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

Impact of resistant starch: Absorption of dietary minerals, glycemic index and oxidative stress in healthy rats

BACKGROUND & AIMS

Resistant starch (RS) is a prebiotic fiber that has been scientifically shown to control the development of obesity. Prebiotic role of RS has also seen to be very important as it helps gut bacteria to regulate fermentation and fatty acid production. This study aimed to check the different levels of RS on glycemic index, oxidative stress and mineral absorption rate in healthy rat models. To evaluate these objectives, the trial was conducted for 40 days of follow up; 10 days were the adjustment period and the collection period over 30 days.

METHODS

Thirty-six healthy female Wistar rats were divided into 4 groups of (9 animals each) NC (Normal Control: without resistant starch), RS0.20 (resistant starch: 0.20 g/kg body weight), RS0.30 (resistant starch: 0.30 g/kg body weight), RS0.40 (resistant starch: 0.40 g/kg body weight). All the diets were isocaloric and isonitroginous.

RESULTS

The impact of different levels of RS on the dry-matter intake (DMI) presented statistically significant results (p ≤ 0.05): DMI was reduced in RS (0.02) fed rats as compared to NC rats in first 3 weeks; and after 4th and 5th weeks, there was a DMI reduction of 28% in RS (0.04) fed rats. Moreover, there was no significant increase in the nutrient intake in all RS diets. The dry-matter (DM) digestibility was statistically significantly (P ≤ 0·05), which increased in all rats fed with different level of RS. The weight loss showed statistically significant results: RS (0.04) exhibited 19 g reduction in weight as compared with NC rats. Significant increase was observed in total oxidant status (TOS), in all the RS fed rats when compared with NC rats. The levels of Mg, Ca, Fe and Zn were shown to be decrease in feces analysis, which proves their better absorbance in gut. Statistically significant increase was observed in antioxidant capacity, whereas significant decrease was observed in the total weight of the animals, showing the role of RS in controlling obesity.

CONCLUSIONS

Overall, significant results were found in all dosage level of RS but long term administration of the higher dosage level (RS0.40) may need to be studied for enhanced results. RS can help improve insulin sensitivity in overweight adults.

Resistant starch-enriched brown rice exhibits prebiotic properties and enhances gut health in obese mice

Resistant starch serves as a prebiotic in the large intestine, aiding in the maintenance of a healthy intestinal environment and mitigating associated chronic illnesses. This study aimed to investigate the impact of resistant starch-enriched brown rice (RBR) on intestinal health and functionality. We assessed changes in resistant starch concentration, structural alterations, and branch chain length distribution throughout the digestion process using an in vitro model. The efficacy of RBR in the intestinal environment was evaluated through analyses of its prebiotic potential, effects on intestinal microbiota, and intestinal function-related proteins in obese animals fed a high-fat diet. RBR exhibited a higher yield of insoluble fraction in both the small and large intestines compared to white and brown rice. The total digestible starch content decreased, while the resistant starch content significantly increased during in vitro digestion. Furthermore, RBR notably enhanced the growth of four probiotic strains compared to white and brown rice, displaying higher proliferation activity than the positive control, FOS. Notably, consumption of RBR by high-fat diet-induced obese mice suppressed colon shortening, increased Bifidobacteria growth, and improved intestinal permeability. These findings underscore the potential prebiotic and gut health-promoting attributes of RBR, offering insights for the development of functional foods aimed at preventing gastrointestinal diseases.

Elucidating the modulatory role of dietary hydroxyproline on the integrity and functional performance of the intestinal barrier in early-weaned piglets: A comprehensive analysis of its interplay with the gut microbiota and metabolites

Piglets receive far less hydroxyproline (Hyp) from a diet after weaning than they obtained from sow's milk prior to weaning, suggesting that Hyp may play a protective role in preserving intestinal mucosal homeostasis. This study aimed to evaluate the effect of Hyp on intestinal barrier function and its associated gut microbiota and metabolites in early-weaned piglets. Eighty weaned piglets were divided into four groups and fed diets containing different Hyp levels (0 %, 0.5 %, 1 %, or 2 %) for 21 days. Samples, including intestinal contents, tissues, and blood, were collected on day 7 for analysis of microbial composition, intestinal barrier function, and metabolites. We demonstrated that dietary supplementation with 2 % Hyp improved the feed conversion ratio and reduced the incidence of diarrhea in early-weaned piglets compared to the control group. Concurrently, Hyp enhanced intestinal barrier function by facilitating tight junction protein (zonula occludens (ZO)-1 and occludin) expression and mucin production in the jejunal, ileal, and colonic mucosas. It also improved mucosal immunity (by increasing the amount of secretory IgA (sIgA) and the ratio of CD4+/CD8+ T lymphocytes and decreasing NF-κB phosphorylation) and increased antioxidant capacity (by raising total antioxidant capacity (T-AOC) and glutathione levels) in the intestinal mucosa. In addition, Hyp supplementation resulted in an increase in the levels of glycine, glutathione, and glycine-conjugated bile acids, while decreasing the concentrations of cortisol and methionine sulfoxide in plasma. Intriguingly, piglets fed diet containing Hyp exhibited a remarkable increase in the abundance of probiotic Enterococcus faecium within their colonic contents. This elevation occurred alongside an attenuation of pro-inflammatory responses and an enhancement in intestinal barrier integrity. Further, these changes were accompanied by a rise in anti-inflammatory metabolites, specifically glycochenodeoxycholic acid and guanosine, along with a suppression of pro-inflammatory lipid peroxidation products, including (12Z)-9,10-dihydroxyoctadec-12-enoic acid (9,10-DHOME) and 13-L-hydroperoxylinoleic acid (13(S)-HPODE). In summary, Hyp holds the capacity to enhance the intestinal barrier function in weaned piglets; this effect is correlated with changes in the gut microbiota and metabolites. Our findings provide novel insights into the role of Hyp in maintaining gut homeostasis, highlighting its potential as a dietary supplement for promoting intestinal health in early-weaned piglets.

Structure, properties, and resistant starch content of modified rice flour prepared using dual hydrothermal treatment

In this study, modified rice flour with high resistant starch (RS) content was prepared by dual hydrothermal treatment, which combined the heat-moisture treatment with the pressure-heat treatment method. The effects of dual hydrothermal treatment on the structure and properties of modified rice flour and their relationship with RS content were further discussed. The results showed that the RS content of modified rice flour was higher than that of rice flour (RF), and dual hydrothermal treatment was more effective than single hydrothermal treatment. Adhesion and aggregation occurred between the particles of modified rice flour. Both crystallinity and short-range ordering were increased in modified rice flour compared to RF. Moreover, the modified rice flour of dual hydrothermal treatment had higher crystallinity and a more ordered short-range structure of starch, which improved RS content to a certain extent. Compared to single hydrothermal treatment, the modified rice flour of dual hydrothermal treatment had a lower viscoelasticity and a better thermal stability. Both RF and modified rice flour gels were composed mainly of free water, with minimal amounts of bound and immobile water. The study may provide a reference for the production and application of modified rice flour.

Effects of Resistant Starch Infusion, Solely and Mixed with Xylan or Cellulose, on Gut Microbiota Composition in Ileum-Cannulated Pigs

Fermentation of dietary fiber (DF) is beneficial for gut health, but its prebiotic effects are often impeded in the distal large intestine because of the fast degradation of fermentable substrates. One way to enhance the prebiotic effect of DF is to deliver fibers to the lower parts of the gut, which can be achieved by mixing different kinds of fiber. Therefore, in the present study, an ileum-cannulated pig model was employed to investigate the fermentation influence in the large intestine by infusing resistant starch solely (RS, fast fermentable fiber) and mixing with other fibers (xylan or cellulose). Twenty-four ileum-cannulated growing pigs were divided into four groups: one control group receiving saline ileal infusions and three experimental groups infused with RS, RS with xylan, or RS with cellulose. Fecal and plasma samples were analyzed for gut microbiota composition, short-chain fatty acids (SCFAs), and blood biochemistry. Results indicated no significant differences between the RS and control group for the microbiome and SCFA concentration (p > 0.05). However, RS combined with fibers, particularly xylan, resulted in enhanced and prolonged fermentation, marked by an increase in Blautia and higher lactate and acetate production (p < 0.05). In contrast, RS with cellulose infusion enriched bacterial diversity in feces (p < 0.05). Blood biochemistry parameters showed no significant differences across groups (p > 0.05), though a trend of increased glucose levels was noted in the treatment groups (p < 0.1). Overall, RS alone had a limited impact on the distal hindgut microbiota due to rapid fermentation in the proximal gut, whereas combining RS with other fibers notably improved gut microecology by extending the fermentation process.

Carbohydrases and Phytase in Poultry and Pig Nutrition: A Review beyond the Nutrients and Energy Matrix

This review aimed to clarify the mechanisms through which exogenous enzymes (carbohydrases and phytase) influence intestinal health, as well as their effects on the nutrients and energy matrix in diets fed to poultry and pigs reared under sanitary challenging conditions. Enzyme supplementation can positively affect intestinal microbiota, immune system, and enhance antioxidant status. Although enzymes have been shown to save energy and nutrients, their responses under sanitary challenging conditions are poorly documented. Immune system activation alters nutrient partitioning, which can affect the matrix values for exogenous enzymes on commercial farms. Notably, the carbohydrases and phytase supplementation under sanitary challenging conditions align with energy and nutritional valorization matrices. Studies conducted under commercial conditions have shown that matrices containing carbohydrases and phytase can maintain growth performance and health in poultry and pigs. However, these studies have predominantly focused on assessing a single level of reduction in energy and/or available phosphorus and total calcium, limiting our ability to quantify potential energy and nutrient savings in the diet. Future research should delve deeper into determining the extent of energy and nutrient savings and understanding the effects of alone or blended enzymes supplementation to achieve more specific insights.

Oregano Essential Oil and Purple Garlic Powder Effects on Intestinal Health, Microbiota Indicators and Antimicrobial Resistance as Feed Additives in Weaning Piglets

Finding alternatives to zinc oxide is a pressing issue for the pig production sector. We studied the impact of the bioactive components degradation of oregano essential oil (OEO) and purple garlic powder (PGP) during storage in silos, their effect on the morphometry of the jejunum and ileum and the cecal microbiota as intestinal health indicators in piglets during the post-weaning period. We also monitored antimicrobial resistance in the commensal indicator E. coli. Histological parameters and intestinal microbiota were measured in 140 piglets weaned at 21 days of age. Seven dietary treatments were used: a negative control group (basal diet), a positive control group with ZnO (3000 mg/kg of food), two groups with OEO at 0.4% and 1.2%, respectively, two groups with PGP 0.4% and 2%, respectively, and a group with OEO with 1.2% combined with PGP with 2%. Each group of piglets received the treatment for seven weeks, from weaning, before samples were taken. Antibiotic resistance profiles were measured in 81 E. coli strains. On this occasion, only the control groups, ZnO, OEO 1.2%, PGP 2% and OEO 1.2% + PGP 2% were used, and the samples were obtained from the cecal content. A progressive loss of the bioactive components of OEO and PGP was observed during the 34 days of storage (p < 0.05). PGP 2%, OEO 1.2% and their combination showed results similar to ZnO (p > 0.05), or superior in the study of intestinal morphometry and the values of E. coli and Lactobacillus. All categories showed high levels of resistance. Only the strains isolated from the OEO 1.2% group did not show resistance to colistin and presented the lowest resistance values. In general, high doses of the additives studied showed the best results, obtaining levels like or higher than those offered by ZnO.

Type 2-resistant starch and Lactiplantibacillus plantarum NCIMB 8826 result in additive and interactive effects in diet-induced obese mice

Little is known about how combining a probiotic with prebiotic dietary fiber affects the ability of either biotic to improve health. We hypothesized that prebiotic, high-amylose maize type 2-resistant starch (RS) together with probiotic Lactiplantibacillus plantarum NCIMB8826 (LP) as a complementary synbiotic results in additive effects on the gut microbiota in diet-induced obese mice and other body sites. Diet-induced obese C57BL/6J male mice were fed a high-fat diet adjusted to contain RS (20% by weight), LP (109 cells every 48 hours), or both (RS+LP) for 6 weeks. As found for mice fed RS, cecal bacterial alpha diversity was significantly reduced in mice given RS+LP compared with those fed LP and high-fat controls. Similarly, both RS+LP and RS also conferred lower quantities of cecal butyrate and serum histidine and higher ileal TLR2 transcript levels and adipose tissue interleukin-6 protein. As found for mice fed LP, RS+LP-fed mice had higher colonic tissue TH17 cytokines, reduced epididymal fat immune and oxidative stress responses, reduced serum carnitine levels, and increased transcript quantities of hepatic carnitine palmitoyl transferase 1α. Notably, compared with RS and LP consumed separately, there were also synergistic increases in colonic glucose and hepatic amino acids as well antagonistic effects of LP on RS-mediated increases in serum adiponectin and urinary toxin levels. Our findings show that it is not possible to fully predict outcomes of synbiotic applications based on findings of the probiotic or the prebiotic tested separately; therefore, studies should be conducted to test new synbiotic formulations.

The Effect of Prebiotic Supplements on the Gastrointestinal Microbiota and Associated Health Parameters in Pigs

Establishing a balanced and diverse microbiota in the GIT of pigs is crucial for optimizing health and performance throughout the production cycle. The post-weaning period is a critical phase, as it is often associated with dysbiosis, intestinal dysfunction and poor performance. Traditionally, intestinal dysfunctions associated with weaning have been alleviated using antibiotics and/or antimicrobials. However, increasing concerns regarding the prevalence of antimicrobial-resistant bacteria has prompted an industry-wide drive towards identifying natural sustainable dietary alternatives. Modulating the microbiota through dietary intervention can improve animal health by increasing the production of health-promoting metabolites associated with the improved microbiota, while limiting the establishment and proliferation of pathogenic bacteria. Prebiotics are a class of bioactive compounds that resist digestion by gastrointestinal enzymes, but which can still be utilized by beneficial microbes within the GIT. Prebiotics are a substrate for these beneficial microbes and therefore enhance their proliferation and abundance, leading to the increased production of health-promoting metabolites and suppression of pathogenic proliferation in the GIT. There are a vast range of prebiotics, including carbohydrates such as non-digestible oligosaccharides, beta-glucans, resistant starch, and inulin. Furthermore, the definition of a prebiotic has recently expanded to include novel prebiotics such as peptides and amino acids. A novel class of -biotics, referred to as "stimbiotics", was recently suggested. This bioactive group has microbiota-modulating capabilities and promotes increases in short-chain fatty acid (SCFA) production in a disproportionally greater manner than if they were merely substrates for bacterial fermentation. The aim of this review is to characterize the different prebiotics, detail the current understating of stimbiotics, and outline how supplementation to pigs at different stages of development and production can potentially modulate the GIT microbiota and subsequently improve the health and performance of animals.

Maternal Supplementation of Vitamin E or Its Combination with Hydroxytyrosol Increases the Gut Health and Short Chain Fatty Acids of Piglets at Weaning

An adequate intestinal environment before weaning may contribute to diarrhea predisposition and piglet development. This study evaluates how the dietary supplementation of vitamin E (VE) (100 mg/kg), hydroxytyrosol (HXT) (1.5 mg/kg) or the combined administration (VE + HXT) given to Iberian sows from gestation affects the piglet's faecal characteristics, short chain fatty acids (SCFAs), fatty acid profile or intestinal morphology as indicators of gut health; and quantify the contribution of the oxidative status and colostrum/milk composition to the piglet's SCFAs content and intestinal health. Dietary VE increased isobutyric acid (iC4), butyric acid (C4), isovaleric acid (iC5), and ∑SCFAs, whereas HXT increased iC4 and tended to decrease ∑SCFAs of faeces. Piglets from HXT-supplemented sows also tended to have higher faecal C20:4n-6/C20:2 ratio C22:6 proportion and showed lower occludin gene expression in the duodenum. The combination of both antioxidants had a positive effect on iC4 and iC5 levels. Correlation analyses and regression equations indicate that faecal SCFAs were related to oxidative status (mainly plasma VE) and colostrum and milk composition (mainly C20:2, C20:3, C20:4 n-6). This study would confirm the superiority of VE over HXT supplementation to improve intestinal homeostasis, gut health, and, consequently piglet growth.

Combined effect of microbially derived cecal SCFA and host genetics on feed efficiency in broiler chickens

BACKGROUND

Improving feed efficiency is the most important goal for modern animal production. The regulatory mechanisms of controlling feed efficiency traits are extremely complex and include the functions related to host genetics and gut microbiota. Short-chain fatty acids (SCFAs), as significant metabolites of microbiota, could be used to refine the combined effect of host genetics and gut microbiota. However, the association of SCFAs with the gut microbiota and host genetics for regulating feed efficiency is far from understood.

RESULTS

In this study, 464 broilers were housed for RFI measuring and examining the host genome sequence. And 300 broilers were examined for cecal microbial data and SCFA concentration. Genome-wide association studies (GWAS) showed that four out of seven SCFAs had significant associations with genome variants. One locus (chr4: 29414391-29417189), located near or inside the genes MAML3, SETD7, and MGST2, was significantly associated with propionate and had a modest effect on feed efficiency traits and the microbiota. The genetic effect of the top SNP explained 8.43% variance of propionate. Individuals with genotype AA had significantly different propionate concentrations (0.074 vs. 0.131 μg/mg), feed efficiency (FCR: 1.658 vs. 1.685), and relative abundance of 14 taxa compared to those with the GG genotype. Christensenellaceae and Christensenellaceae_R-7_group were associated with feed efficiency, propionate concentration, the top SNP genotypes, and lipid metabolism. Individuals with a higher cecal abundance of these taxa showed better feed efficiency and lower concentrations of caecal SCFAs.

CONCLUSION

Our study provides strong evidence of the pathway that host genome variants affect the cecal SCFA by influencing caecal microbiota and then regulating feed efficiency. The cecal taxa Christensenellaceae and Christensenellaceae_R-7_group were identified as representative taxa contributing to the combined effect of host genetics and SCFAs on chicken feed efficiency. These findings provided strong evidence of the combined effect of host genetics and gut microbial SCFAs in regulating feed efficiency traits. Video Abstract.

Avocado seed starch: Effect of the variety on molecular, physicochemical, and digestibility characteristics

Agro-industrial residues can increase environmental pollution owing to poor knowledge of the use of some components, such as dietary fiber, protein, starch, minerals, and bioactive compounds, which can be used in the food industry. This study compared the molecular, physicochemical, and digestibility characteristics of three avocado seed starches (Criolla, Fuerte, and Hass). Starch was extracted through successive washing and sedimentation. The morphology, size distribution, thermal properties, pasting properties, infrared spectra with Fourier transform, size distribution of amylopectin chains, and digestibility of the three avocado seed strains were analyzed. The starch grains were oval and spherical in shape. The average size of Criolla avocado starch (24.55 μm) was the largest, followed by Hass and Fuerte starches (21.37 μm). Higher gelatinization enthalpy (8.55 J/g), gelatinization temperature (75.28 °C), and pasting temperature (75.57 °C) were observed for Fuerte avocado starch, followed by Hass and Criolla starches. Hass avocado starch exhibited higher maximum (836.27 mPa.s), final (1407.37 mPa.s), setback (588.78 mPa.s), and breakdown (17.68 mPa.s) viscosities than Criolla and Fuerte avocado starches. In addition, the probed avocado starches exhibited high content of resistant starch (60.06-68.90%). Therefore, it was demonstrated that differences in the chemical composition and structure of avocado starch can affect the digestibility of native starch.

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.

Changes in the physicochemical properties of isolated starch and plantain (Musa AAB Simmonds) flours for early maturity stage

This work focuses on the study of the physicochemical changes that take place during the first stage of ripening of plantain, with particular attention to the changes in the orthorhombic and hexagonal nanocrystals present in this starch, and its relation shift with resistance starch. Significant changes were observed in the proximal analysis of plantain flour. A gradual increase in moisture content was attributed to the high content of crystalline structures and molecules that can be removed by drying. Water activity increased with ripening, which was attributed to the hygroscopic nature of the flours. The protein content increased, and the carbohydrate content decreased, indicating the progress of biochemical reactions. The changes in the fat content are consistent with the hydrolysis and resynthesis of lipids during the ripening process. The obtained results indicate a significant influence of the ripening stage on the physicochemical properties of flour and starch of plantain, which is associated with the occurrence of a climacteric peak on the 4th day of ripening. The hydration properties of plantain flour decreased significantly during the ripening days, consistent with the occurrence of a climacteric peak. Water holding capacity (WHC) and water binding capacity (WBC) were affected by the degree of digestion of native starch granules and protein denaturation during fruit ripening. Scanning electron microscopes (SEM) showed that during ripening the surface of the isolated starches do not suffer any significative damage. X-ray diffraction patterns were used to identify crystalline structures and to study the changes in the crystalline structures. These results showed that the starch contains orthorhombic and hexagonal nanocrystals, which play and important role and which show small structural damage during ripening reflected in a decrease in their relative crystallinity. This is the first time that these nanocrystals have been studied and considered in the ripening process. Differential scanning calorimetry was used to study the thermal transition in isolated starch. The results indicated that the gelatinization of starch corresponds to the solvation of orthorhombic and hexagonal nanocrystals, and that during ripening there is a decrease in the enthalpy reflecting some crystal structural damage. Pasting properties were studied using a Starch cell for flours and isolated starches, indicating that the pasting profile is governed by intrinsic and extrinsic factors. The resistant starch does not show significant changes at this stage of maturation. This starch is the one with the highest resistant starch content reported in the literature (38%). It was hypothesized that the resistant starch is directly related to the amount of whole starch granules, and more importantly, directly related to the number concentration of orthorhombic and hexagonal nanocrystals. Therefore, knowledge of the physicochemical and nutritional properties of plantain and flour at each stage of ripening allows better selection according to industrial applications.

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.

Microbial Interventions to Improve Neonatal Gut Health

The diverse pioneer microbial community colonizing the mammalian gastrointestinal tract is critical for the developing immune system. Gut microbial communities of neonates can be affected by various internal and external factors, resulting in microbial dysbiosis. Microbial dysbiosis during early life affects gut homeostasis by changing metabolic, physiological, and immunological status, which increases susceptibility to neonatal infections and long-term pathologies. Early life is crucial for the establishment of microbiota and the development of the host immune system. Therefore, it provides a window of opportunity to reverse microbial dysbiosis with a positive impact on host health. Recent attempts to use microbial interventions during early life have successfully reversed dysbiotic gut microbial communities in neonates. However, interventions with persistent effects on microbiota and host health are still limited. This review will critically discuss microbial interventions, modulatory mechanisms, their limitations, and gaps in knowledge to understand their roles in improving neonatal gut health.

Effects of Consuming Heat-Treated Dodamssal Brown Rice Containing Resistant Starch on Glucose Metabolism in Humans

Rice is a major source of carbohydrates. Resistant starch (RS) is digested in the human small intestine but fermented in the large intestine. This study investigated the effect of consuming heat-treated and powdered brown rice cultivars 'Dodamssal' (HBD) and 'Ilmi' (HBI), with relatively high and less than 1% RS content, respectively, on the regulation of glucose metabolism in humans. Clinical trial meals were prepared by adding ~80% HBI or HBD powder to HBI and HBD meals, respectively. There was no statistical difference for protein, dietary fiber, and carbohydrate content, but the median particle diameter was significantly lower in HBI meals than in HBD meals. The RS content of HBD meals was 11.4 ± 0.1%, and the HBD meals also exhibited a low expected glycemic index. In a human clinical trial enrolling 36 obese participants, the homeostasis model assessment for insulin resistance decreased by 0.05 ± 0.14% and 1.5 ± 1.40% after 2 weeks (p = 0.021) in participants in the HBI and HBD groups, respectively. The advanced glycation end-product increased by 0.14 ± 0.18% in the HBI group and decreased by 0.06 ± 0.14% in the HBD group (p = 0.003). In conclusion, RS supplementation for 2 weeks appears to have a beneficial effect on glycemic control in obese participants.

Gut Health and Influencing Factors in Pigs

The gastrointestinal tract (GIT) is a complex, dynamic, and critical part of the body, which plays an important role in the digestion and absorption of ingested nutrients and excreting waste products of digestion. In addition, GIT also plays a vital role in preventing the entry of harmful substances and potential pathogens into the bloodstream. The gastrointestinal tract hosts a significant number of microbes, which throughout their metabolites, directly interact with the hosts. In modern intensive animal farming, many factors can disrupt GIT functions. As dietary nutrients and biologically active substances play important roles in maintaining homeostasis and eubiosis in the GIT, this review aims to summarize the current status of our knowledge on the most important areas.

The Interplay of Dietary Fibers and Intestinal Microbiota Affects Type 2 Diabetes by Generating Short-Chain Fatty Acids

Foods contain dietary fibers which can be classified into soluble and insoluble forms. The nutritional composition of fast foods is considered unhealthy because it negatively affects the production of short-chain fatty acids (SCFAs). Dietary fiber is resistant to digestive enzymes in the gut, which modulates the anaerobic intestinal microbiota (AIM) and fabricates SCFAs. Acetate, butyrate, and propionate are dominant in the gut and are generated via Wood-Ljungdahl and acrylate pathways. In pancreatic dysfunction, the release of insulin/glucagon is impaired, leading to hyperglycemia. SCFAs enhance insulin sensitivity or secretion, beta-cell function, leptin release, mitochondrial function, and intestinal gluconeogenesis in human organs, which positively affects type 2 diabetes (T2D). Research models have shown that SCFAs either enhance the release of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) from L-cells (entero-endocrine), or promotes the release of leptin hormone in adipose tissues through G-protein receptors GPR-41 and GPR-43. Dietary fiber is a component that influences the production of SCFAs by AIM, which may have beneficial effects on T2D. This review focuses on the effectiveness of dietary fiber in producing SCFAs in the colon by the AIM as well as the health-promoting effects on T2D.

Dietary Supplementation of Eubiotic Fiber Based on Lignocellulose on Performance and Welfare of Gestating and Lactating Sows

The present study aimed to evaluate the effects of partially fermentable insoluble dietary fiber supplementation on the behavior, surface temperature, and reproductive parameters of gestating and lactating sows, as well as on the performance of their litters. Four hundred hyper-prolific sows were assigned in a randomized block design with two treatment groups during the gestation phase: Control (C), corn-soy based diets, or corn-soy based diets with daily 55 g supplementation of eubiotic fiber (F) from the 85th day of gestation until the farrowing (late pregnancy). During the lactation phase, the sows were assigned in a 2 × 2 factorial design using the following treatment groups: (1) CC, no fiber included during gestation and lactation. (2) FC, daily inclusion of 55 g of fiber only during late pregnancy. (3) CF, daily inclusion of 55 g of fiber only during lactation. (4) FF, daily inclusion of 55 g of fiber during late pregnancy and lactation. Sows that received dietary fiber supplementation during the final third of gestation increased feed intake during lactation. Piglets from sows supplemented in both phases showed a significant increase in weight at weaning. The dietary supplementation of eubiotic fiber for sows in the end period of gestation and lactation improved performance and welfare, with positive consequences for developing their litters.

A low-carbon high inulin diet improves intestinal mucosal barrier function and immunity against infectious diseases in goats

Introduction

Abrupt weaning is a major stressful event, contributing to intestinal abnormalities and immune system dysfunction in weaned kids. Inulin is a prebiotic fiber with many positive functions, including promoting intestinal fermentation and enhancing host immunity in monogastric animals. However, the effects of a high-inulin, energy-rich diet on ruminal fermentation characteristics, methane emission, growth performance, and immune systems of weaned kids have not been investigated.

Methods

A fully automated in vitro fermentation system was used to investigate ruminal fermentation characteristics and methane emission of a mixed substrate of inulin and fat powder (1.31: 1) in comparison with maize grain-based starter concentrate. During a 1-week adaptation and 4-week trial phase, 18 weaned kids (8.97 ± 0.19 kg) were randomly assigned to two groups, one with a conventional diet (83% maize grain; CON) and the other with a low-carbon, high-inulin diet (41.5% maize grain, 14.4% fat powder, 18.9% inulin; INU).

Results

In the in vitro rumen fermentation experiment, the total gas production was not different (p > 0.05); however, a lower (p < 0.05) methane production was observed for INU as compared to CON. The average daily gain and the ratio of feed intake and growth performance of kids fed with INU were higher (p < 0.05) than those fed with CON. Serum concentrations of alanine transaminase (ALT) and lactate dehydrogenase (LDH) were lower (p < 0.05), whereas the concentration of high-density lipoprotein (HDL) and cholesterol (CHOL) were higher (p < 0.05) in kids fed with the INU diet as compared CON. Dietary inulin significantly increased (p < 0.05) the secretion of immunoglobulins (IgA, IgG, and IgM) and inflammatory cytokines (IFN-γ and IL-10) in ileum tissue. Although no differences (p > 0.05) were observed in mRNA expression of tight junction markers, the INU diet tended to increase (p = 0.09) gene expression of ribosomal protein S6 kinase beta-1 (P70S6K) in the mammalian target of rapamycin (mTOR) pathway of longissimus dorsi muscle.

Conclusion

Our findings highlighted that a low-carbon high-inulin energy-rich diet could be used as a promising strategy to improve gut immunity and growth performance of weaned kids under abrupt weaning stress and reduce methane production.

The improvement of parturition duration by high intake of dietary fibre in late gestation is associated with gut microbiota and metabolome in sows

Prolonged parturition duration has been widely demonstrated to be a risk factor for incidence of stillbirth. This study evaluated the supply of dietary fibre on the parturition duration, gut microbiota and metabolome using sows as a model. A total of 40 Yorkshire sows were randomly given diet containing normal level of dietary fibre (NDF, 17·5 % dietary fibre) or high level of dietary fibre (HDF, 33·5 % dietary fibre). Faecal microbiota profiled with 16S rRNA amplicon sequencing, SCFA and metabolome in the faeces and plasma around parturition were compared between the dietary groups. Correlation analysis was conducted to further explore the potential associations between specific bacterial taxa and metabolites. Results showed that HDF diet significantly improved the parturition process as presented by the shorter parturition duration. HDF diet increased the abundance of the phyla Bacteroidetes and Synergistetes and multiple genera. Except for butyrate, SCFA levels in the faeces and plasma of sows at parturition were elevated in HDF group. The abundances of fifteen and twelve metabolites in the faeces and plasma, respectively, markedly differ between HDF and NDF sows. These metabolites are involved in energy metabolism and bacterial metabolism. Correlation analysis also showed associations between specific bacteria taxa and metabolites. Collectively, our study indicates that the improvement of parturition duration by high fibre intake in late gestation is associated with gut microbiota, production of SCFA and other metabolites, potentially serving for energy metabolism.

Phenolic profile, alpha-amylase inhibitory activity, and in vitro glycemic index of adzuki beans

Regular consumption of low-glycemic index (GI) foods is a common strategy for type 2 diabetes patients. To evaluate the potential application of adzuki beans in low-GI foods, the phenolic profile and alpha-amylase inhibitor (α-AI) activity of four varieties of adzuki beans (G24, Te Xiao Li No. 1, Gui Nong No. 1, and Qian Xiao Hei) were determined. The starch digestibility properties and in vitro glycemic index (IVGI) of these beans were also evaluated using the in vitro digestion model coupled with 3,5-dinitrosalicylic acid colorimetry. The results indicated that these adzuki beans, containing numerous phenolics, showed inhibitory activities to alpha-amylase with the α-AI activities between 1.760 ± 0.044 and 3.411 ± 0.186 U/g. The resistant starch (RS) contributed predominantly to the total starch with proportions between (69.78 ± 2.45%) and (81.03 ± 0.06%); Te Xiao Li No. 1 was the highest compared with the other varieties. The adzuki beans were categorized into low- or medium-GI foods, and the IVGI ranged from (39.00 ± 0.36) to (56.76 ± 4.21). These results suggested that adzuki beans can be used as a component of low-GI foods.

Long-term chemically protected sodium butyrate supplementation in broilers as an antibiotic alternative to dynamically modulate gut microbiota

Chemically protected sodium butyrate (CSB) is a new kind of sodium butyrate. Our previous study found that 1,000 mg/kg of CSB had the potential capacity of improving growth performance and promoting early development of small intestine in broilers. This study aimed to investigate the effect of long-term antibiotics or CSB supplementation for intestinal microflora dynamical regulation in broilers. One hundred ninety-two 1-day-old Arbor Acres male broilers were randomly allocated into 3 dietary treatment (8 replicates per treatment) and fed with a basal diet (CON), a diet supplemented with the antibiotics (enramycin, 8 mg/kg and aureomycin, 100 mg/kg) (ANT), or a diet supplemented with 1,000 mg/kg of CSB, respectively. Results showed that dietary supplementation of CSB or ANT treatment elevated the weight gain and feed conversion ratio (FCR; P < 0.05), as compared with control (CON) group. Additionally, CON, CSB, or ANT administration dynamically altered the gut microbiota composition as time goes on. The increased presence of potential pathogens, such as Romboutsia and Shuttleworthia, and decreased beneficial bacteria such as Alistipes, Akkermansia, and Bacteroides were verified in new gut homeostasis reshaped by long-term antibiotics treatment, which has adverse effects on intestinal development and health of broilers. Conversely, CSB supplementation could dynamically enhance the relative abundance of Bacteroides, and decrease Romboutsia and Shuttleworthia in new microflora, which has positive effects on intestinal bacteria of broilers compared with CON group. Meanwhile, CSB supplementation was significantly increased the concentration of propionic acid and total short chain fatty acids (total SCFA; P < 0.05) in comparison with CON and ANT groups. Moreover, CSB treatment significantly increased anti-inflammatory and antioxidative capacities (P < 0.05) of broilers compared with ANT group. Taken together, we revealed characteristic structural changes of gut microbiota throughout long-term CSB or ANT supplementation in broilers, which provided a basic data for evaluating the mechanism of action affecting intestinal health by CSB or ANT administration and CSB as an alternative to antibiotics in the broilers industry.

Uncovering the biogeography of the microbial commmunity and its association with nutrient metabolism in the intestinal tract using a pig model

The gut microbiota is a complex ecosystem that is essential for the metabolism, immunity and health of the host. The gut microbiota also plays a critical role in nutrient absorption and metabolism, and nutrients can influence the growth and composition of the gut microbiota. To gain a better understanding of the relationship between the gut microbial composition and nutrient metabolism, we used a pig model by collecting the contents of the different intestinal locations from six pigs to investigate microbial composition in different intestinal locations based on 16S rRNA gene sequencing and the concentrations of short-chain fatty acids (SCFAs), amino acids, fat, and crude ash in different intestinal locations using gas chromatography and chemical analysis. The results showed that the richness and diversity of intestinal microbial communities gradually increased from the small intestine to the large intestine. The relative abundance of Proteobacteria was higher in the jejunum and ileum, whereas the proportion of Firmicutes was higher in the cecum and colon. The concentrations of SCFAs were higher in the cecum and colon (P < 0.05). The concentrations of amino acids were higher in the small intestine than in the large intestine, while the amino acid content was significantly higher in the ascending colon than in the transverse colon and descending colon. The correlation analysis revealed that Ruminococcaceae UCG-005, Coriobacteriaceae_uncultured, [Eubacterium] hallii group, Mogibacterium and Lachnospiraceae AC2044 group had a higher positive correlation with SCFAs, crude ash and fat but had a negative correlation with amino acids in different gut locations of pigs. These findings may serve as fundamental data for using nutrient metabolism to regulate human and animal gut microbes and health and provide guidance for exploring host-microbe bidirectional interaction mechanisms and driving pathways.

Mucin O-glycan-microbiota axis orchestrates gut homeostasis in a diarrheal pig model

BACKGROUND

Post-weaning diarrhea in piglets reduces growth performance and increases mortality, thereby causing serious economic losses. The intestinal epithelial cells and microbiota reciprocally regulate each other in order to maintain intestinal homeostasis and control inflammation. However, a relative paucity of research has been focused on the host-derived regulatory network that controls mucin O-glycans and thereby changes gut microbiota during diarrhea in infancy. At the development stage just after birth, the ontogeny of intestinal epithelium, immune system, and gut microbiota appear similar in piglets and human infants. Here, we investigated the changes of mucin O-glycans associated with gut microbiota using a diarrheal post-weaned piglet model.

RESULTS

We found that diarrhea disrupted the colonic mucus layer and caused aberrant mucin O-glycans, including reduced acidic glycans and truncated glycans, leading to an impaired gut microenvironment. Subsequently, the onset of diarrhea, changes in microbiota and bacterial translocation, resulting in compromised epithelial barrier integrity, enhanced susceptibility to inflammation, and mild growth faltering. Furthermore, we found the activation of NLRP3 inflammasome complexes in the diarrheal piglets when compared to the healthy counterparts, triggered the release of proinflammatory cytokines IL-1β and IL-18, and diminished autophagosome formation, specifically the defective conversion of LC3A/B I into LC3A/B II and the accumulation of p62. Additionally, selective blocking of the autophagy pathway by 3-MA led to the reduction in goblet cell-specific gene transcript levels in vitro.

CONCLUSIONS

We observed that diarrheal piglets exhibited colonic microbiota dysbiosis and mucosal barrier dysfunction. Our data demonstrated that diarrhea resulted in the activation of inflammasomes and autophagy restriction along with aberrant mucin O-glycans including reduced acidic glycans and truncated glycans. The results suggested the mucin O-glycans-microbiota axis is likely associated with diarrheal pathogenesis. Our study provides novel insights into the pathophysiology of early-weaning-induced diarrheal disease in piglets and potentially understanding of disease mechanisms of diarrhea for human infants. Understanding the molecular pathology and pathogenesis of diarrhea is a prerequisite for the development of novel and effective therapies. Our data suggest that facilitating O-glycan elongation, modifying the microbiota, and developing specific inhibitors to some key inflammasomes could be the options for therapy of diarrhea including human infants. Video abstract.

The regulatory function of Blastocystis spp. on the immune inflammatory response in the gut microbiome

Blastocystis spp. is a unicellular organism that resides in digestive tract of various vertebrates, with a worldwide distribution and a variable prevalence. For many years, Blastocystis spp. was considered a cyst of a flagellate, a fungus, or a saprophyte yeast of the digestive tract; in 1996, it is placed in the group of stramenopiles (heterokonts). Since its new classification, many questions have arisen around this protist about its role as a pathogen or non-pathogen organism. Recent evidence indicates that Blastocystis spp. participates in the immune inflammatory response in the intestinal microbiome generating an anti-inflammatory response, showing a lower concentration of fecal inflammatory markers in infected human hosts. Here, we review recent findings on the regulatory function of Blastocystis spp. in the immune inflammatory response to comprehend the purpose of Blastocystis spp. in health and disease, defining if Blastocystis spp. is really a pathogen, a commensal or even a mutualist in the human gut microbiome.

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.

Invited review: strategic adoption of antibiotic-free pork production: the importance of a holistic approach

The discovery of the use of antibiotics to enhance growth in the 1950s proved to be one of the most dramatic and influential in the history of animal agriculture. Antibiotics have served animal agriculture, as well as human and animal medicine, well for more than seven decades, but emerging from this tremendous success has been the phenomenon of antimicrobial resistance. Consequently, human medicine and animal agriculture are being called upon, through legislation and/or marketplace demands, to reduce or eliminate antibiotics as growth promotants and even as therapeutics. As explained in this review, adoption of antibiotic-free (ABF) pork production would represent a sea change. By identifying key areas requiring attention, the clear message of this review is that success with ABF production, also referred to as "no antibiotics ever," demands a multifaceted and multidisciplinary approach. Too frequently, the topic has been approached in a piecemeal fashion by considering only one aspect of production, such as the use of certain feed additives or the adjustment in health management. Based on the literature and on practical experience, a more holistic approach is essential. It will require the modification of diet formulations to not only provide essential nutrients and energy, but to also maximize the effectiveness of normal immunological and physiological capabilities that support good health. It must also include the selection of effective non-antibiotic feed additives along with functional ingredients that have been shown to improve the utility and architecture of the gastrointestinal tract, to improve the microbiome, and to support the immune system. This holistic approach will require refining animal management strategies, including selection for more robust genetics, greater focus on care during the particularly sensitive perinatal and post-weaning periods, and practices that minimize social and environmental stressors. A clear strategy is needed to reduce pathogen load in the barn, such as greater emphasis on hygiene and biosecurity, adoption of a strategic vaccine program and the universal adoption of all-in-all-out housing. Of course, overall health management of the herd, as well as the details of animal flows, cannot be ignored. These management areas will support the basic biology of the pig in avoiding or, where necessary, overcoming pathogen challenges without the need for antibiotics, or at least with reduced usage.

Immunotherapy and Microbiota for Targeting of Liver Tumor-Initiating Stem-like Cells

Cancer contains tumor-initiating stem-like cells (TICs) that are resistant to therapies. Hepatocellular carcinoma (HCC) incidence has increased twice over the past few decades, while the incidence of other cancer types has trended downward globally. Therefore, an understanding of HCC development and therapy resistance mechanisms is needed for this incurable malignancy. This review article describes links between immunotherapies and microbiota in tumor-initiating stem-like cells (TICs), which have stem cell characteristics with self-renewal ability and express pluripotency transcription factors such as NANOG, SOX2, and OCT4. This review discusses (1) how immunotherapies fail and (2) how gut dysbiosis inhibits immunotherapy efficacy. Gut dysbiosis promotes resistance to immunotherapies by breaking gut immune tolerance and activating suppressor immune cells. Unfortunately, this leads to incurable recurrence/metastasis development. Personalized medicine approaches targeting these mechanisms of TIC/metastasis-initiating cells are emerging targets for HCC immunotherapy and microbiota modulation therapy.

Chemical Components, Antioxidant Activity, and Glycemic Response Values of Purple Sweet Potato Products

Purple sweet potato is a source of starch with high potential to be developed as a functional food. It can be boiled and consumed as a snack or processed into intermediate goods such as flour. The flour can then be modified through partial gelatinization and followed by a retrogradation process to produce resistant starch-rich purple sweet potato flour. The study was aimed at obtaining the glycemic response values of purple sweet potato products, namely, boiled purple sweet potatoes (BSP), purple sweet potato noodles (SPN), and resistant starch-rich purple sweet potato noodles (RSPN). SPN was prepared from conventional purple sweet potato flour, whereas RSPN was made from resistant starch-rich purple sweet potato flour. Moreover, water, ash, protein, fat, and carbohydrate; total phenolic, anthocyanin, and resistant starch contents; and the rate of hydrolysis of starch were evaluated. Ten subjects were involved in the estimation of glycemic response determined by the area under the curve (AUC) of the blood glucose after consuming products. Glucose syrup was used as a reference. The glycemic response data were processed using ANOVA and further tested using LSD at p < 0.05. The results showed RSPN had the lowest glycemic index value if compared to BSP and SPN (58.7, 63.5, and 83.7) and fell under food with medium GI, but the differences were not statistically significant. RSPN and SPN were classified as medium GI; however, the process of partial gelatinization followed by retrogradation during the preparation of flour used for raw material in making RSPN has successfully maintained the total phenol and anthocyanin and increased resistant starch content of the noodle Processing of purple sweet potato flour into noodle lowered the GI category, and when the flour was partially gelatinized and retrograded, the noodle had more potentiality as a functional food due to their high total phenolic and anthocyanin content.

Extruded Enzyme-Added Corn Improves the Growth Performance, Intestinal Function, and Microbiome of Weaning Piglets

The objective of this study was to evaluate the effects of extruded corn with added amylase under different moisture conditions on the growth performance, intestinal function, and microbiome of weaning piglets. Fourty-eight 24-day-old weaning piglets (Duroc × Landrace × Yorkshire, weaned at 22 ± 1 d) with an initial body weight of 6.76 ± 0.15 kg were randomly assigned to one of four dietary treatments with six replicates per treatment and two pigs per replicate: (1) NL (adding 7.5% water before corn extrusion, negative treatment with low moisture); (2) NH (adding 15.0% water before corn extrusion, negative treatment with high moisture); (3) PL (adding 7.5% water and 4 kg/t α-amylase before corn extrusion, positive treatment with low moisture); and (4) PH (adding 15% water and 4 kg/t α-amylase before corn extrusion, positive treatment with high moisture). Results showed that amylase supplementation (4 vs. 0 kg/t) increased the contents of small molecular oligosaccharides of extruded corn (p < 0.05). Amylase supplementation significantly improved the average daily feed intake, apparent total tract digestibility (ATTD) of dry matter, crude protein, gross energy, crude fat, ash, phosphorus, and calcium, and also increased the activities of jejunal trypsin, α-amylase, lipase, sucrase, maltase, γ-glutamyl transferase and alkaline phosphatase activities, improved the duodenal, jejunal and ileal morphology, and increased the relative mRNA expressions of the ZO-1, OCLN, SGLT1, and GLUT2 genes in the jejunum (p < 0.05), whereas it decreased the contents of isobutyric acid in cecal digesta, as well as acetic acid and isobutyric acid in colonic digesta (p < 0.05). Moreover, the linear discriminant analysis effect size (LEfSe) showed that piglets fed extruded corn with added enzymes contained less intestinal pathogenic bacteria, such as Holdemanella and Desulfovibrio, compared with piglets fed just extruded corn. In summary, the results of the present study indicated that the supplementation of α-amylase during the conditioning and extruding process of corn increased the small molecular oligosaccharide content of corn starch. Moreover, piglets receiving extruded enzyme-added corn had better growth performance, which was associated with the improved intestinal digestive and absorptive function, as well as the intestinal microbiome.