In vitro production of short-chain fatty acids from resistant starch by pig faecal inoculum

Estimating the contribution of the porcine fecal core microbiota to metabolite production via mathematical modeling and in vitro fermentation

The swine gut microbiota is a complex ecosystem found throughout the gastrointestinal tract, with multiple exchanges with the host and whose composition is linked to both external and internal factors, such as diet or breed. Diet, probiotic, or prebiotic interventions have been designed to boost beneficial host-microbiota interactions, such as the production of anti-inflammatory molecules, or the fermentation of otherwise undigested resources. In parallel, a smaller microbial population, shared among the same host species, independent of external or internal factors, has been described and defined as the "core microbiota." Therapies targeting the core microbiota could possibly lead to more precise and long-lasting effects. However, the metabolic role of the porcine core microbiota, especially in relation to the rest of the microbial community, is currently missing. We present here the first dynamic model of the porcine core microbiota, which we used to estimate the core-microbiota metabolite production and to forecast the effect of a synbiotic intervention targeting the core genera of the core microbiota. We developed a community model in which a total of 17 microbial groups were established based on culture-based information of representative species. First, the model parameters were estimated, and the resulting model simulations were compared favorably with in vitro experimentation. The model was then used to predict the microbial dynamics of the core and non-core members under different experimental conditions. Therefore, it was able to theorize the main-metabolite core microbiota contribution, hypothesizing that it could be mainly responsible for acetate and propionate, but not for butyrate production.IMPORTANCECurrently, little information is present in the literature to describe the generic metabolic role of the porcine core microbiota or to inform on the effect of interventions targeting the core genera. Moreover, both in vitro and in vivo experimentations aiming to explore the core microbiota dynamics are technically demanding, expensive, or restricted by ethical considerations. Modeling approaches can be used as an initial exploratory tool to develop hypotheses for targeted experimentation. Our mathematical model provides initial information on the microbial and metabolite dynamics of the core microbiota in relation to diet and therapeutic intervention.

Presence of digestible starch impacts in vitro fermentation of resistant starch

Starch is an important energy source for humans. Starch escaping digestion in the small intestine will transit to the colon to be fermented by gut microbes. Many gut microbes express α-amylases that can degrade soluble starch, but only a few are able to degrade intrinsic resistant starch (RS), which is insoluble and highly resistant to digestion (≥80% RS). We studied the in vitro fermentability of eight retrograded starches (RS-3 preparations) differing in rapidly digestible starch content (≥70%, 35-50%, ≤15%) by a pooled adult faecal inoculum and found that fermentability depends on the digestible starch fraction. Digestible starch was readily fermented yielding acetate and lactate, whereas resistant starch was fermented much slower generating acetate and butyrate. Primarily Bifidobacterium increased in relative abundance upon digestible starch fermentation, whereas resistant starch fermentation also increased relative abundance of Ruminococcus and Lachnospiraceae. The presence of small fractions of total digestible starch (±25%) within RS-3 preparations influenced the fermentation rate and microbiota composition, after which the resistant starch fraction was hardly fermented. By short-chain fatty acid quantification, we observed that six individual faecal inocula obtained from infants and adults were able to ferment digestible starch, whereas only one adult faecal inoculum was fermenting intrinsic RS-3. This suggests that, in contrast to digestible starch, intrinsic RS-3 is only fermentable when specific microbes are present. Our data illustrates that awareness is required for the presence of digestible starch during in vitro fermentation of resistant starch, since such digestible fraction might influence and overrule the evalution of the prebiotic potential of resistant starches.

Characterization and the cholesterol-lowering effect of dietary fiber from fermented black rice (Oryza sativa L.)

Black rice was fermented with Neurospora crassa, after which the dietary fiber (DF) extracted from it was characterized and evaluated for its cholesterol-lowering effect in mice. The findings demonstrated that fermentation increased the level of soluble DF from 17.27% ± 0.12 to 29.69% ± 0.26 and increased the adsorption capacity of DF for water, oil, cholesterol, glucose and sodium cholate. The fermented DF had a more loose and porous structure than that extracted from unfermented rice. Additionally, feeding with DF from the fermented black rice significantly reduced body weight, lowered total cholesterol levels and improved the lipid profile in mice gavaged with a high dose (5 g per kg bw) or a low dose (2.5 g per kg·bw). ELISA showed that the hepatic expression of typical proteins and enzymes that are involved in cholesterol metabolism was regulated by the fermented rice DF, leading to reduced cholesterol production and increased cholesterol clearance. The fermented DF also modified the gut microbiota composition (e.g. Firmicutes reduced and Akkermansia increased), which promoted the production of short-chain fatty acids. In conclusion, fermentation can modify the structure and function of DF in black rice and the fermented dietary fiber has excellent cholesterol lowering effects possibly by cholesterol adsorption, cholesterol metabolism modulation, and intestinal microflora regulation.

The functional implications of high-amylose wholegrain wheat flours: An in vitro digestion and fermentation approach combined with metabolomics

Wheat flour is one of the most prevalent foodstuffs for human consumption, and novel strategies are underway to enhance its nutritional properties. This work evaluated wholegrain flours from bread wheat lines with different amylose/amylopectin ratios through in vitro starch digestion and large intestine fermentation. High-amylose flours presented a higher resistant starch content and lower starch hydrolysis index. Moreover, UHPLC-HRMS metabolomics was carried out to determine the profile of the resulting in vitro fermentates. The multivariate analysis highlighted distinctive profiles between the flours derived from the different lines compared to the wild type. Peptides, glycerophospholipids, polyphenols, and terpenoids were identified as the main markers of the discrimination. The high-amylose flour fermentates showed the richest bioactive profile, containing stilbenes, carotenoids, and saponins. Present findings pave the way toward applying high-amylose flours to design novel functional foods.

Effect of resistant starch types as a prebiotic

Since the role of intestinal microbiota in metabolism was understood, the importance of dietary components such as fibres and prebiotics, which affect the modulation of microbiota, has been increasing day by day. While all prebiotic components are considered dietary fibre, not every dietary fibre is considered a prebiotic. While fructooligosaccharides, galactooligosaccharides, inulin, and galactans are considered prebiotics, other fermentable carbohydrates are considered candidate prebiotic components based on in vitro and preclinical studies. Resistant starch, one of such carbohydrates, is considered a potential prebiotic component when it is made resistant to digestion naturally or chemically. In this review, both in vitro and in vivo studies in which the prebiotic capacity of type II, type III, and type IV resistant starch isolated from food and produced commercially was assessed were analyzed. According to the results of current studies, certain types of resistant starch are thought to have a high prebiotic capacity, and they may be candidate prebiotic components although positive results have not been achieved in all studies. KEY POINTS: • Resistant starch is undigested in the small intestine and is fermented in the large intestine. • Resistant starch fermentation positively affects the growth of Bifidobacterium and Lactobacillus. • Resistant starch can be considered a prebiotic ingredient.

Effect of Fiber Fermentation and Protein Digestion Kinetics on Mineral Digestion in Pigs

Nutrient kinetic data and the timing of nutrient release along the gastrointestinal tract (GIT), are not yet widely used in current feed formulations for pigs and poultry. The present review focuses on interactions between fermentable substrates (e.g., starch, fiber, and protein) and selected minerals on nutrient digestion and absorption to determine nutritional solutions to maximize animal performance, principally in the grower–finisher phase, with the aim of minimizing environmental pollution. For phosphorus (P), myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6), copper (Cu), and zinc (Zn), no standardized methodologies to assess in vitro mineral digestion exist. The stepwise degradation of InsP6 to lower inositol phosphate (InsP) forms in the GIT is rare, and inositol phosphate4 (InsP4) might be the limiting isomer of InsP degradation in diets with exogenous phytase. Furthermore, dietary coefficients of standardized total tract digestibility (CSTTD) of P might be underestimated in diets with fermentable ingredients because of increased diet-specific endogenous P losses (EPL), and further clarification is required to better calculate the coefficients of true total tract digestibility (CTTTD) of P. The quantification of fiber type, composition of fiber fractions, their influence on digestion kinetics, effects on digesta pH, and nutrient solubility related to fermentation should be considered for formulating diets. In conclusion, applications of nutrient kinetic data should be considered to help enhance nutrient digestion and absorption in the GIT, thereby reducing nutrient excretion.

Starchy and fibrous feedstuffs differ in their in vitro digestibility and fermentation characteristics and differently modulate gut microbiota of swine

Background

Alternative feedstuffs may contribute to reducing feed costs of pig production. But these feedstuffs are typically rich in fiber and resistant starch (RS). Dietary fibers and RS are fermented in the gastrointestinal tract (GIT) and modulate the microbial community. Certain microbes in the GIT can promote host health, depending on the type of fermentation substrates available. In this study, six alternative feedstuffs (three starchy: Okinawan sweet potato, OSP; yam, and taro, and three fibrous: wheat millrun, WMR; barley brewers grain, BBG; and macadamia nut cake, MNC) were evaluated for their in vitro digestibility and fermentation characteristics and their effects on pig’s hindgut microbial profile. After 2 steps of enzymatic digestion assay, residues were fermented using fresh pig feces as microbial inoculum, and gas production was recorded periodically for 72 h and modeled for fermentation kinetics. After fermentation, the residual liquid phase was analyzed for short-chain fatty acid (SCFA), and the solid phase was used to determine the nutrient’s digestibility and microbial community.

Results

In vitro ileal digestibility of dry matter and gross energy was higher in starchy than fibrous feedstuffs. Total gas and SCFA production were significantly higher (P < 0.001) in starchy feedstuffs than fibrous feedstuffs. Both acetate and propionate production was significantly higher (P < 0.001) in all starchy feedstuffs than BBG and MNC; WMR was in between. Overall alpha diversity was not significantly different within and between starchy and fibrous feedstuffs. Beta diversity (measured using bray Curtis dissimilarity distance) of starchy feedstuffs was significantly different (P < 0.005) than fibrous feedstuffs.

Conclusion

Starchy feedstuffs acted as a substrate to similar types of microbes, whereas fibrous feedstuffs resulted in a more diverse microbial population. Such alternative feedstuffs may exert comparable beneficial effects, thus may be included in swine diets to improve gut health.

Effects of Selenium Auricularia cornea Culture Supplementation on Growth Performance, Antioxidant Status, Tissue Selenium Concentration and Meat Quality in Growing-Finishing Pigs

Simple Summary

Selenium Auricularia cornea culture (SAC) is a dried product via full fermentation, containing organic-Se, Auricularia cornea (AC) mycelium, and various metabolites of AC. The objective of this study was to evaluate whether SAC could effectively improve the health, growth, meat quality, and oxidative stability of meat in growing-finishing pigs. Currently, dietary SAC supplementation positively impacts growth performance and oxidative stability of fresh meat.

Abstract

Selenium Auricularia cornea culture (SAC) is a new source of organic selenium. Two experiments were conducted to determine the available energy of SAC fed to pigs and to evaluate the effects of dietary SAC supplementation on growth performance, serum biochemical profiles, fecal short chain fatty acids (SCFA), meat quality, tissue selenium concentration, and oxidative stability of fresh meat in growing-finishing pigs. In Experiment (Exp.) 1, 12 barrows with average body weight (BW) of 42.40 ± 5.30 kg were randomly allotted to two groups and fed the basal diet and SAC-supplemented diet, individually. In Exp. 2, 96 growing-finishing pigs (BW: 91.96 ± 7.55 kg) were grouped into four dietary treatments; each treatment contained six replicates with four pigs per replicate. The four treatments fed a control diet and three experimental diets supplemented with 0.6%, 1.2%, and 2.4% SAC, respectively. The trial lasted for 45 days. The results revealed that digestible energy (DE) of SAC was 11.21 MJ/kg. The average daily gain (ADG) was improved in pigs fed 1.2% and 2.4% SAC during day 24 to 45 and the overall period. Dietary 1.2% and 2.4% SAC supplementation had a lower F/G (p < 0.05) than the control diet during different stages. Dietary SAC supplementation increased fecal butyrate contents (p < 0.05), and pigs fed 1.2% and 2.4% SAC diets had a higher MCT1 mRNA expression (p = 0.04) in the colon. Pigs fed 2.4% SAC had higher GSH-Px contents (p < 0.05) in serum, liver, and longissimus dorsi muscle (LDM) than those in the control group. The 2.4% SAC-supplemented group revealed a higher Se content (p < 0.05) in LDM and a lower MDA concentration (p < 0.05) in fresh meat during the simulated retail display on day six. In conclusion, this study suggested that SAC was more effective in improving growth, enhancing the antioxidant status, depositing Se in muscle, and increasing meat oxidative stability of pigs.

Temperature Profile in Starch during Irradiation. Indirect Effects in Starch by Radiation-Induced Heating

Present research deals with exposure of granular starch to the accelerated electron of 5.5 MeV energy in order to examine: (i) the temperature evolution in starch within an irradiation process and (ii) the indirect effects generated in starch by radiation-induced heating. The temperature evolution in potato and corn starches within the irradiation process was investigated by placing two different sensors inside each starch batch and recording the temperature simultaneously. Each starch batch was sampled into distinct location sectors of different absorbed radiation levels. The output effects in each sample were analyzed through physicochemical properties such as moisture content, acidity and color attributes. The outcomes showed that a starch temperature profile had different major stages: (i) heating during irradiation, (ii) post-irradiation heating, up to the maximum temperature is reached, and (iii) cooling to the room temperature. A material constant with signification of a relaxation time was identified by modeling the temperature evolution. Changes of the investigated properties were induced both by irradiation and radiation-induced heating, depending on the starch type and the batch sectors. Changes in the irradiated batch sectors were explained by irradiation and radiation-induced heating whereas changes in the sector of non-irradiated starch were attributed only to the heating.

In vitro evaluation of fermentation characteristics of type 3 resistant starch

Four different resistant starch (RS) type 3 (RS3; retrograded starch) and a RS type 2 (RS2; native high amylose maize starch) were in vitro digested and fermented by faecal inoculum. Total and individual short chain fatty acid (SCFA) production and associated kinetic parameters were assessed up to 20 h of in vitro fermentation. Total SCFA production was different (p < 0.05) among RS-rich ingredients, ranging from 7.43 to 8.72 mmol/g dry starch incubated. Differences (p < 0.05) were recorded for propionate and butyrate productions. Different (p < 0.05) half-time of total SCFA fermentation (T_1/2), maximum rate of production (R_max) and the time of occurrence (T_max) values were measured among RS-rich ingredients, ranging from 3.3 to 5.6 h, from 1.06 to 1.85 mmol/g dry starch incubated per hour and from 2.6 to 4.9 h, respectively. Similar trends were measured considering the fermentative kinetics of individual SCFA. Present preliminary in vitro findings indicated that quantitative and qualitative production of SCFA, and inherent fermentation kinetics, were influenced by the type of RS. These findings are based on an in vitro approach, thus requiring in vivo trials.

Colonic fermentation of water soluble fiber fraction extracted from sugarcane (Sacchurum officinarum L.) bagasse in murine models

Biochemical effects of the water soluble fiber fraction of sugarcane bagasse (BSF) fermented in the colon was examined to evaluate its potential health promoting effects. A feeding experiment involving Fischer 344 rats, was conducted with 3 experimental diets containing, cellulose (CON), a commercial xylo-oligosaccharide (XYO) and BSF (BGS). Cumulative feed intake was significantly lower in XYO group while cecal weight was significantly higher. Acetic and propionic acid contents in the cecal content were significantly higher in the BGS and XYO, respectively. Total short chain fatty acid content was significantly higher in BGS and XYO resulting significantly lower cecal pH. Beneficial bacteria such as Bifidobacterium, Blautia, Akkermansia and Roseburia abundance was significantly higher in the XYO and BGS groups. Further, mucin and immunoglobulin-A contents were significantly higher in BGS group compared to CON group. Thus, BSF exhibited its ability to enhance the intestinal and systemic health upon fermentation in the colon.

Structural Changes of Starch-Lipid Complexes during Postprocessing and Their Effect on In Vitro Enzymatic Digestibility

The effects of cooking and storage on the structure and in vitro enzymatic digestibility of complexes formed between fatty acids and debranched high-amylose starch (DHA7-FA) were investigated for the first time. Cooking greatly decreased the crystallinities of DHA7-lauric acid (LA) and DHA7-myristic acid (MA) complexes but had little effect on the crystallinities of DHA7-palmitic acid (PA) and DHA7-stearic acid (SA) complexes. Cooking increased the enthalpy-change (Δ H) values and short-range molecular orders of DHA7-FA complexes. Cooking decreased the in vitro enzymatic digestibility of DHA7-FA complexes, with the extent of the effect decreasing with increasing fatty acid chain length. Holding the samples at 4 °C for 24 h after cooking did not greatly affect the long- and short-range molecular orders nor the in vitro enzymatic digestibility of DHA7-FA complexes. From this study, we conclude that cooking disrupted the long-range crystalline structures of DHA7-LA and DHA7-MA complexes but enhanced the short-range molecular orders of all of the DHA7-FA complexes. The latter effect accounted mainly for the reduced in vitro enzymatic digestibility of DHA7-FA complexes.

Edible nuts deliver polyphenols and their transformation products to the large intestine: An in vitro fermentation model combining targeted/untargeted metabolomics

The fate of polyphenols from edible tree nuts was investigated using a simulated in vitro intestinal fermentation system. The digested food matrix was fermented for 48 h and the changes in the phenolic profiles were evaluated by both untargeted UHPLC-QTOF and targeted UHPLC-Orbitrap mass spectrometry. The untargeted metabolomics approach allowed us to monitor the comprehensive changes in phenolic profiles from 0 up to 48 h of in vitro fermentation. Multivariate statistics (i.e., orthogonal projection to latent structures discriminant analysis) applied to this untargeted data allowed us to identify the most discriminating phenolic metabolites and to further understand the colonic transformation pathways involved. In particular, 13 putatively identified compounds derived from flavonoids, lignans and phenolic acids were found to have the highest discrimination potential. Six phenolic metabolites were then quantified by means of targeted metabolomics (using a UHPLC-Orbitrap). These metabolites included 3,4-dihydroxyphenylacetic acid, 4-hydroxybenzoic acid, hippuric acid, caffeic acid, protocatechuic acid and protocatechuic aldehyde. Using the targeted data, a clear matrix effect was observed over time, with an increase of some phenolic metabolites moving from 8 to 48 h of in vitro fermentation. Based on these data, catabolic pathways for colonic microbial degradation of flavonoids, hydroxycinnamic acids, tyrosols and lignans are proposed. Our findings show that edible tree nuts deliver polyphenols to the colon, where several microbial transformations occur that lead to smaller phenolic metabolites being observed. Furthermore, we found that the combined use of targeted and untargeted metabolomics can be particularly effective for investigating the fate of polyphenols in the large intestine.

Feeding sows resistant starch during gestation and lactation impacts their faecal microbiota and milk composition but shows limited effects on their progeny

Background

Establishment of a beneficial microbiota profile for piglets as early in life as possible is important as it will impact their future health. In the current study, we hypothesized that resistant starch (RS) provided in the maternal diet during gestation and lactation will be fermented in their hindgut, which would favourably modify their milk and/or gut microbiota composition and that it would in turn affect piglets’ microbiota profile and their absorptive and immune abilities.

Methods

In this experiment, 33% of pea starch was used in the diet of gestating and lactating sows and compared to control sows. Their faecal microbiota and milk composition were determined and the colonic microbiota, short-chain fatty acids (SCFA) production and gut health related parameters of the piglets were measured two days before weaning. In addition, their overall performances and post-weaning faecal score were also assessed.

Results

The RS diet modulated the faecal microbiota of the sows during gestation, increasing the Firmicutes:Bacteroidetes ratio and the relative abundance of beneficial genera like Bifidobacterium but these differences disappeared during lactation and maternal diets did not impact the colonic microbiota of their progeny. Milk protein concentration decreased with RS diet and lactose concentration increased within the first weeks of lactation while decreased the week before weaning with the RS diet. No effect of the dietary treatment, on piglets’ bodyweight or diarrhoea frequency post-weaning was observed. Moreover, the intestinal morphology measured as villus height and crypt depths, and the inflammatory cytokines in the intestine of the piglets were not differentially expressed between maternal treatments. Only zonula occludens 1 (ZO-1) was more expressed in the ileum of piglets born from RS sows, suggesting a better closure of the mucosa tight junctions.

Conclusion

Changes in the microbiota transferred from mother to piglets due to the inclusion of RS in the maternal diet are rather limited even though milk composition was affected.

In Vivo Assessment of Resistant Starch Degradation by the Caecal Microbiota of Mice Using RNA-Based Stable Isotope Probing-A Proof-of-Principle Study

Resistant starch (RS) is the digestion resistant fraction of complex polysaccharide starch. By reaching the large bowel, RS can function as a prebiotic carbohydrate, i.e., it can shape the structure and activity of bowel bacterial communities towards a profile that confers health benefits. However, knowledge about the fate of RS in complex intestinal communities and the microbial members involved in its degradation is limited. In this study, 16S ribosomal RNA (rRNA)-based stable isotope probing (RNA-SIP) was used to identify mouse bowel bacteria involved in the assimilation of RS or its derivatives directly in their natural gut habitat. Stable-isotope [U¹³C]-labeled native potato starch was administrated to mice, and caecal contents were collected before 0 h and 2 h and 4 h after administration. 'Heavy', isotope-labeled [¹³C]RNA species, presumably derived from bacteria that have metabolized the labeled starch, were separated from 'light', unlabeled [¹²C]RNA species by fractionation of isolated total RNA in isopycnic-density gradients. Inspection of different density gradients showed a continuous increase in 'heavy' 16S rRNA in caecal samples over the course of the experiment. Sequencing analyses of unlabeled and labeled 16S amplicons particularly suggested a group of unclassified Clostridiales, Dorea, and a few other taxa (Bacteroides, Turicibacter) to be most actively involved in starch assimilation in vivo. In addition, metabolic product analyses revealed that the predominant ¹³C-labeled short chain fatty acid (SCFA) in caecal contents produced from the [U¹³C] starch was butyrate. For the first time, this study provides insights into the metabolic transformation of RS by intestinal bacterial communities directly within a gut ecosystem, which will finally help to better understand its prebiotic potential and possible applications in human health.

Diets high in resistant starch and arabinoxylan modulate digestion processes and SCFA pool size in the large intestine and faecal microbial composition in pigs

The effects of a high level of dietary fibre (DF) either as arabinoxylan (AX) or resistant starch (RS) on digestion processes, SCFA concentration and pool size in various intestinal segments and on the microbial composition in the faeces were studied in a model experiment with pigs. A total of thirty female pigs (body weight 63.1 (sem 4.4) kg) were fed a low-DF, high-fat Western-style control diet (WSD), an AX-rich diet (AXD) or a RS-rich diet (RSD) for 3 weeks. Diet significantly affected the digestibility of DM, protein, fat, NSP and NSP components, and the arabinose:xylose ratio, as well as the disappearance of NSP and AX in the large intestine. RS was mainly digested in the caecum. AX was digested at a slower rate than RS. The digesta from AXD-fed pigs passed from the ileum to the distal colon more than twice as fast as those from WSD-fed pigs, with those from RSD-fed pigs being intermediate (P< 0.001). AXD feeding resulted in a higher number of Faecalibacterium prausnitzii, Roseburia intestinalis, Blautia coccoides-Eubacterium rectale, Bifidobacterium spp. and Lactobacillus spp. in the faeces sampled at week 3 of the experimental period (P< 0.05). In the caecum, proximal and mid colon, AXD feeding resulted in a 3- to 5-fold higher pool size of butyrate compared with WSD feeding, with the RSD being intermediate (P <0.001). In conclusion, the RSD and AXD differently affected digestion processes compared with the WSD, and the AXD most efficiently shifted the microbial composition towards butyrogenic species in the faeces and increased the large-intestinal butyrate pool size.

Fermentable non-starch polysaccharides increases the abundance of Bacteroides-Prevotella-Porphyromonas in ileal microbial community of growing pigs

Most plant-origin fiber sources used in pig production contains a mixture of soluble and insoluble non-starch polysaccharides (NSP). The knowledge about effects of these sources of NSP on the gut microbiota and its fermentation products is still scarce. The aim of this study was to investigate effects of feeding diets with native sources of NSP on the ileal and fecal microbial composition and the dietary impact on the concentration of short-chain fatty acids (SCFA) and lactic acid. The experiment comprised four diets and four periods in a change-over design with seven post valve t-cecum cannulated growing pigs. The four diets were balanced to be similar in NSP content and included one of four fiber sources, two diets were rich in pectins, through inclusion of chicory forage (CFO) and sugar beet pulp, and two were rich in arabinoxylan, through inclusion of wheat bran (WB) and grass meal. The gut microbial composition was assessed with terminal restriction fragment (TRF) length polymorphism and the abundance of Lactobacillus spp., Enterobacteriaceae, Bacteroides-Prevotella-Porphyromonas and the β-xylosidase gene, xynB, were assessed with quantitative PCR. The gut microbiota did not cluster based on NSP structure (arabinoxylan or pectin) rather, the effect was to a high degree ingredient specific. In pigs fed diet CFO, three TRFs related to Prevotellaceae together consisted of more than 25% of the fecal microbiota, which is about 3 to 23 times higher (P<0.05) than in pigs fed the other diets. Whereas pigs fed diet WB had about 2 to 22 times higher abundance (P<0.05) of Megasphaera elsdenii in feces and about six times higher abundance (P<0.05) of Lactobacillus reuteri in ileal digesta than pigs fed the other diets. The total amount of digested NSP (r=0.57; P=0.002), xylose (r=0.53; P=0.004) and dietary fiber (r=0.60; P=0.001) in ileal digesta were positively correlated with an increased abundance of Bacteroides-Prevotella-Porphyromonas. The effect on SCFA was correlated to specific neutral sugars where xylose increased the ileal butyric acid proportion, whereas arabinose increased the fecal butyric acid proportion. Moreover, chicory pectin increased the acetic acid proportion in both ileal digesta and feces.