High Amylose Starch with Low In Vitro Digestibility Stimulates Hindgut Fermentation and Has a Bifidogenic Effect in Weaned Pigs

The Influence of Increasing Roughage Content in the Diet on the Growth Performance and Intestinal Flora of Jinwu and Duroc × Landrace × Yorkshire Pigs

The Jinwu pig (JW) is a hybrid breed originating from the Chinese indigenous Jinhua pig and Duroc pig, boasting excellent meat quality and fast growth rates. This study aimed to verify the tolerance of JW to roughage, similar to most Chinese indigenous pigs. In this research, two types of feed were provided to JW and Duroc × Landrace × Yorkshire pigs (DLY): a basal diet and a roughage diet (increasing the rice bran and wheat bran content in the basal diet from 23% to 40%) for a 65-day experimental period. The roughage diet showed an increasing trend in the feed conversion ratio (F/G), with a 17.61% increase in feed consumption per unit weight gain for DLY, while the increase for JW was only 4.26%. A 16S rRNA sequencing analysis revealed that the roughage diet increased the relative abundance of beneficial bacteria, such as Lactobacillus and Clostridium, while reducing the relative abundance of some potential pathogens, thus improving the gut microbiota environment. After being fed with the roughage diet, the abundance of bacterial genera, such as Treponema, Terrisporobacter, Coprococcus, and Ruminococcaceae, which aid in the digestion and utilization of dietary fiber, were significantly higher in Jinwu compared to DLY, indicating that these bacterial genera confer Jinwu with a higher tolerance to roughage than DLY.

Effects of different starch structures on energy metabolism in pigs

BACKGROUND

Starch is a major component of carbohydrates and a major energy source for monogastric animals. Starch is composed of amylose and amylopectin and has different physiological functions due to its different structure. It has been shown that the energy supply efficiency of amylose is lower than that of amylopectin. However, there are few studies on the effect of starch structure on the available energy of pigs. The purpose of this study was to measure the effect of different structures of starch in the diet on the net energy (NE) of pigs using a comparative slaughter method and to establish a prediction equation to estimate the NE of starch with different structures. Fifty-six barrows (initial BW 10.18 ± 0.11 kg) were used, and they were housed and fed individually. Pigs were divided into 7 treatments, with 8 replicates for each treatment and 1 pig for each replicate. One of the treatments was randomly selected as the initial slaughter group (ISG). Pigs in the remaining treatments were assigned to 6 diets, fed with basic diet and semi-pure diets with amylose/amylopectin ratio (AR) of 3.09, 1.47, 0.25, 0.15 and 0.12, respectively. The experiment lasted for 28 d.

RESULTS

Results showed that compared with the high amylose (AM) groups (AR 3.09 and 1.47), the high amylopectin (AP) group (AR 0.15) significantly increased the final BW, average daily weight gain and average daily feed intake of pigs (P < 0.05), but the F:G of the AM group was lower (P < 0.01). In addition, AR 0.15 and 0.12 groups have higher (P < 0.01) nutrient digestibility of dry matter, crude protein, gross energy and crude ash. Meanwhile, compared with other groups, AR 0.15 group has a higher (P < 0.05) NE intake and energy retention (RE). The regressive equation for predicting with starch structures was established as RE = 1,235.243 - 48.298AM/AP (R2 = 0.657, P = 0.05).

CONCLUSIONS

In conclusion, NE intake and RE of pigs augmented with the increase of dietary amylopectin content, indicating that diets high in amylopectin were more conducive to promoting the growth of pigs in the late conservation period.

Review: Nutrient and energy supply in monogastric food producing animals with reduced environmental and climatic footprint and improved gut health

With more efficient utilisation of dietary nutrients and energy, diversified production systems, modifications of diet composition with respect to feedstuffs included and the use of free amino acids, the negative impact of animal food production on the environment and climate can be reduced. Accurate requirements for nutrients and energy for animals with differing physiological needs, and the use of robust and accurate feed evaluation systems are key for more efficient feed utilisation. Data on CP and amino acid requirements in pigs and poultry indicate that it should be possible to implement indispensable amino acid-balanced diets with low- or reduced-protein content without any reduction in animal performance. Potential feed resources, not competing with human food security, can be derived from the traditional food- and agroindustry, such as various waste streams and co-products of different origins. In addition, novel feedstuffs emerging from aquaculture, biotechnology and innovative new technologies may have potential to provide the lack of indispensable amino acids in organic animal food production. High fibre content is a nutritional limitation of using waste streams and co-products as feed for monogastric animals as it is associated with decreased nutrient digestibility and reduced dietary energy values. However, minimum levels of dietary fibre are needed to maintain the normal physiological function of the gastro-intestinal tract. Moreover, there may be positive effects of fibre in the diet such as improved gut health, increased satiety, and an overall improvement of behaviour and well-being.

Characterization of the Glucan-Branching Enzyme GlgB Gene from Swine Intestinal Bacteria

Starch hydrolysis by gut microbiota involves a diverse range of different enzymatic activities. Glucan-branching enzyme GlgB was identified as the most abundant glycosidase in Firmicutes in the swine intestine. GlgB converts α-(1→4)-linked amylose to form α-(1→4,6) branching points. This study aimed to characterize GlgB cloned from a swine intestinal metagenome and to investigate its potential role in formation of α-(1→4,6)-branched α-glucans from starch. The branching activity of purified GlgB was determined with six different starches and pure amylose by quantification of amylose after treatment. GlgB reduced the amylose content of all 6 starches and amylose by more than 85% and displayed a higher preference towards amylose. The observed activity on raw starch indicated a potential role in the primary starch degradation in the large intestine as an enzyme that solubilizes amylose. The oligosaccharide profile showed an increased concentration of oligosaccharide introduced by GlgB that is not hydrolyzed by intestinal enzymes. This corresponded to a reduced in vitro starch digestibility when compared to untreated starch. The study improves our understanding of colonic starch fermentation and may allow starch conversion to produce food products with reduced digestibility and improved quality.

Dual Regulation of Sulfonated Lignin to Prevent and Treat Type 2 Diabetes Mellitus

With the rapid increase of diabetes cases in the world, there is an increasing demand for slowing down and managing diabetes and its effects. It is considered that a viable prophylactic treatment for type 2 diabetes mellitus (T2DM) is to reduce carbohydrate digestibility by controlling the activities of α-amylase and α-glucosidase to control postprandial hyperglycemia and promote the growth of intestinal beneficial bacteria. In this work, the effects of sulfonated lignin with different sulfonation degrees (0.8 mmol/g, SL₁; 2.9 mmol/g, SL₂) on the inhibition of α-amylase and α-glucosidase and the proliferation of intestinal beneficial bacteria in vitro were investigated. The results showed that both SL₁ and SL₂ can inhibit the activity of α-amylase and α-glucosidase. The inhibition capacity (IC₅₀, 32.35 μg/mL) of SL₂ with a low concentration (0-0.5 mg/mL) to α-amylase was close to that of acarbose to α-amylase (IC₅₀, 27.33 μg/mL). Compared with the control groups, the bacterial cell concentrations of Bifidobacteria adolescentis and Lactobacillus acidophilus cultured with SL₁ and SL₂ increased in varying degrees (8-36%), and the produced short-chain fatty acids were about 1.2 times higher. This work demonstrates the prospect of sulfonated lignin as a prebiotic for the prevention and treatment of T2DM, which provides new insights for opening up a brand new field of lignin.

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.

Prebiotics and β-Glucan as gut modifier feed additives in modulation of growth performance, protein utilization status and dry matter and lactose digestibility in weanling pigs

There are growing interests in developing novel gut modifier feed additives and alternative therapeutics to replace antimicrobials to enhance efficiency of nutrient utilization and to address the antimicrobial resistance threat to public health facing the global pork production. Biological mechanisms of supplementing lactose for enhancing weanling pig growth and nitrogen utilization are unclear. Thus, this study was prompted to determine effects of dietary supplementation of 3 prebiotics and oat β-glucan vs. a sub-therapeutic antibiotic on growth performance, whole-body protein utilization status, the apparent total tract dry matter (DM) and lactose digestibility in weanling pigs fed corn and soybean meal (SBM)-based diets. Six experimental diets were formulated with corn (40%), SBM (28%) and supplemented with dried whey powder (20%) and fish meal (9%) with titanium oxide (0.30%) as the digestibility marker. Diet 1 (NC, negative control), as the basal diet, contained no antibiotics and no supplemental prebiotics or β-glucan. Diet 2 (PC, positive control), contained an antibiotic premix (Lincomix-44 at 0.10%) in the basal diet at the expense of cornstarch. Diets 3, 5 and 6 contained 0.75% of the three test prebiotics of retrograded cornstarch (Diet 3), Fibersol-2 (Diet 5, a modified digestion-resistant maltodextrin) and inulin (Diet 6), and the viscous soluble fiber oat β-glucan (Diet 4), respectively, at the expense of cornstarch. A total of 144 Yorkshire pigs, at the age of 21 days (d) and an average body weight (BW) of 5.5 kg, were allocated to 12 floor pens with 3 barrows and 3 gilts per pen, and fed one of the 6 diets for 21 d in 2 study blocks according to a completely randomized block design. Initial and final pig BW, average daily gain (ADG), average daily feed intake (ADFI), representative pig plasma urea concentration as well as the apparent total tract DM and lactose digestibility during d 8-15 were measured. Analyses of variances, Dunnett’s and Tukey’s tests were conducted on the endpoints by using the SAS mixed model. There were no differences (P &gt; 0.05) in ADG, ADFI, feed to gain ratio, plasma urea concentration, the apparent total tract apparent DM and lactose digestibility and the predicted whole-gut lactase digestive capacity among the diets, as examined by the Tukey’s test. There were no differences (P &gt; 0.05) in these endpoints between each of the four treatment diets and the NC or the PC diet as examined by the Dunnett’s test. The total tract lactose digestibility was determined to be at 100%. The predicted whole-gut lactase digestive capacity was about eight times of the daily lactose intake when dietary lactose contents were supplemented at 10 - 12% (as-fed basis). In conclusion, dietary supplementation (at 0.75%) of the prebiotics and the oat β-glucan did not significantly affect the major growth performance endpoints, whole-body protein utilization status as well as the apparent total tract DM and lactose digestibility in the weanling pigs fed the corn and SBM-based diets. The promoting effect for growth and nitrogen utilization associated with dietary supplementation of lactose is due to the fact that lactose is a completely and rapidly digestible sugar rather than acting as an effective prebiotic in weanling pig nutrition.

High-Amylose Corn Starch Regulated Gut Microbiota and Serum Bile Acids in High-Fat Diet-Induced Obese Mice

Simple Summary

High-amylose corn starch, as a kind of resistant starch, could profoundly regulate the gut microbiota and exert anti-obesity properties. Since the gut microbiota was found to improve metabolic health by altering circulating bile acids, therefore, here we investigated the association between the gut microbiota and serum bile acids in high fat diet induced obese mice fed with high-amylose corn starch. We found high-amylose corn starch could modulate the gut microbiota composition and partially restore the alternations in circulating bile acid profiles in obese mice. These influences on gut microbiota and circulating bile acids could be the underlying mechanisms of anti-obesity activity of high-amylose corn starch.

Abstract

High-amylose corn starch is well known for its anti-obesity activity, which is mainly based on the regulatory effects on gut microbiota. Recently, the gut microbiota has been reported to improve metabolic health by altering circulating bile acids. Therefore, in this study, the influence of high-amylose corn starch (HACS) on intestinal microbiota composition and serum bile acids was explored in mice fed with a high fat diet (HFD). The results demonstrated HACS treatment reduced HFD-induced body weight gain, hepatic lipid accumulation, and adipocyte hypertrophy as well as improved blood lipid profiles. Moreover, HACS also greatly impacted the gut microbiota with increased Firmicutes and decreased Bacteroidetes relative abundance being observed. Furthermore, compared to ND-fed mice, the mice with HFD feeding exhibited more obvious changes in serum bile acids profiles than the HFD-fed mice with the HACS intervention, showing HACS might restore HFD-induced alterations to bile acid composition in blood. In summary, our results suggested that the underlying mechanisms of anti-obesity activity of HACS may involve its regulatory effects on gut microbiota and circulating bile acids.

Dietary Amylose/Amylopectin Ratio Modulates Cecal Microbiota and Metabolites in Weaned Goats

Increasing the ratio of amylose in the diet can increase the quantity of starch that flows to the large intestine for microbial fermentation. This leads to the alteration of microbiota and metabolite of the hindgut, where the underlying mechanism is not clearly understood. The present study used a combination of 16S amplicon sequencing technology and metabolomics technique to reveal the effects of increasing ratios of amylose/amylopectin on cecal mucosa- and digesta-associated microbiota and their metabolites in young goats. Twenty-seven Xiangdong black female goats with average body weights (9.00 ± 1.12 kg) were used in this study. The goats were randomly allocated to one of the three diets containing starch with 0% amylose corn (T1), 50% high amylose corn (T2), and 100% high amylose corn (T3) for 35 days. Results showed that cecal valerate concentration was higher (P < 0.05) in the T2 group than those in the T1 and T3 groups. The levels of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were decreased (P < 0.05) in cecal tissue while IL-10 was increased (P < 0.05) in the T2 group when compared with T1 or T3 groups. At the phylum level, the proportion of mucosa-associated Spirochaetes was increased (P < 0.05), while Proteobacteria was deceased by feeding high amylose ratios (P < 0.05). The abundance of Verrucomicrobia was decreased (P < 0.05) in the T3 group compared with the T1 and T2 groups. The abundance of digesta-associated Firmicutes was increased (P < 0.05) while Verrucomicrobia and Tenericutes were deceased (P < 0.05) with the increment of amylose/amylopectin ratios. The LEfSe analysis showed that a diet with 50% high amylose enriched the abundance of beneficial bacteria such as Faecalibacterium and Lactobacillus in the digesta and Akkermansia in the mucosa compared with the T1 diet. The metabolomics results revealed that feeding a diet containing 50% high amylose decreased the concentration of fatty acyls-related metabolites, including dodecanedioic acid, heptadecanoic acid, and stearidonic acid ethyl ester compared with the T1 diet. The results suggested that a diet consisting of 50% high amylose could maintain a better cecal microbiota composition and host immune function.

Resistant starch: Implications of dietary inclusion on gut health and growth in pigs: a review

Starch from cereal grains, pulse grains, and tubers is a major energy substrate in swine rations constituting up to 55% of the diet. In pigs, starch digestion is initiated by salivary and then pancreatic α-amylase, and has as final step the digestion of disaccharides by the brush-border enzymes in the small intestine that produce monosaccharides (glucose) for absorption. Resistant starch (RS) is the proportion of starch that escapes the enzymatic digestion and absorption in the small intestine. The undigested starch reaches the distal small intestine and hindgut for microbial fermentation, which produces short-chain fatty acids (SCFA) for absorption. SCFA in turn, influence microbial ecology and gut health of pigs. These fermentative metabolites exert their benefits on gut health through promoting growth and proliferation of enterocytes, maintenance of intestinal integrity and thus immunity, and modulation of the microbial community in part by suppressing the growth of pathogenic bacteria while selectively enhancing beneficial microbes. Thus, RS has the potential to confer prebiotic effects and may contribute to the improvement of intestinal health in pigs during the post-weaning period. Despite these benefits to the well-being of pigs, RS has a contradictory effect due to lower energetic efficiency of fermented vs. digested starch absorption products. The varying amount and type of RS interact differently with the digestion process along the gastrointestinal tract affecting its energy efficiency and host physiological responses including feed intake, energy metabolism, and feed efficiency. Results of research indicate that the use of RS as prebiotic may improve gut health and thereby, reduce the incidence of post-weaning diarrhea (PWD) and associated mortality. This review summarizes our current knowledge on the effects of RS on microbial ecology, gut health and growth performance in pigs.

Hindgut fermentation of starch is greater for pulse grains than cereal grains in growing pigs

The nutritive value of starch, the major source of dietary energy in pigs, varies depending on its susceptibility for digestion. The botanical origin of starch determines starch structure, and therefore, digestibility. To compare digestibility of starch, fiber, gross energy (GE), crude protein, and amino acid (AA), and to characterize undigested starch of grains in growing pigs, seven ileal-cannulated barrows (initial body weight, 30 kg) were fed six diets containing 96% of one of six test ingredients (three pulse grains: zero-tannin faba bean, green field pea, or mixed-cultivar chickpea; three cereal grains: hulled barley, hard red spring wheat, or hybrid yellow, dent corn), or a N-free diet in a 7 × 7 Latin square at 2.8 × maintenance digestible energy. Grain samples were ground with a hammer mill through a 2.78-mm screen. Amylose content ranged from 29% to 34% for pulse grains and from 22% to 25% for cereal grains. The apparent ileal digestibility (AID) of starch was greater (P < 0.05) in cereal (94% to 97%) than pulse grains (85% to 90%) and was lowest (P < 0.05) in faba bean (85.3%) followed by field pea (87.2%) and chickpea (90.1%). However, apparent total tract digestibility (ATTD) of starch of all tested grains was close to 100%. Apparent hindgut fermentability (AHF, as ATTD - AID) of starch was greater (P < 0.05) in pulse grains (9.9% to 15%) than cereal grains (3.3% to 4.8%). The AHF of total dietary fiber tended to be the greatest (P < 0.10) for corn (43.5%) and lowest for wheat (25.3%). The AHF of GE was greater (P < 0.05) in pulse grains (17% to 20%) than in cereal grains (9% to 11%) and resulted in greater (P < 0.05) digestible energy (DE) contribution from hindgut fermentation for pulse grains than cereal grains (0.9 vs. 0.5 Mcal/kg). Wheat had the greatest standardized ileal digestibility of total AA (90.2%; P < 0.05). Confocal laser scanning microscopy images revealed that 20% to 30% of starch granules of pulse grains were entrapped in protein matrixes. In scanning electron microscopy images, starch granules were larger in faba bean and field pea than cereal grains. Digesta samples revealed pin holes and surface cracks in starch granules of corn and wheat, respectively. In conclusion, hindgut fermentation of starch and fiber was greater in pulse grains than cereal grains resulting in a greater DE value despite lower ileal DE for pulse grain than cereal grains. Defining the digestible and fermentable fractions of starch may enhance the accuracy of equations to predict the net energy value of these feedstuffs.

Pediatric intestinal failure and the microbiome

Neonatal intestinal failure is a complex medical condition that is associated with the need for long term parenteral nutrition and its associated complications. The microbiome in this diseased state is different from what is now understood to be a healthy microbiome. The effect of this dysbiotic microbiome on the complications of intestinal failure are only starting to be understood. The ability to modulate the microbiome with enteral/parenteral nutrients, as well probiotics to a healthier state, is an exciting opportunity that holds promise.

Net energy, energy utilization, and nitrogen and energy balance affected by dietary pea supplementation in broilers

Pea starch consists predominantly of C-type of amylopectin chain which is more resistant to digestive enzymes than A-type of starch thus slowly digested in poultry. It was hypothesized that the presence of slowly digested pea starch in broiler diets will increase net energy and the efficiency of energy utilization in broilers. Two experiments were performed to investigate starch digestibility of pea at different incubation times (in vitro study) and the effect of dietary pea on heat increment and net energy in broilers using an open-circuit respiratory calorimetry system (in vivo study). One-day-old Ross 308 male broilers were fed a common starter crumble from d 1 to 10 and standard grower diets thereafter. At d 21, birds were transferred to the chambers each housing 2 birds. Each treatment was replicated 6 times with 2 identical runs of 3 replicates per treatment. A wheat-soybean meal-based diet was used as a control and the treatment diet contained 500 g of pea/kg pea. In vitro study showed that pellet processing increased (P < 0.001) starch digestibility, particularly at shorter times for wheat and a much larger response for pea. Birds offered the pea-based diet had lower (P = 0.002) feed intake, lower (P = 0.020) body weight gain, but a similar (P > 0.05) FCR compared to those offered the wheat-based diet. Net energy (NE) and apparent metabolizable energy (AME) values were higher in the pea-based diet than in the wheat-based diet (P = 0.037 for NE and P = 0.018 for AME). Heat production, respiratory quotient, heat increment of feed, efficiency of utilization of gross energy for AME, and efficiency of utilization of AME for NE did not differ (P > 0.05) between the 2 treatments. There was no effect (P > 0.05) of pea on the total tract digestibilities of dry matter, crude protein and ash, but the total tract digestibility of starch was higher (P = 0.022) in the pea-based diet compared to the wheat-based diet. This study provides insight into the energy metabolism of broilers offered a pea-based diet and indicates that dietary pea supplementation increases dietary AME and NE but has no effect on heat increment of feed and the efficiency of energy utilization in broilers.

Toxicity of Canola-Derived Glucosinolate Degradation Products in Pigs-A Review

Canola co-products are widely included in swine diets as sources of proteins. However, inclusion of canola co-products in diets for pigs is limited by toxicity of glucosinolate degradation products. Aliphatic and aromatic glucosinolates are two major classes of glucosinolates. Glucosinolate degradation products derived from aliphatic glucosinolates (progoitrin) include crambene, epithionitriles, and goitrin, whereas indole-3-acetonitrile, thiocyanate, and indole-3-carbinol are the major aromatic glucosinolates (glucobrassicin)-derived degradation products. At acidic pH (<5.7), progoitrin is degraded by myrosinases to crambene and epithionitriles in the presence of iron, regardless of the presence of epithiospecifier protein (ESP), whereas progoitrin is degraded by myrosinases to goitrin in the absence of ESP, regardless of the presence of iron at neutral pH (6.5). Indole-3-acetonitrile is the major degradation product derived from glucobrassicin in the absence of ESP, regardless of the presence of iron at acidic pH (<4.0), whereas thiocyanate and indole-3-carbinol are the major glucobrassicin-derived degradation products in the absence of ESP, regardless of the presence of iron at neutral pH (7.0). In conclusion, the composition of glucosinolate degradation products is affected by parent glucosinolate composition and hindgut pH. Thus, toxicity of canola co-product-derived glucosinolates can be potentially alleviated by modifying the hindgut pH of pigs.

Toxicity of canola-derived glucosinolates in pigs fed resistant starch-based diets

A study was conducted to determine effects of reducing hindgut pH through dietary inclusion of high-amylose cornstarch (HA-starch) on growth performance, organ weights relative to live body weight (BW), blood thyroid hormone levels, and glucosinolate degradation products of nursery pigs fed cold-pressed canola cake (CPCC). A total of 240 pigs (initial BW: 7.1 kg), which had been weaned at 21 d of age, were housed in 40 pens (6 pigs per pen) and fed 4 diets (10 pens per diet) in a randomized complete block design for 28 d. Four diets were a basal diet with CPCC at 0 or 40%, and with HA-starch at 0 or 40% in a 2 × 2 factorial arrangement. The diets were fed in two phases: Phase 1 from day 0 to 14 and Phase 2 from day 14 to 28 and were formulated to have the same net energy, standardized ileal digestible AA, Ca, and standardized total tract digestible P contents. Dietary inclusion of CPCC and HA-starch was achieved by a partial or complete replacement of corn, soybean meal, and soy protein. At the end of the study, one pig from each pen was euthanized to determine organ weights, blood parameters, hindgut pH, and glucosinolate degradation products. Dietary CPCC reduced (P < 0.05) overall average daily gain (ADG) by 15%; increased (P < 0.05) relative weights of liver and thyroid gland by 27% and 64%, respectively; and reduced (P < 0.05) serum tetraiodothyronine (T4) level from 30.3 to 17.8 ng/mL. Heart, kidney, and gastrointestinal tract weights; serum triiodothyronine level; and hindgut pH of pigs were unaffected by dietary CPCC. Dietary HA-starch reduced (P < 0.05) overall ADG, relative weight of thyroid gland, cecal, and colonic pH; but increased (P < 0.05) relative weight of colon; tended to increase (P = 0.062) serum T4 level. Dietary CPCC and HA-starch interacted (P = 0.024) on relative weight of thyroid gland such that dietary CPCC increased (P < 0.05) weight of thyroid gland for HA-starch-free diet (120 vs. 197 mg/kg of BW) but not for HA-starch-containing diet (104 vs. 130 mg/kg of BW). Dietary CPCC and HA-starch interacted (P = 0.001) on cecal isothiocyanate content such that dietary CPCC increased (P < 0.05) level of isothiocyanates for HA-starch-containing diet but not for HA-starch-free diet. In conclusion, dietary CPCC reduced growth performance, increased liver, size and interfered with thyroid gland functions of pigs. However, the negative effects of dietary CPCC on thyroid gland functions of nursery pigs were alleviated by dietary HA-starch.

Clostridium species as probiotics: potentials and challenges

Clostridium species, as a predominant cluster of commensal bacteria in our gut, exert lots of salutary effects on our intestinal homeostasis. Up to now, Clostridium species have been reported to attenuate inflammation and allergic diseases effectively owing to their distinctive biological activities. Their cellular components and metabolites, like butyrate, secondary bile acids and indolepropionic acid, play a probiotic role primarily through energizing intestinal epithelial cells, strengthening intestinal barrier and interacting with immune system. In turn, our diets and physical state of body can shape unique pattern of Clostridium species in gut. In view of their salutary performances, Clostridium species have a huge potential as probiotics. However, there are still some nonnegligible risks and challenges in approaching application of them. Given this, this review summarized the researches involved in benefits and potential risks of Clostridium species to our health, in order to develop Clostridium species as novel probiotics for human health and animal production.

Assessing the effect of starch digestion characteristics on ileal brake activation in broiler chickens

The objective of this research was to evaluate activation of the ileal brake in broiler chickens using diets containing semi-purified wheat (WS; rapidly and highly digested) and pea (PS; slowly and poorly digested) starch. Diets were formulated to contain six WS:PS ratios (100:0, 80:20, 60:40, 40:60, 20:80, 0:100) and each starch ratio was fed to 236 Ross 308 male broilers housed in 4 litter floor pens. At 28 d of age, the effect of PS concentration was assessed on starch digestion, digestive tract morphology, and digesta pH and short-chain fatty acid (SCFA) concentration. Glucagon-like peptide-1 (GLP-1) and peptide tyrosine-tyrosine (PYY) status were assessed in serum (ELISA) and via gene expression in jejunal and ileal tissue (proglucagon for GLP-1). Data were analyzed using regression analyses, and significance was accepted at P ≤ 0.05. Increasing dietary PS resulted in reduced starch digestibility in the small intestine, but had no effect in the colon. Crop content pH responded quadratically to PS level with an estimated minimum at 55% PS. Total SCFA increased linearly in the crop with PS level, but changed in a quadratic fashion in the ileum (estimated maximum at 62% PS). Ceacal SCFA concentrations were highest for the 80 and 100% PS levels. The relative empty weight (crop, small intestine, colon), length (small intestine) and content (crop jejunum, Ileum) of digestive tract sections increased linearly with increasing PS concentration. Dietary treatment did not affect serum GLP-1 or PYY or small intestine transcript abundance. In conclusion, feeding PS increased the presence of L-cell activators (starch, SCFA) and increased trophic development and content of the digestive tract, suggestive of L-cell activation. However, no direct evidence of ileal brake activation was found by measuring venous blood levels of GLP-1 or PYY or corresponding gene expression in small intestine tissue.

Digestive enzyme expression in the large intestine of children with short bowel syndrome in a late stage of adaptation

BACKGROUND AND AIMS

Intestinal adaptation in short bowel syndrome (SBS) includes morphologic processes and functional mechanisms. This study investigated whether digestive enzyme expression in the duodenum and colon is upregulated in SBS patients.

METHOD

Sucrase-isomaltase (SI), lactase-phlorizin hydrolase (LPH), and neutral Aminopeptidase N (ApN) were analyzed in duodenal and colonic biopsies from nine SBS patients in a late stage of adaptation as well as healthy and disease controls by immunoelectron microscopy (IEM), Western blots, and enzyme activities. Furthermore, proliferation rates and intestinal microbiota were analyzed in the mucosal specimen.

RESULTS

We found significantly increased amounts of SI, LPH, and ApN in colonocytes in most SBS patients with large variation and strongest effect for SI and ApN. Digestive enzyme expression was only partially elevated in duodenal enterocytes due to a low proliferation level measured by Ki-67 staining. Microbiome analysis revealed high amounts of Lactobacillus resp. low amounts of Proteobacteria in SBS patients with preservation of colon and ileocecal valve. Colonic expression was associated with a better clinical course in single cases.

CONCLUSION

In SBS patients disaccharidases and peptidases can be upregulated in the colon. Stimulation of this colonic intestinalization process by drugs, nutrients, and pre- or probiotics might offer better therapeutic approaches.

Influences of dietary starch structure on intestinal morphology, barrier functions, and epithelium apoptosis in weaned pigs

The objective of the present study was to evaluate the effects of dietary starch structure on intestinal health of weaned pigs by determining the intestinal morphology, barrier functions, epithelium apoptosis and digestive enzymes.

Feed intake patterns nor growth rates of pigs are affected by dietary resistant starch, despite marked differences in digestion

Current feed evaluation systems often assume that fermented starch (i.e. resistant starch (RS)) yields less energy than digested starch. However, growth rates of pigs fed low and high RS diets are often the same when feed is available ad libitum. This may be explained by its effect on digestive processes changing feeding behavior, and consequently energy utilization. This study aims to investigate the effect of RS on nutrient digestion and digesta passage rate in pigs, in combination with its effect on feeding behavior and growth performance under ad libitum conditions. In experiment 1, 20 male pigs (40 ± 2.82 kg) were fed diets containing either 50% waxy maize starch (low in RS (LRS)) or high-amylose maize starch (high in RS (HRS)), and soluble and insoluble indigestible markers. After 14 days of adaptation to the diets, pigs were fed hourly to reach steady state (6 h), dissected, and digesta were collected from eight segments. From the collected samples, nutrient digestion and passage rate of the solid and liquid digesta fraction were determined. In experiment 2, 288 pigs (80 ± 0.48 kg; sex ratio per pen 1 : 1; boar : gilt) were housed in groups of 6. Pigs were ad libitum-fed one of the experimental diets, and slaughtered at approximately 115 kg. Feed intake, growth and carcass parameters were measured. Ileal starch digestibility was greater for LRS-fed than for HRS-fed pigs (98.0% v. 74.0%; P < 0.001), where the additional undigested starch in HRS-fed pigs was fermented in the large intestine. No effects of RS on digesta passage rate of the solid or liquid digesta fraction and on feeding behavior were observed. Growth rate and feed intake did not differ between diets, whereas feed efficiency of HRS-fed pigs was 1%-unit higher than that of LRS-fed pigs (P = 0.041). The efficiency of feed used for carcass gain did not differ between diets indicating that the difference in feed efficiency was determined by the non-carcass fraction. Despite a 30% greater RS intake (of total starch) with HRS than with LRS, carcass gain and feed efficiency used for carcass gain were unaffected. RS did not affect digesta passage rate nor feeding behavior suggesting that the difference in energy intake between fermented and digested starch is compensated for post-absorptively. Our results indicate that the net energy value of fermented starch currently used in pig feed evaluation systems is underestimated and should be reconsidered.

Growth performance, carcass traits and digestive function of broiler chickens fed diets with graded levels of corn resistant starch

1. This study was conducted to assess the effects of graded levels of dietary corn resistant starch (RS) on growth performance, carcass traits, nutrient retention, digestive organ index, intestinal morphology, digestive enzyme activities, and mRNA expression of certain nutrient transporters in broiler chickens.2. A total of 320, 1-d-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments, with eight replicates of eight birds in each. These treatments included one corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets supplemented with 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% of Hi-Maize 260® (identified as control, RS1, RS2, RS3 and RS4, respectively). The feeding period lasted 42 days.3. Performance parameters including feed consumption, feed conversion, body weight gain and percentage of abdominal fat at d 42 of age, nutrient retention (including dry matter, fat, total starch and nitrogen free extract), and apparent metabolisable energy was measured from d 18 to 20 and d 39 to 41 and showed negative linear responses to increasing dietary RS level (P < 0.05). Birds fed the RS3 and RS4 diets showed higher relative weight of duodenum, jejunum and ileum, as well as lower villus height and villus height/crypt depth compared to the control (P < 0.05). The activity of pancreatic trypsin of birds at d 21 and 42 of age decreased linearly in response to the increase of dietary RS level (P < 0.01). There were linear changes in up-regulated mRNA expression of SGLT-1 and down-regulated mRNA expression of GLUT-2 with increasing proportion of RS at d 21 and 42 of age (P < 0.05), respectively.4. It was concluded that feeding broilers with diets containing higher concentrations of RS impaired the development of small intestine, which resulted in lower apparent total tract retention of nutrients and poorer body weight gain, feed efficiency and carcass traits of broiler chickens.

Dietary Supplementation With Citrus Extract Altered the Intestinal Microbiota and Microbial Metabolite Profiles and Enhanced the Mucosal Immune Homeostasis in Yellow-Feathered Broilers

The present study aimed to investigate the effects of citrus extract (CE) on intestinal microbiota, microbial metabolite profiles, and the mucosal immune status in broilers. A total of 540 one-day-old yellow-feathered broilers were randomly allotted into three groups and fed a basal diet (control group), or a basal diet containing 10 mg/kg of zinc bacitracin (antibiotic group), or 10 mg/kg of CE (CE group). Each treatment consisted of six replicates, with 30 broilers per replicate. After 63-day feeding, two broilers per replicate were randomly selected and slaughtered, and their ileal and cecal digesta and ileal tissue were collected for microbial composition, microbial metabolites, and gene expression analysis. The results showed that CE significantly increased the abundance of Barnesiella and Blautia than did the antibiotic group (adjusted P < 0.05), whereas it decreased the abundance of Alistipes and Bacteroides (adjusted P < 0.05). Meanwhile, the CE group also increased the numbers of Bifidobacterium and Lactobacillus than did the control and antibiotic groups (P < 0.05), whereas it decreased the number of Escherichia coli (P < 0.05). For microbial metabolites, dietary supplementation with CE increased the concentrations of lactate, total short-chain fatty acids, acetate, and butyrate in the cecum than did the control and antibiotic groups (P < 0.05), whereas it decreased the concentrations of amino acid fermentation products (ammonia, amines, p-cresol, and indole) (P < 0.05). Additionally, supplementation with CE up-regulated (P < 0.05) the mRNA expression of intestinal barrier genes (ZO-1 and Claudin) in the ileum than did both the control and antibiotic groups. However, antibiotic treatment induced gut microbiota dysbiosis, altered the microbial metabolism, and disturbed the innate immune homeostasis. In summary, these results provide evidence that dietary supplementation with CE can improve the intestinal barrier function by changing microbial composition and metabolites, likely toward a host-friendly gut environment. This suggests that CE may possibly act as an efficient antibiotic alternative for yellow-feathered broiler production.

Effect of mucin 4 allele on susceptibility to experimental infection with enterotoxigenic F4 Escherichia coli in pigs fed experimental diets

Background

This study investigated the validity of the DNA-marker based test to determine susceptibility to ETEC-F4 diarrhoea by comparing the results of two DNA sequencing techniques in weaner pigs following experimental infection with F4 enterotoxigenic Escherichia coli (ETEC-F4). The effects of diet and genetic susceptibility were assessed by measuring the incidence of piglet post-weaning diarrhoea (PWD), faecal E. coli shedding and the diarrhoea index.

Results

A DNA marker-based test targeting the mucin 4 gene (MUC4) that encodes F4 fimbria receptor identified pigs as either fully susceptible (SS), partially or mildly susceptible (SR), and resistant (RR) to developing ETEC-F4 diarrhoea. To further analyse this, DNA sequencing was undertaken, and a significantly higher proportion of C nucleotides was observed for RR and SR at the XbaI cleavage site genotypes when compared to SS. However, no significant difference was found between SR and RR genotypes. Therefore, results obtained from Sanger sequencing retrospectively allocated pigs into a resistant genotype (MUC4–), in the case of a C nucleotide, and a susceptible genotype (MUC4+), in the case of a G nucleotide, at the single nucleotide polymorphism site. A total of 72 weaner pigs (age ~ 21 days), weighing 6.1 ± 1.2 kg (mean ± SEM), were fed 3 different diets: (i) positive control (PC) group supplemented with 3 g/kg zinc oxide (ZnO), (ii) negative control (NC) group (no ZnO or HAMSA), and (iii) a diet containing a 50 g/kg high-amylose maize starch product (HAMSA) esterified with acetate. At days five and six after weaning, all pigs were orally infected with ETEC (serotype O149:F4; toxins LT1, ST1, ST2 and EAST). The percentage of pigs that developed diarrhoea following infection was higher (P = 0.05) in MUC4+ pigs compared to MUC4– pigs (50% vs. 26.8%, respectively). Furthermore, pigs fed ZnO had less ETEC-F4 diarrhoea (P = 0.009) than pigs fed other diets, however faecal shedding of ETEC was similar (P > 0.05) between diets.

Conclusion

These results confirm that MUC4+ pigs have a higher prevalence of ETEC-F4 diarrhoea following exposure, and that pigs fed ZnO, irrespective of MUC4 status, have reduced ETEC-F4 diarrhoea. Additionally, sequencing or quantifying the single nucleotide polymorphism distribution at the XbaI cleavage site may be more reliable in identifying genotypic susceptibility when compared to traditional methods.

The Capacity of the Fecal Microbiota From Malawian Infants to Ferment Resistant Starch

In Low and Middle-Income Countries (LMIC), weaning is associated with environmentally acquired and inflammation-associated enteric disorders. Dietary intake of high amylose maize starch (HAMS) can promote commensal fermentative bacteria and drive the production of short chain fatty acids (SCFAs). By stabilizing commensal gut microbiology, and stimulating the production of anti-inflammatory metabolites, HAMS supplementation might therefore influence enteric health. However, the extent to which the gut microbiota of LMIC infants are capable of fermenting HAMS is unclear. We assessed the capacity of the fecal microbiota from pre-weaning and weaning Malawian infants to ferment HAMS and produce SCFAs using an in vitro fermentation model. Fecal microbiota from both pre-weaning and weaning infants were able to ferment HAMS, as indicated by an increase in bacterial load and total SCFA concentration, and a reduction in pH. All of these changes were more substantial in the weaning group. Acetate production was observed with both pre-weaning and weaning groups, while propionate production was only observed in the weaning group. HAMS fermentation resulted in significant alterations to the fecal microbial community in the weaning group, with significant increases in levels of Prevotella, Veillonella, and Collinsella associated with propionate production. In conclusion, fecal microbiota from Malawian infants before and during weaning has the capacity to produce acetate through HAMS fermentation, with propionate biosynthetic capability appearing only at weaning. Our results suggest that HAMS supplementation might provide benefit to infants during weaning.

Dietary Resistant Potato Starch Alters Intestinal Microbial Communities and Their Metabolites, and Markers of Immune Regulation and Barrier Function in Swine

Interactions between diet, the microbiota, and the host set the ecological conditions in the gut and have broad implications for health. Prebiotics are dietary compounds that may shift conditions toward health by promoting the growth of beneficial microbes that produce metabolites capable of modulating host cells. This study's objective was to assess how a dietary prebiotic could impact host tissues via modulation of the intestinal microbiota. Pigs fed a diet amended with 5% resistant potato starch (RPS) exhibited alterations associated with gut health relative to swine fed an unamended control diet (CON). RPS intake increased abundances of anaerobic Clostridia in feces and several tissues, as well as intestinal concentrations of butyrate. Functional gene amplicons suggested bacteria similar to Anaerostipes hadrus were stimulated by RPS intake. The CON treatment exhibited increased abundances of several genera of Proteobacteria (which utilize respiratory metabolisms) in several intestinal locations. RPS intake increased the abundance of regulatory T cells in the cecum, but not periphery, and cecal immune status alterations were indicative of enhanced mucosal defenses. A network analysis of host and microbial changes in the cecum revealed that regulatory T cells positively correlated with butyrate concentration, luminal IgA concentration, expression of IL-6 and DEF1B, and several mucosa-associated bacterial taxa. Thus, the administration of RPS modulated the microbiota and host immune status, altering markers of cecal barrier function and immunological tolerance, and suggesting a reduced niche for bacterial respiration.

Resistant Starch is Actively Fermented by Infant Faecal Microbiota and Increases Microbial Diversity

In adults, fermentation of high amylose maize starch (HAMS), a resistant starch (RS), has a prebiotic effect. Were such a capacity to exist in infants, intake of RS might programme the gut microbiota during a critical developmental period. This study aimed to determine if infant faecal inocula possess the capacity to ferment HAMS or acetylated-HAMS (HAMSA) and characterise associated changes to microbial composition. Faecal samples were collected from 17 healthy infants at two timepoints: Preweaning and within 10 weeks of first solids. Fermentation was assessed using in vitro batch fermentation. Following 24 h incubation, pH, short-chain fatty acid (SCFA) production and microbial composition were compared to parallel control incubations. In preweaning infants, there was a significant decrease at 24 h in pH between control and HAMS incubations and a significant increase in the production of total SCFAs, indicating fermentation. Fermentation of HAMS increased further following commencement of solids. Fermentation of RS with weaning faecal inocula increased Shannon's diversity index (H) and was associated with increased abundance of Bifidobacterium and Bacteroides. In conclusion, the faecal inocula from infants is capable of RS fermentation, independent of stage of weaning, but introduction of solids increases this fermentation capacity. RS may thus function as a novel infant prebiotic.

Microbiome-Metabolomics Analysis Investigating the Impacts of Dietary Starch Types on the Composition and Metabolism of Colonic Microbiota in Finishing Pigs

The present study used a combination of 16S rRNA MiSeq sequencing strategy and gas chromatograph time of flight mass spectrometer (GC-TOF/MS) technique to investigate the effects of starch sources on the colonic microbiota and their metabolites in finishing pigs. A total of 72 crossbred barrows were allocated to three different experimental diets with eight replicates and three pigs per replicate. The diet types included tapioca starch (TS), corn starch (CS), and pea starch (PS) (amylose/amylopectin were 0.11, 0.25, and 0.44, respectively). Results showed that the PS diet markedly increased (adjusted P < 0.05) the abundance of short-chain fatty acids (SCFAs) and lactate producers, such as Lactobacillus, Prevotella, Faecalibacterium, and Megasphaera, while decreased (adjusted P < 0.05) the abundance of Escherichia coli when compared with the TS diet. The metabolomic and biochemistry analyses demonstrated that the PS diet increased (adjusted P < 0.05) the concentrations of organic acids (acetate, propionate, butyrate, valerate, and lactate) and some macronutrients (sugars and long-chain fatty acids), and decreased (adjusted P < 0.05) the amino acids and their derivatives (leucine, glycine, putrescine, cadaverine, skatole, indole, and phenol) when compared with the TS diet. Additionally, Spearman’s correlation analysis revealed that the changes in the colonic metabolites were associated with changes in the microbial composition. Correlatively, these findings demonstrated that the different dietary starch types treatment significantly altered the intestinal microbiota and metabolite profiles of the pigs, and dietary with higher amylose may offer potential benefits for gut health.

Dietary Fiber and Intestinal Health of Monogastric Animals

Animal performance, feed efficiency, and overall health are heavily dependent on gut health. Changes in animal production systems and feed regulations away from the use of antibiotic growth promoters (AGP) have necessitated the identification of strategies to optimize gut health in novel and effective ways. Among alternatives to AGP, the inclusion of dietary fibers (DF) in monogastric diets has been attempted with some success. Alternative feedstuffs and coproducts are typically rich in fiber and can be used in the diets to reduce feed costs and optimize gut health. DF are naturally occurring compounds with a diverse composition and are present in all plant-based feedstuffs. DF stimulate the growth of health-promoting gut bacteria, are fermented in the distal small intestine and large intestine to short-chain fatty acids and have beneficial effects on the immune system. Maternal DF supplementation is one novel strategy suggested to have a beneficial programming effect on the microbial and immune development of their offspring. One mechanism by which DF improves gut health is through maintenance of an anaerobic intestinal environment that subsequently prevents facultative anaerobic pathogens from flourishing. Studies with pigs and poultry have shown that fermentation characteristics and their beneficial effects on gut health vary widely based on type, form, and the physico-chemical properties of the DF. Therefore, it is important to have information on the different types of DF and their role in optimizing gut health. This review will provide information and updates on different types of DF used in monogastric nutrition and its contribution to gut health including microbiology, fermentation characteristics, and innate and adaptive immune responses.

Reduced Feed Intake, Rather than Increased Energy Losses, Explains Variation in Growth Rates of Normal-Birth-Weight Piglets

Background

Substantial variation in growth rates exists in normal-birth-weight piglets, possibly due to differences in energy efficiency. Within this population, slow growth rates are associated with reduced insulin sensitivity. Slowly digestible starch (SDS) may improve growth efficiency in slowly growing pigs, because it reduces postprandial blood glucose.

Objective

The aim of this study was to investigate maintenance energy requirements and efficiency of energy used for growth (incremental energy efficiency) of slow-growing or fast-growing piglets (SG-pigs and FG-pigs, respectively) with equal birth weight that were fed either an SDS or a rapidly digestible-starch (RDS) diet.

Methods

Sixteen groups of either five 10-wk-old SG-pigs (mean ± SD: 11.3 ± 1.4 kg) or FG-pigs (15.1 ± 1.7 kg) were housed in climate respiration chambers and fed diets containing 40% RDS or SDS for 2 wk. In week 1, feed was available ad libitum. In week 2, feed supply was restricted to 65% of the observed weekly averaged feed intake [kJ · kg body weight (BW)-0.6 · d-1] in week 1. After week 2, pigs were feed deprived for 24 h, after which heat production was determined. Energy balances, apparent total tract digestibility (ATTD), and incremental energy efficiencies were calculated and analyzed using a general linear model.

Results

Gross energy intake (kJ · kg BW-0.6 · d-1) was 4% greater (P = 0.047) for FG-pigs than for SG-pigs. ATTD of fat was 6%-units greater (P = 0.003) for RDS-fed than for SDS-fed pigs. Fasting heat production and incremental energy efficiencies did not differ between pig types or diets. Incremental use of metabolizable energy for fat retention was 2% units (P = 0.054) greater for RDS-fed than SDS-fed pigs.

Conclusions

A lower energy intake rather than greater maintenance requirements or lower energy efficiency explains the slow growth of SG-pigs. Incremental RDS intake increased fat deposition more than SDS, whereas energy efficiency was not affected. Thus, feeding SDS instead of RDS does not improve growth efficiency but may result in slightly leaner pigs.

Growth performance, nutrient digestibility, and selected fecal microbiota are improved by β-glucan supplementation in weaner pigs

This study was conducted to evaluate the effects of dietary β-glucan supplementation on growth performance, nutrient digestibility, blood profiles, and fecal characteristics in weaner pigs. A total of 140 weaner pigs [(Yorkshire × Landrace) × Duroc] with an average body weight of 6.37±1.14 kg were allotted to one of the following dietary treatments: 1) negative control (NC, basal diet); 2) positive control (PC, basal diet supplemented with 39 ppm Tiamulin); 3) basal diet supplemented with 0.1% β-glucan (G1); 4) basal diet supplemented with 0.2% β-glucan (G2). During days 22 to 42 and 1 to 42, pigs offered PC and G2 diets grew faster than those offered NC diet (P<0.05). Additionally, during the same periods, pigs fed G2 and PC diets exhibited improved gain:feed ratio compared to pigs receiving NC and G1 diets (P<0.05). Pigs fed G2 diet exhibited higher coefficient of total tract apparent digestibility of dry matter than those fed NC diet (P<0.05). There were no differences on blood profiles, fecal scores, fecal moisture, and fecal pH (P>0.05). Fecal lactic acid bacteria counts in G2 treatment were higher compared with PC and NC treatments (P<0.05). Coliform bacteria concentrations were decreased in pigs fed PC and G2 diets compared with those fed NC diet (P<0.05). In conclusion, the results of the current study indicate that dietary supplementation of 0.2% β-glucan can improve growth performance and dry matter digestibility, increase fecal lactic acid bacteria concentration but decrease fecal coliform bacteria concentration in weaner pigs.

Starch Tolerance and the Short Bowel

Short bowel syndrome with intestinal failure is a rare disease with a massive impairment in quality of life, requiring a multidisciplinary team approach to medical, surgical, and nutritional therapy. Current pharmacological and surgical therapeutic options are limited; an important cornerstone is enteral and parenteral nutrition. The changed physiology of carbohydrate digestion plays a major role in the adaptation process and can be a target for specific enteral nutrition interventions. An important prognostic factor is the preservation of at least portions of the colon in continuity with small bowel. This strategy has to include an evaluation of the anatomical situation and small bowel absorptive capacity, adaptation processes, and luminal microbiota including its fermentative properties. Starch is probably the most important complex carbohydrate in short bowel syndrome nutrition, because it is absorbed or fermented almost completely. Benefits of supplementation with complex carbohydrates include improved adaptive processes, positive trophic effects on the mucosa and its hormonal response, longer transit time, and possibly a faster time to wean from parenteral nutrition, but supplementation advice needs to weigh carefully the risks and benefits, especially considering bacterial overgrowth, osmotic load, and D-lactate acidosis.

Modifications in gut microbiota and fermentation metabolites in the hindgut of rats after the consumption of galactooligosaccharide glycated with a fish peptide

The glycation-induced modification of GOS by mild thermal treatments greatly increased its persistence of fermentation in the colon of the host, and improved some prebiotic activities.

Whole-Grain Starch and Fiber Composition Modifies Ileal Flow of Nutrients and Nutrient Availability in the Hindgut, Shifting Fecal Microbial Profiles in Pigs

Background: Changes in whole-grain chemical composition can affect the site of nutrient digestion, which may alter substrate availability and gut microbiota composition.Objective: This study elucidated the function of whole-grain fermentable fiber composition on ileal substrate flow, hindgut substrate availability, and subsequent gut microbial profiles in pigs.Methods: Five whole grains-1) high-fermentability, high-β-glucan hull-less barley (HFB); 2) high-fermentability, high-amylose hull-less barley (HFA); 3) moderate-fermentability hull-less barley (MFB); 4) low-fermentability hulled barley (LFB); or 5) low-fermentability hard red spring wheat (LFW)-were included at 800 g/kg into diets fed to ileal-cannulated growing pigs for 9 d in a 6 (periods) × 5 (diets) Youden square. Digesta were analyzed for nutrient flow and microbial composition via 16S ribosomal RNA gene sequencing.Results: The consumption of fermentable whole grains, HFB, and HFA increased (P < 0.05) ileal starch flow by 69% and dry matter flow by 37% compared with LFB and LFW intakes. The consumption of HFB and HFA increased (P < 0.05) fecal Firmicutes phylum abundance by 26% and 21% compared with LFB intake and increased (P < 0.05) fecal Dialister genus abundance, on average, by 98% compared with LFB and LFW intakes. Fecal Sharpea and Ruminococcus genera abundances increased (P < 0.05) with HFB intake compared with LFB and LFW intakes. In contrast, the consumption of LFB increased (P < 0.05) fecal Bacteroidetes phylum abundance by 43% compared with MFB intake. Ileal starch flow and fecal Firmicutes abundance were positively correlated and determined by using principal components analysis.Conclusions: Increasing dietary fermentable fiber from whole grains can increase ileal substrate flow and hindgut substrate availability, shifting the fecal microbiota toward Firmicutes phylum members. Thus, digesta substrate flow is important to shape gut microbial profiles in pigs, which indicates that the manipulation of substrate flow should be considered as a tool to modulate gut microbiota composition.

The Probiotic Combination of Bifidobacterium longum subsp. infantis CECT 7210 and Bifidobacterium animalis subsp. lactis BPL6 Reduces Pathogen Loads and Improves Gut Health of Weaned Piglets Orally Challenged with Salmonella Typhimurium

Probiotics have been demonstrated to be useful to enhance gut health and prevent gastrointestinal infections in humans. Additionally, some multi-strain probiotic combinations have been suggested to have greater efficacy than single strains. The objective of this study is to demonstrate the potential of a combination of the probiotic strains: Bifidobacterium longum subsp. infantis CECT 7210 (brand name B. infantis IM1®) and B. animalis subsp. lactis BPL6 to enhance gut health and to ameliorate the outcome of a Salmonella challenge using a weaning piglet model. Seventy-two 28-day-old weanling piglets, 7.7 (±0.28) kg of body-weight, were distributed in a 2 × 2 factorial design; treated or not with the probiotic combination and challenged or not with the pathogen. Animals were orally challenged after an adaptation period (Day 8) with a single dose (5 × 108 cfu) of Salmonella Typhimurium. One animal per pen was euthanized on Day 12 (Day 4 post-inoculation [PI]) and Day 16 (Day 8 PI). All parameters responded to the challenge and 4 deaths were registered, indicating a severe but self-limiting challenge. Improvements registered in the challenged animals due to the probiotic were: increased voluntary feed-intake (P probiotic × challenge = 0.078), reduced fecal excretion of Salmonella (P = 0.028 at Day 1 PI and P < 0.10 at Days 3 and 5 PI), decreased rectal temperature (P probiotic × day = 0.048) and improvements in the villous:crypt ratio (P probiotic × challenge < 0.001). Moreover, general probiotic benefits were observed in both challenged and non-challenged groups: decreased diarrhea scores of the PI period (P = 0.014), improved fermentation profiles on Day 8 PI (increased ileal acetic acid [P = 0.008] and a tendency to lower colonic ammonia concentrations [P = 0.078]), stimulation of intestinal immune response by increasing villous intraepithelial lymphocytes (P = 0.015 on Day 8 PI) and an improved villous:crypt ratio (P = 0.011). In conclusion, the multi-strain probiotic had a positive effect on reducing pathogen loads and alleviating animals in a Salmonella challenge. In addition, enhanced gut health and immunity was recorded in all animals receiving the probiotic, indicating an improvement in the post-weaning outcome.

Whole-Grain Fiber Composition Influences Site of Nutrient Digestion, Standardized Ileal Digestibility of Amino Acids, and Whole-Body Energy Utilization in Grower Pigs

BACKGROUND

Variant chemical composition and physical structure of whole grains may change the site of energy digestion from the small to the large intestine.

OBJECTIVE

We determined the site of nutrient digestion, standardized ileal digestibility (SID) of amino acids (AAs), and net energy (NE) value of barley cultivars that vary in nutrient composition compared with wheat.

METHODS

Ileal-cannulated barrows (27.7 kg initial body weight) were fed diets containing 800 g whole grains/kg alongside a basal and nitrogen-free diet for calculations in a 6 (period) × 7 (diet) Youden square. Diets included 1 of 5 whole grains-1) high-fermentable, high-β-glucan, hull-less barley (HFB); 2) high-fermentable, high-amylose, hull-less barley (HFA); 3) moderate-fermentable, hull-less barley (MFB); 4) low-fermentable, hulled barley (LFB); and 5) low-fermentable, hard red spring wheat (LFW). Intestine nutrient flow and whole-body energy utilization were tested and explained by using whole-grain and digesta confocal laser scanning.

RESULTS

Starch apparent ileal digestibility was 14-29% lower (P < 0.05) in HFB and HFA than in MFB, LFB, and LFW due to the unique embedding of starch within the protein-fiber matrix of HFB and the high amylose content in HFA. Starch hindgut fermentation was 50-130% higher (P < 0.05) in HFB and HFA than in MFB, LFB, and LFW. The SID of indispensable AAs was lower (P < 0.05) in HFB and HFA than in MFB, LFB, and LFW. NE value was 18% higher (P < 0.05) for HFB than for HFA and was not different from MFB, LFB, and LFW.

CONCLUSIONS

Whole grains high in fermentable carbohydrates shifted digestion from the small intestine to the hindgut. NE value depended on the concentration of fermentable fiber and starch and digestible protein, ranging from 2.12-1.76 Mcal/kg in barley to 1.94 Mcal/kg in wheat. High-fiber whole grains may be used as energy substrates for pigs; however, the reduced SID of AAs requires titration of indispensable AAs to maintain growth.

Effects of variety and steeping conditions on some barley components associated with colonic health

BACKGROUND

Butyric acid is produced by degradation of dietary fibre by microbiota and is crucial for maintaining a healthy colon. The physicochemical properties are important for butyric acid formation, and this study aimed to evaluate the use of malting to tailor the functional characteristics of barley dietary fibre. The effect of different steeping conditions was evaluated in laboratory-scale malting experiments with three different barley varieties.

RESULTS

Steeping at 35°C and with 0.4 % (v/v) lactic acid resulted in a higher content of β-glucan and soluble fibre in malts than in those steeped at lower temperature and lower lactic acid concentration. Resistant starch increased, whereas the content of soluble arabinoxylan was lower. Dietary fibre components in Tipple were more affected by steeping conditions than the other varieties. The total contents of iron, phytate and amylose were little influenced by steeping conditions.

CONCLUSION

The selection of steeping conditions during malting influences composition and the characteristics of dietary fibre in barley. However, the choice of barley variety is also important for tailoring of functional ingredients beneficial for colonic health. © 2016 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.