Dietary fiber pectin directly blocks toll-like receptor 2-1 and prevents doxorubicin-induced ileitis

Dietary carbohydrate fibers are known to prevent immunological diseases common in Western countries such as allergy and asthma but the underlying mechanisms are largely unknown. Until now beneficial effects of dietary fibers are mainly attributed to fermentation products of the fibers such as anti-inflammatory short-chain fatty acids (SCFAs). Here, we found and present a new mechanism by which dietary fibers can be anti-inflammatory: a commonly consumed fiber, pectin, blocks innate immune receptors. We show that pectin binds and inhibits, toll-like receptor 2 (TLR2) and specifically inhibits the proinflammatory TLR2-TLR1 pathway while the tolerogenic TLR2-TLR6 pathway remains unaltered. This effect is most pronounced with pectins having a low degree of methyl esterification (DM). Low-DM pectin interacts with TLR2 through electrostatic forces between non-esterified galacturonic acids on the pectin and positive charges on the TLR2 ectodomain, as confirmed by testing pectin binding on mutated TLR2. The anti-inflammatory effect of low-DM pectins was first studied in human dendritic cells and mouse macrophages in vitro and was subsequently tested in vivo in TLR2-dependent ileitis in a mouse model. In these mice, ileitis was prevented by pectin administration. Protective effects were shown to be TLR2-TLR1 dependent and independent of the SCFAs produced by the gut microbiota. These data suggest that low-DM pectins as a source of dietary fiber can reduce inflammation through direct interaction with TLR2-TLR1 receptors

Effects of pectin on fermentation characteristics, carbohydrate utilization, and microbial community composition in the gastrointestinal tract of weaning pigs

Scope: We aimed to investigate the effects of three different soluble pectins on the digestion of other consumed carbohydrates, and the consequent alterations of microbiota composition and SCFA levels in the intestine of pigs. Methods and results: Piglets were fed a low-methyl esterified pectin enriched diet (LMP), a high-methyl esterified pectin enriched diet (HMP), a hydrothermal treated soybean meal enriched diet (aSBM) or a control diet (CONT). LMP significantly decreased the ileal digestibility of starch resulting in more starch fermentation in the proximal colon. In the ileum, low-methyl esterified pectin present was more efficiently fermented by the microbiota than high-methyl esterified pectin present which was mainly fermented by the microbiota in the proximal colon. Treated soybean meal was mainly fermented in the proximal colon and shifted the fermentation of cereal dietary fiber to more distal parts, resulting in high SCFA levels in the mid colon. LMP, HMP, and aSBM decreased the relative abundance of the genus Lactobacillus and increased that of Prevotella in the colon. Conclusion: The LMP, HMP, and aSBM, differently affected the digestion processes compared to the control diet and shaped the colonic microbiota from a Lactobacillus-dominating flora to a Prevotella-dominating community, with potential health-promoting effects.</p

Amylopectin structure and crystallinity explains variation in digestion kinetics of starches across botanic sources in an in vitro pig model

Starch is the main source of energy in commonly used pig diets. Besides effects related to the extent of starch digestion, also several effects related to variation in digestion rate have recently been demonstrated in non-ruminants. Different rates of starch digestion in animals and in in vitro models have been reported, depending on the botanic origin of starch. Starches from different botanic sources differ widely in structural and molecular properties. Predicting the effect of starch properties on in vitro digestion kinetics based on existing literature is hampered by incomplete characterization of the starches, or by a selective choice of starches from a limited number of botanic sources. This research aimed to analyse the relationships between starch properties and in vitro digestion kinetics of pure starches isolated from a broad range of botanic origins, which are used in non-ruminant diets or have a potential to be used in the future. Therefore we studied starch digestion kinetics of potato, pea, corn, rice, barley, and wheat starches, and analysed the granule diameter, number of pores, type and amount of crystalline structure, amylose content and amylopectin side-chain length of all starches. Results Multivariate analysis revealed strong correlations among starch properties, leading us to conclude that effects of most starch characteristics are strongly interrelated. Across all analysed botanic sources, crystalline type and amylopectin chain length showed the strongest correlation with in vitro digestion kinetics. Increased percentages of A–type crystalline structure and amylopectin side chains of DP 6–24 both increased the rate of digestion. In addition, within, but not across, (clusters of) botanic sources, a decrease in amylose content and increase in number of pores correlated positively with digestion kinetics. Conclusion The type of crystalline structure and amylopectin chain length distribution of starch correlate significantly with digestion kinetics of starches across botanic sources in an in vitro pig model. Variation in digestion kinetics across botanic sources is not additively explained by other starch properties measured, but appears to be confined within botanical sources

The importance of amylase action in the porcine stomach to starch digestion kinetics

Starch digestion in the proximal small intestine of pigs exceeds in vitro predictions, suggesting a currently underestimated role for the stomach in starch digestion kinetics. This study aimed to investigate the role of amylase action in the porcine stomach on starch digestion kinetics, including hydrolysis by porcine saliva and degradation by bacterial enzymes present in the stomach. We studied the hydrolysis of starch in pigs fed barley based diets, in which starch was included as isolated powder, ground barley, or extruded barley. We identified soluble maltodextrins originating from starch breakdown in stomach digesta, especially in pigs fed extruded barley. Furthermore, we observed bacterial cells embedded in granular starch with electron microscopy, for pigs fed diets containing isolated barley starch. These observations lead us to measure starch hydrolysis in a dynamic stomach model over the course of a 225 min incubation, in which the pH was step-wise decreased from 6.5 to 2.0. Using this method, feed was either exposed to an enzyme extract obtained from stomach digesta or to porcine saliva. Up to 30 % of starch was hydrolysed into maltodextrins with a degree of polymerisation (DP) <6 when starch was incubated with the enzyme extract obtained from the stomach. Under the same conditions, saliva amylase, with an optimum pH around 7.8, hydrolysed up to 10 % of processed starch into maltodextrins with DP < 6. We conclude that a substantial part of starch may be degraded into oligomers in the porcine stomach by both salivary and bacterial amylases. This implies a considerable role for the stomach on starch digestion kinetics, which is overlooked in current feed evaluation systems.</p

Effects of physicochemical characteristics of feed ingredients on the apparent total tract digestibility of energy, DM, and nutrients by growing pigs

Effects of physicochemical characteristics of feed ingredients on DE and ME and apparent total tract digestibility (ATTD) of GE, DM, and nutrients were determined in growing pigs using ingredients with different ratios between insoluble dietary fiber (IDF) and soluble dietary fiber (SDF). Eighty growing barrows (BW: 48.41 ± 1.50 kg) were allotted to a randomized complete block design with 10 diets and eight replicate pigs per diet. Dietary treatments included a corn-based diet, a wheat-based diet, a corn–soybean meal (SBM) diet, and seven diets based on a mixture of the corn–SBM diet and canola meal, distillers dried grains with solubles (DDGS), corn germ meal (CGM), copra expellers, sugar beet pulp (SBP), synthetic cellulose, or pectin. Values for the ATTD of DM and nutrients were also compared with the in vitro digestibility of GE, DM, and nutrients. Results indicated that the ATTD of GE was greater (P < 0.05) in wheat than in canola meal, DDGS, CGM, copra expellers, SBP, and synthetic cellulose, but not different from corn, SBM, or pectin. SBM had greater (P < 0.05) DE and ME (DM basis) compared with all other ingredients. The concentration of ME (DM basis) was greater (P < 0.05) in wheat than in canola meal, DDGS, CGM, copra expellers, SBP, synthetic cellulose, and pectin, but not different from corn. Stronger correlations between total dietary fiber (TDF) and DE and ME than between ADF or NDF and DE and ME were observed, indicating that TDF can be used to more accurately predict DE and ME than values for NDF or ADF. The DE, ME, and the ATTD of DM in ingredients were positively correlated (P < 0.05) with in vitro ATTD of DM, indicating that the in vitro procedure may be used to estimate DE and ME in feed ingredients. Swelling and water-binding capacity were positively correlated (P < 0.05) with the ATTD of IDF, TDF, non-starch polysaccharides (NSP), and insoluble NSP, and viscosity was positively correlated (P < 0.05) with the ATTD of NDF, IDF, and insoluble NSP, indicating that some physical characteristics may influence digestibility of fiber. However, physical characteristics of feed ingredients were not correlated with the concentration of DE and ME, which indicates that these parameters do not influence in vivo energy digestibility in feed ingredients. It is concluded that the DE and ME in feed ingredients may be predicted from some chemical constituents and from in vitro digestibility of DM, but not from physical characteristics

Reducing dietary crude protein in broiler diets positively affects litter quality without compromising growth performance whereas a reduction in dietary electrolyte balance further improves litter quality but worsens feed efficiency

Reducing crude protein (CP) in broiler feed is a nutritional strategy that allows to partially reduce dietary soybean meal (SBM) inclusions to reduce feed costs, with proven benefits. In addition, reduction of dietary CP leads to a lower dietary electrolyte balance (dEB) due to the concomitant reduction of potassium (K). The aim of the present study is therefore two-fold: 1) to evaluate the potential of reduction of dietary CP until performance drops (1, 2 or 3 % points of reduction) and 2) to combine it with a reduction of dEB (by reducing dietary K) to validate the benefit of reduced dEB/K on litter quality without compromising performance. In total, 9100 male Ross 308 chicks were randomly allotted to 35 pens of 260 broilers. They were fed 5 dietary treatments from 10 to 20d and 20–30d.There was a “positive control” diet (CONTROL; 20.7 % CP in grower, 19.5 % CP in finisher) and 3 levels of dietary CP reduction by 1 % (CP-1 %), 2% (CP-2 %) and 3 % (CP-3 %), all diets formulated to respect at least the ideal AA profile for indispensable AA. In addition, an extra diet called “negative control” (NC CP-3 %) was formulated to have the same ingredient composition as the CP-3 % diet but with lower K and dEB level. Reducing dietary CP as low as 3 % points and maintaining AA and dEB levels resulted in similar or better production performance from 10 to 30d for weight gain, feed intake, feed conversion ratio (FCR) and carcass traits, reduced daily water intake and water-to-feed ratio, excreta N and moisture as well as lower litter moisture and footpad lesions (FPL). Reducing dEB level at − 3 % CP (negative control) increased feed intake and FCR but reduced water intake, water-to-feed ratio, and FPL. It is therefore possible to feed broilers with lower CP diets without compromising performance, with clear benefit on litter quality. As reducing dietary CP is often associated to reduced dietary K, due to lower SBM inclusion, the extent of reduction of K and the control of dEB by Na, Cl and K need to be further explored, especially on litter quality, to facilitate the adoption of low protein diets in practice

Effects of physicochemical characteristics of feed ingredients on the apparent total tract digestibility of energy, DM, and nutrients by growing pigs

Effects of physicochemical characteristics of feed ingredients on DE and ME and apparent total tract digestibility (ATTD) of GE, DM, and nutrients were determined in growing pigs using ingredients with different ratios between insoluble dietary fiber (IDF) and soluble dietary fiber (SDF). Eighty growing barrows (BW: 48.41 ± 1.50 kg) were allotted to a randomized complete block design with 10 diets and eight replicate pigs per diet. Dietary treatments included a corn-based diet, a wheat-based diet, a corn–soybean meal (SBM) diet, and seven diets based on a mixture of the corn–SBM diet and canola meal, distillers dried grains with solubles (DDGS), corn germ meal (CGM), copra expellers, sugar beet pulp (SBP), synthetic cellulose, or pectin. Values for the ATTD of DM and nutrients were also compared with the in vitro digestibility of GE, DM, and nutrients. Results indicated that the ATTD of GE was greater (P < 0.05) in wheat than in canola meal, DDGS, CGM, copra expellers, SBP, and synthetic cellulose, but not different from corn, SBM, or pectin. SBM had greater (P < 0.05) DE and ME (DM basis) compared with all other ingredients. The concentration of ME (DM basis) was greater (P < 0.05) in wheat than in canola meal, DDGS, CGM, copra expellers, SBP, synthetic cellulose, and pectin, but not different from corn. Stronger correlations between total dietary fiber (TDF) and DE and ME than between ADF or NDF and DE and ME were observed, indicating that TDF can be used to more accurately predict DE and ME than values for NDF or ADF. The DE, ME, and the ATTD of DM in ingredients were positively correlated (P < 0.05) with in vitro ATTD of DM, indicating that the in vitro procedure may be used to estimate DE and ME in feed ingredients. Swelling and water-binding capacity were positively correlated (P < 0.05) with the ATTD of IDF, TDF, non-starch polysaccharides (NSP), and insoluble NSP, and viscosity was positively correlated (P < 0.05) with the ATTD of NDF, IDF, and insoluble NSP, indicating that some physical characteristics may influence digestibility of fiber. However, physical characteristics of feed ingredients were not correlated with the concentration of DE and ME, which indicates that these parameters do not influence in vivo energy digestibility in feed ingredients. It is concluded that the DE and ME in feed ingredients may be predicted from some chemical constituents and from in vitro digestibility of DM, but not from physical characteristics.</p

Processing temperature and sugar type affect the rate and the extent of proteolysis of a model soy protein isolate system

Processing of ingredients and diets using hydrothermal treatments can lead to negative effects on the nutritional value of proteins, depending on the processing conditions and the matrix of the ingredient or diet. The aim of this study was to evaluate the effects of processing temperature and sugar type on the extent and rate of protein hydrolysis using soy protein isolate as a model system. The experiment utilized a 3☓3 factorial design, with three repetitions per treatment, using autoclaving temperature (not autoclaved, 100 °C, 120 °C) and type of sugar (not added, glucose, xylose) as main factors, also evaluating the interaction between both. Limited formation of Maillard reaction products occurred in the absence of sugars, whilst the addition of xylose increased the formation of MRPs at all processing temperatures. Crosslinks between amino acids (lysinoalanine, lanthionine) occurred with increasing temperatures, with sugar addition being inhibiting. There was a significant interaction (P < 0.01) between the effects of processing temperature and type of sugar for nitrogen solubility, the extent and rate of proteolysis. The effect of autoclaving at 100°C on the rate of protein hydrolysis of the samples without sugars added was as high as the additional effect of autoclaving after the addition of sugars. In contrast, the effect of autoclaving at 120°C on the rate of protein hydrolysis was higher for the samples that contained sugars, compared to those that did not had sugars added. In conclusion, the effect of sugar addition on the extent and rate of proteolysis seems to be dependent on processing temperature, which might indicate different protein damage mechanisms limiting enzymatic protein hydrolysis.</p

Effects of Toasting Time on Digestive Hydrolysis of Soluble and Insoluble 00-Rapeseed Meal Proteins

Thermal damage to proteins can reduce their nutritional value. The effects of toasting time on the kinetics of hydrolysis, the resulting molecular weight distribution of 00-rapeseed meal (RSM) and the soluble and insoluble protein fractions separated from the RSM were studied. Hydrolysis was performed with pancreatic proteases to represent in vitro protein digestibility. Increasing the toasting time of RSM linearly decreased the rate of protein hydrolysis of RSM and the insoluble protein fractions. The extent of hydrolysis was, on average, 44% higher for the insoluble compared with the soluble protein fraction. In contrast, the rate of protein hydrolysis of the soluble protein fraction was 3–9-fold higher than that of the insoluble protein fraction. The rate of hydrolysis of the insoluble protein fraction linearly decreased by more than 60% when comparing the untoasted to the 120 min toasted RSM. Increasing the toasting time elicited the formation of Maillard reaction products (furosine, Nε-carboxymethyl-lysine and Nε-carboxyethyl-lysine) and disulfide bonds in the insoluble protein fraction, which is proposed to explain the reduction in the hydrolysis rate of this fraction. Overall, longer toasting times increased the size of the peptides resulting after hydrolysis of the RSM and the insoluble protein fraction. The hydrolysis kinetics of the soluble and insoluble protein fractions and the proportion of soluble:insoluble proteins in the RSM explain the reduction in the rate of protein hydrolysis observed in the RSM with increasing toasting time

Real-time modelling of individual weight response to feed supply for fattening pigs

Precision feeding is a promising technique to achieve better feed efficiencies for livestock and realise production results closer to the genetic potential of the animal. Continuous and automatic monitoring of growth of individual finishing pigs is an essential element of a precision feeding system. For optimal pig growth, the feed nutrients need to be adjusted at different moments in time throughout the fattening period. In an integrated system, the key element is the prediction of the process output (weight) to a variation of the process input (feed supply). During the course of this study, three experiments were performed, with 80 pigs on average in each of them, to measure and model their growth responses to step changes in feed amount and/or feed composition along the production cycle. The individual dynamic responses of pig growth to feed changes are monitored by gathering daily weight and feed supply data for each individual pig. The time-series data is analysed using Transfer Function (TF) and Dynamic Linear Regression (DLR) models. On one hand, the average TF model fitting agreement is (RT2=94 ± 4)%. On the other hand, the Mean Relative Prediction Error (MRPE) of applying the DLR approach with a window size of four and seven days was found to be, MRPE = (1.0 ± 0.4)%, and MRPE = (3.3 ± 1.3)% for a forecasting horizon of one and seven days, respectively. Moreover, a parameter of the DLR model resembles the feed efficiency of the pig, exhibiting a coefficient of correlation, r = (0.9 ± 0.2). While the current models may need further validation, the approach seems promising to be implemented in an individual integrated pig feeding system.status: publishe