amp;lt; 0.05). This is likely due to increased cecal acetate concentration (54.0, 53.2, 74.4, 61.2 mM/L for LF, HF, HF+XY, and HF+AX, respectively; P&amp;lt; 0.01). Total colonic SCFA concentration did not differ (P=0.72), but xylanase increased molar proportions of butyrate (P&amp;lt; 0.01). One MOA of xylanase could be the release of fermentable substrates from insoluble fiber.

Fibre supplementation to pre-weaning piglet diets did not improve the resilience towards a post-weaning enterotoxigenic E. coli challenge.

Dietary fibre (DF) is implicated in gastrointestinal health of weaned piglets, either through its physiochemical properties, through modulation of gut microbiota and (or) improved gut integrity. We aimed to study the effect of DF enriched supplemental diets fed to suckling piglets ('creep feed') on health and performance after weaning when challenged with an enterotoxigenic E. coli (ETEC). Seventy-two piglets originating from 28 litters had been fed four creep diets, that is a low-fibre control (CON); a diet containing 2% long-chain arabinoxylans from wheat (lc-AXOS) or 5% purified cellulose (CELL) or a diet containing the high fermentable and the low-fermentable fibre source (i.e. 2% lc-AXOS and 5% CELL). Upon weaning, piglets were individually housed and all fed the same diet. On days 7, 8 and 9, animals received an oral dose of ETEC (5ml containing 107 to 108 CFU/ml). Besides growth performance, faecal and skin scores were recorded daily. Gut permeability was assessed by urinary excretion of Co-EDTA prior and post-ETEC challenge. Repeated measures in time were statistically evaluated with generalized linear mixed models. We used a binominal distribution for evaluating the faecal and skin scores. Feed intake and body weight gain did not differ between treatments (p>.05). Piglets on CELL decreased gain:feed ratio in week 2+3week compared to CON (p=.035). Prior to ETEC challenge, gut permeability tended to increase for lc-AXOS (p=.092). Moreover, lc-AXOS as main effect increased intestinal permeability before ETEC challenge (p=.013), whereas the low-fermentable fibre lead to elevated intestinal permeability after ETEC challenge (p=.014). The incidence of diarrhoea was higher for lc-AXOS+CELL compared with lc-AXOS (p=.036), while skin condition was unaffected. In conclusion, neither the high fermentable nor the low-fermentable fibre source improved post-weaning growth or gastrointestinal health of the piglets.

Potato Fibers Have Positive Effects on Subjective Appetite Sensations in Healthy Men, but Not on Fecal Fat Excretion: A Randomized Controlled Single-Blind Crossover Trial.

Dietary fibers can affect appetite and gut metabolism, but the effect of the novel potato fibers FiberBind and rhamnogalacturonan I (RG-I) is unknown. We, therefore, aimed to investigate the effect of daily intake of FiberBind and RG-I on appetite sensations and fecal fat excretion. In a single-blinded, randomized, three-way crossover trial, wheat buns with FiberBind, RG-I, or low fiber (control) were consumed by 18 healthy men during a 21-day period. Appetite sensation and blood samples during a 3 h meal test, fecal fat content, and ad libitum energy intake were assessed after each period. Compared to RG-I and control, FiberBind caused a higher composite satiety score (6% ± 2% and 5% ± 2%), lower prospective food consumption (5% ± 2% and 6% ± 2%), and lower desire to eat (7% ± 3% and 6% ± 3%) (all p < 0.05). FiberBind also caused higher satiety (6% ± 2%) and fullness (9% ± 3%) compared to RG-I (all p < 0.01). No effects on fecal fat excretion or energy intake were found. The RG-I fiber caused higher postprandial glucose concentration compared to FiberBind (p < 0.05) and higher insulin concentration at 180 min compared to control (p < 0.05). Compared to the control, RG-I and FiberBind lowered peak insulin concentration (both p < 0.05) and delayed time to peak for glucose (both p < 0.05). In conclusion, FiberBind intake could be beneficial for appetite regulation, but neither FiberBind nor RG-I affected fecal fat excretion or energy intake.

Xylanase increased the energetic contribution of fiber and improved the oxidative status, gut barrier integrity, and growth performance of growing pigs fed insoluble corn-based fiber

The experimental objective was to investigate the impact of xylanase on the bioavailability of energy, oxidative status, and gut function of growing pigs fed a diet high in insoluble fiber and given a longer adaptation time than typically reported. Three replicates of 20 gilts with an initial body weight (BW) of 25.43 ± 0.88 kg were blocked by BW, individually housed, and randomly assigned to one of four dietary treatments: a low-fiber control (LF) with 7.5% neutral detergent fiber (NDF), a 30% corn bran without solubles high-fiber control (HF; 21.9% NDF), HF + 100 mg/kg xylanase (HF + XY; Econase XT 25P), and HF + 50 mg/kg arabinoxylan-oligosaccharide (HF + AX). Gilts were fed ad libitum for 36 d across two dietary phases. Pigs and feeders were weighed on days 0, 14, 27, and 36. On day 36, pigs were housed in metabolism crates for a 10-d period, limit fed (80% of average ad libitum intake), and feces and urine were collected the last 72 h to determine the digestible energy (DE) and metabolizable energy (ME). On day 46, serum and ileal and colonic tissue were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment, time, and treatment × time as fixed effects. There was a significant treatment × time interaction for BW, average daily gain (ADG), and gain to feed (G:F; P < 0.001). By design, BW at day 0 did not differ; at day 14, pigs fed LF were 3.5% heavier, and pigs fed HF + XY, when compared with HF, were 4% and 4.2% heavier at days 27 and 36, respectively (P < 0.001). From day 14 to 27 and day 27 to 36, when compared with HF, HF + XY improved ADG by 12.4% and 10.7% and G:F by 13.8% and 8.8%, respectively (P < 0.05). Compared with LF, HF decreased DE and ME by 0.51 and 0.42 Mcal/kg, respectively, but xylanase partially mitigated that effect by increasing DE and ME by 0.15 and 0.12 Mcal/kg, over HF, respectively (P < 0.05). Pigs fed HF + XY had increased total antioxidant capacity in the serum and ileum (P < 0.05) and tended to have less circulating malondialdehyde (P = 0.098). Pigs fed LF had increased ileal villus height, and HF + XY and HF + AX had shallower intestinal crypts (P < 0.001). Pigs fed HF + XY had increased ileal messenger ribonucleic acid abundance of claudin 4 and occludin (P < 0.05). Xylanase, but not AX, improved the growth performance of pigs fed insoluble corn-based fiber. This was likely a result of the observed increase in ME, improved antioxidant capacity, and enhanced gut barrier integrity, but it may require increased adaptation time to elicit this response.

160 Can growth performance, digesta characteristics, and oxidative status of swine fed diets high in insoluble fiber be improved? An investigation into the mode of action of xylanase

Abstract Xylanase may improve the utilization of insoluble fiber by the pig, but its mode of action (MOA) is incompletely understood. The experimental objective was to investigate xylanase MOA in vivo in growing pigs fed a diet higher in insoluble fiber. Sixty gilts (n = 15 pigs/treatment; 25.43 ± 0.88 kg BW; L337 X Camborough, PIC, Hendersonville, TN) were blocked by weight, housed individually, and randomly assigned to one of four dietary treatments: a low-fiber control (LF; NDF=8.45%), a 30% corn bran higher-fiber control (HF; NDF=24.5%), HF + 100 mg xylanase/kg (HF+XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg arabinoxylan-oligosaccharide/kg (HF+AX; 3–7 degrees of polymerization). Gilts were fed ad libitum for 36 d, followed by a 10-d period of being limit fed (80% of average ad libitum intake) and housed in metabolism crates for use in a related study. Pigs and feeders were weighed on d 0 and 36. On d 46, pigs were necropsied and ileal, cecal, and colonic digesta pH were measured; serum was collected for malondialdehyde (MDA) and total antioxidant capacity (TAC) analysis. Data were analyzed using PROC MIXED (SAS; 9.4) as a randomized complete block design with pig as the experimental unit, block and replicate as random effects, and treatment as a fixed effect. Insoluble fiber reduced ADG (858 vs. 698 g/d; LF vs. HF, P &lt; 0.001) and GF (0.433 vs. 0.353; LF vs. HF, P &lt; 0.001), but not ADFI (P &gt; 0.05). Xylanase, but not arabinoxylan-oligosaccharide, when compared to HF, improved ADG (762 vs. 698 g/d; P &lt; 0.05), GF (0.382 vs. 0.353; P &lt; 0.05), and final BW (P &lt; 0.05). Cecal and colonic pH did not differ (P &gt; 0.05), but LF and HF+XY reduced ileal pH (P &lt; 0.05). Xylanase supplementation increased serum TAC (P &lt; 0.05), and tended to reduce MDA (P = 0.098). In conclusion, xylanase supplementation improved insoluble fiber utilization. The MOA could include mitigation of reactive oxygen species.

PSVII-10 Xylanase improved the nutrient and energy digestibility of diets high in insoluble corn fiber fed to swine following a 36-d dietary adaptation period

Abstract The efficacy of xylanase in practical swine diets is inconsistent and poorly understood. The experimental objective was to investigate the efficacy of xylanase in growing pigs fed a diet high in insoluble corn fiber and afforded a longer adaptation period than typically reported in the literature. Sixty gilts (25.43 ± 0.88 kg BW; L337 X Camborough, PIC, Hendersonville, TN; n = 15 per treatment), were blocked by weight, housed individually, and randomly assigned to one of four dietary treatments: a low-fiber control (LF; 8.45% NDF), a 30% corn bran high-fiber control (HF; 24.5% NDF), HF + 100 mg/kg of xylanase (HF+XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg/kg of arabinoxylan-oligosaccharide (HF+AX; 3-7 degrees of polymerization). Diets contained 0.5% chromium (III) oxide. Gilts were fed ad libitum for 36 d, followed by a 7-d period of adaptation to limit feeding (80% of average ad libitum intake) and housing in metabolism crates, followed by 3 d of urine and fecal collection. Data were analyzed using PROC MIXED (SAS; 9.4) as a randomized complete block design with pig as the experimental unit, block and replicate as random effects, and treatment as a fixed effect. Compared to the LF diet, the HF diet reduced the apparent total tract digestibility (ATTD) of DM (88.7 vs. 75.6%), GE (89.0 vs. 77.4%), CP (87.2 vs. 81.8%), NDF (63.3 vs. 44.4%), ADF, and hemicellulose (P = 0.01). Xylanase supplementation, but not arabinoxylan-oligosaccharide, when compared to the HF control diet, improved the ATTD of DM by 3.3% (78.2 vs. 75.6%), GE by 2.2% (79.1 vs. 77.4%), CP by 2.9% (84.2 vs. 81.8%), NDF by 17.5% (53.9 vs. 44.4%), ADF by 16.3% (52.1 vs. 42.9%), and hemicellulose by 16.4% (P &lt; 0.05). These data indicate insoluble fiber reduced nutrient and energy digestibility, but xylanase was effective in partially mitigating that effect.

Whole fruit pulp (mango) and a soluble fibre (pectin) impact bacterial diversity and abundance differently within the porcine large intestine

Effects of diets including a fruit cell-wall matrix (mango) or a soluble cell-wall polymer (pectin), on the porcine large intestine (LI) bacterial community were examined at the caecum (Cae), proximal (PC), mid- (MC), and distal colon (DC), investigating both bacterial composition and metabolic end-products.Pigs were fed one of three diets: Control based on wheat starch, and treatment diets where starch was partially substituted with either 15% mango pulp or 10% pectin.Fermentation end-products were significantly different between diets, and LI sites (P < 0.001). Control-diet fed pigs had lowest SCFA and highest ammonium concentrations. Distally, SCFA concentrations decreased across all diets, resulting in reduced differences between diets. The more complex fibre in the Mango diet promoted increased bacterial diversity within the Cae and PC, compared with pigs fed the Control and Pectin diets. At each site, the order of total species abundance and diversity was Mango > Control > Pectin. Between diet groups, there were distinct community differences. Species abundance that differed per diet included Faecalibacterium prausnitzii (Pectin), and Lactobacillus mucosae (Mango). However, Mango promoted a more stable abundance of F. prausnitzii along the LI, while Pectin resulted in F. prausnitzii abundance being high proximally and low distally. This contrasted with the low fibre Control diet results, where F. prausnitzii was not detectable. This study has shown that although pectin can promote extensive fermentation early in the LI, more prolonged and beneficial effects in the distal LI, including greater microbial species diversity, occur when the diet includes plant material with complex intact plant cell-walls, such as from mango.

Type-4 Resistant Starch in Substitution for Available Carbohydrate Reduces Postprandial Glycemic Response and Hunger in Acute, Randomized, Double-Blind, Controlled Study.

Resistant starch (RS) is a type of dietary fiber that has been acknowledged for multiple physiological benefits. Resistant starch type 4 (RS4) is a subcategory of RS that has been more intensively studied as new types of RS4 emerge in the food supply. The primary aim of this randomized, double-blind, controlled study was to characterize the postprandial glucose response in healthy adults after consuming a high fiber scone containing a novel RS4 or a low fiber control scone without RS4. Secondary aims included assessment of postprandial insulin response, postprandial satiety, and gastrointestinal tolerance. The fiber scone significantly reduced postprandial glucose and insulin incremental areas under the curves (43–45% reduction, 35–40% reduction, respectively) and postprandial glucose and insulin maximum concentrations (8–10% and 22% reduction, respectively). The fiber scone significantly reduced hunger and desire to eat during the 180 min following consumption and yielded no gastrointestinal side effects compared with the control scone. The results from this study demonstrate that a ready-to-eat baked-good, such as a scone, can be formulated with RS4 replacing refined wheat flour to yield statistically significant and clinically meaningful reductions in blood glucose and insulin excursions. This is the first study to report increased satiety after short-term RS4 intake, which warrants further investigation in long-term feeding studies.

Resistant Starch Alters Gut Microbiota and Reduces Uremic Retention Solutes in Rats with Adenine‐induced Chronic Kidney Disease

Chronic kidney disease (CKD) is characterized by impaired urinary excretion and accumulation of waste products in the body. Recent observations found patients with CKD have an altered gut microbiome. We hypothesized that supplementation with the fermentable dietary fiber, resistant starch (RS) would alter the gut microbiota and reduce accumulation of waste products in a CKD-rat model. Male Sprague-Dawley rats (n=9/grp) were fed chow containing 0.7% adenine (w/w) for 1 wk to induce CKD. Adenine forms crystals in kidney tubules leading to occlusion and subsequent retention of uremic solutes. Rats were then placed on a semi-purified low-fiber control diet or 59% RS diet (w/w) for 4 wks. Compared to healthy chow-fed rats, the CKD rats had 65% reduced creatinine clearance; RS significantly improved this by 35% compared to CKD rats. A cecal bacterial survey indicated an increase in Bacteroidetes (by 47%, p<0.001) and decrease in Firmicutes (by 29%, p<0.001) in RS-fed rats. Metabolomics of liver, serum, urine, and cecal contents revealed reductions in many uremic retention solutes; i.e., serum and urine microbial-derived indoxyl-sulfate was decreased (by 36% and 66% vs. CKD rats, p<0.05). These results demonstrate the potential for RS as a dietary treatment for CKD, considering its actions to alter the gut microbiota and reduce accumulation of microbial-derived uremic retention solutes. Funding Danish Council for Strategic Research, USDA-ARS Intramural Project 5306-51530-019-00.

High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control) or high fermentable fiber (amylose maize resistant starch, HAM-RS2) for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.