Retinoic acid alleviates rotavirus-induced intestinal damage by regulating redox homeostasis and autophagic flux in piglets.

Rotaviruses (RV) are a major cause of severe gastroenteritis, particularly in neonatal piglets. Despite the availability of effective vaccines, the development of antiviral therapies for RV remains an ongoing challenge. Retinoic acid (RA), a metabolite of vitamin A, has been shown to have anti-oxidative and antiviral properties. However, the mechanism by which RA exerts its intestinal-protective and antiviral effects on RV infection is not fully understood. The study investigates the effects of RA supplementation in Duroc × Landrace × Yorkshire (DLY) piglets challenged with RV. Thirty-six DLY piglets were assigned into six treatments, including a control group, RA treatment group with two concentration gradients (5 and 15 mg/d), RV treatment group, and RV treatment group with the addition of different concentration gradients of RA (5 and 15 mg/d). Our study revealed that RV infection led to extensive intestinal architecture damage, which was mitigated by RA treatment at lower concentrations by increasing the villus height and villus height/crypt depth ratio (P < 0.05), enhancing intestinal stem cell signaling and promoting intestinal barrier functions. In addition, 15 mg/d RA supplementation significantly increased NRF2 and HO-1 protein expression (P < 0.05) and GSH content (P < 0.05), indicating that RA supplementation can enhance anti-oxidative signaling and redox homeostasis after RV challenge. Additionally, the research demonstrated that RA exerts a dual impact on the regulation of autophagy, both stimulating the initiation of autophagy and hindering the flow of autophagic flux. Through the modulation of autophagic flux, RA influence the progression of RV infection. These findings provide new insights into the regulation of redox hemostasis and autophagy by RA and its potential therapeutic application in RV infection.

Yucca schidigera purpurea-sourced arabinogalactan polysaccharides augments antioxidant capacity facilitating intestinal antioxidant functions.

This study isolated and purified a novel homogeneous arabinogalactan polysaccharide from Yucca schidigera extract (YSE), unveiled its unique structure and explored its antioxidant function. Firstly, the antioxidant potential of YSE was demonstrated in piglet trials. A homogeneous polysaccharide with a molecular weight of 24.2 kDa, designated as Yucca schidigera polysaccharide B (YPB), was isolated and purified from YSE. The monosaccharide composition of YPB was Rha, Araf, Galp, and Glcp, whose molar percentages were 2.8 %, 11.6 %, 45.5 %, and 40.0 %, respectively. Methylation analysis combined with 1D and 2D nuclear magnetic resonance showed that YPB was a complex polysaccharide with a main glycosidic linkage pattern of →2)-α-ʟ-Rha-(1 â†’ 3)-ß-ᴅ-Galp-(1→3)-ß-ᴅ-Galp-(1 â†’ 3)-ß-ᴅ-Galp-(1 â†’ 3)-ß-ᴅ-Glcp-(1→, and branched Araf and Galp fragments were connected with the main chain through →3,6)-ß-ᴅ-Galp-(1→, →3,4)-ß-ᴅ-Glcp-(1→, and →2,4)-α-ʟ-Rha-(1→ linkages. Following the in vitro biochemical assays of bioactive components, YPB should be the contributor to the antioxidant activity in YSE. Based on the establishment of oxidative stress model, YPB exhibited strong antioxidant capacity and activated NRF2 pathway, and then provided protection against the damage induced oxidative stress in IPEC-J2 cells and rats. Further analysis with inhibitors found that this antioxidant effect was attributed to its interaction with epidermal growth factor receptor and mannose receptor, and stimulating PI3K/AKT pathway.

Effect of small peptide chelated iron on growth performance, immunity and intestinal health in weaned pigs.

BACKGROUND: Small peptide chelated iron (SPCI), a novel iron supplementation in pig diets, owns growth-enhancing characteristics. Although a number of researches have been performed, there is no clear-cut evidence to show the exact relationship between the dose and effects of small peptide chelated minerals. Therefore, we investigated the effect of dietary supplementation of SPCI at different doses in the growth performance, immunity, and intestinal health in weaned pigs. METHODS: Thirty weaned pigs were randomly assigned into five groups and feed with basal diet or the basal diet containing 50, 75, 100, or 125 mg/kg Fe as SPCI diets. The experiment lasted for 21 d and on day 22, blood samples were collected 1 h later. The tissue and intestinal mucosa samples were collected following. RESULTS: Our results showed that the feed to gain ratio (F:G) decreased with different levels of SPCI addition (P < 0.05). The average daily gain (ADG) (P < 0.05) and digestibility of crude protein (P < 0.01) decreased with 125 mg/kg SPCI addition. With dietary different levels of SPCI addition, the serum concentrations of ferritin (quadratic, P < 0.001), transferrin (quadratic, P < 0.001), iron content in liver (quadratic, P < 0.05), gallbladder (quadratic, P < 0.01) and fecal (quadratic, P < 0.01) increased quadraticly. While the iron content in tibia (P < 0.01) increased by 100 mg/kg SPCI supplementation. Dietary 75 mg/kg SPCI addition increased the serum insulin-like growth factor I (IGF-I) (P < 0.01) and SPCI (75 ~ 100 mg/kg) addition also increased the serum content of IgA (P < 0.01). The serum concentrations of IgG (quadratic, P < 0.05) and IgM (quadratic, P < 0.01) increased quadraticly by different levels of SPCI supplementation. Moreover, different levels of SPCI supplementation decreased the serum concentration of D-lactic acid (P < 0.01). The serum glutathione peroxidase (GSH-Px) (P < 0.01) elevated but the malondialdehyde (MDA) (P < 0.05) decreased by 100 mg/kg SPCI addition. Interestingly, SPCI supplementation at 75 ~ 100 mg/kg improved the intestinal morphology and barrier function, as suggested by enhanced villus height (P < 0.01) and villus height/crypt depth (V/C) (P < 0.01) in duodenum, as well as jejunum epithelium tight-junction protein ZO-1 (P < 0.01). Moreover, SPCI supplementation at 75 ~ 100 mg/kg increased the activity of duodenal lactase (P < 0.01), jejunal sucrase (P < 0.01) and ileal maltase (P < 0.01). Importantly, the expression levels of divalent metal transporter-1(DMT1) decreased with different levels of SPCI addition (P < 0.01). In addition, dietary SPCI supplementation at 75 mg/kg elevated the expression levels of critical functional genes such as peptide transporter-1(PePT1) (P = 0.06) and zinc transporter 1 (ZnT1) (P < 0.01) in ileum. The expression levels of sodium/glucose co-transporter-1 (SGLT1) in ileum (quadratic, P < 0.05) increased quadraticly by different levels of SPCI addition and amino acid transporter-1 (CAT1) in jejunum(P < 0.05) also increased by 100 mg/kg SPCI addition. CONCLUSIONS: Dietary SPCI supplementation at 75 ~ 100 mg/kg improved growth performance by elevated immunity and intestinal health.

Effect of 3-caffeoylquinic acid on growth performance, nutrient digestibility, and intestinal functions in weaned pigs.

Phenolic acid like with the 3-caffeoylquini acid (3-CQA) is formed by caffeic acid and qunic acid. This study was conducted to explore the effect of 3-CQA on growth performance and intestinal functions in weaned pigs. A total of 180 weaned pigs were randomly allocated into five treatments with 6 replicate pens per treatment (6 pigs per pen). Pigs in the control group (CON) were fed with basal diet (BD), and the others in the experimental groups were fed with BD and supplemented with 12.5, 25, 50, and 100 mg/kg 3-CQA. On day 43, the blood sample-collected pigs in the CON and optimal-dose group (only based on growth performance) were picked, and housed in metabolism cages (a total of 12 pigs, N = 6). 3-CQA increased the feed efficiency from days 21 to 42 of the trial and throughout the trial (P < 0.05). 3-CQA increased the serum concentrations of total protein, albumin, and total cholesterol (P < 0.05). Moreover, 3-CQA supplementation at 25 mg/kg increased the apparent digestibility of DM, energy, and ash (P < 0.05). Interestingly, 3-CQA decreased the crypt depth but increased the ratio of villus height to crypt depth in the jejunum and ileum (P < 0.05). Moreover, 3-CQA also increased the activities of sucrase, lactase, and catalase in the jejunal mucosa, and increased the activities of alkaline phosphatase and superoxide dismutase in the ileal mucosa (P < 0.05). 3-CQA also increased the abundance of secretory immunoglobulin A in the ileal mucosa (P < 0.05). Importantly, 3-CQA not only elevated the expression levels of critical functional genes such as the zonula occludens-1 , occludin, solute carrier family 7 , and nuclear factor erythroid 2-related factor 2 (Nrf2) in the duodenum but also elevated the expression levels of divalent metal transporter-1 and Nrf2 in the jejunum (P < 0.05). These results suggested a positive effect of 3-CQA supplementation on the growth and intestinal functions of weaned pigs. The mechanisms of action may be associated with elevated anti-oxidant capacity and improved intestinal barrier functions.

In last decades, swine producers used antibiotics as growth promoter added into diet. However, the pharmaceutical use of antibiotics is prohibited by the legislation of several countries due to potential health and environmental concerns. Therefore, the development of substitutes for traditionally used antibiotics has attracted considerable research interest worldwide. Natural phnolic acid like with the 3-CQA is an important component of biologically active phenols isolated from various natural plants. This study was carried out to evaluate the effect of 3-CQA on growth performance, nutrient digestibility, and intestinal functions in pigs. Results indicated that dietary 3-CQA supplementation improved the growth performance, nutrients digestibility in weaned pigs. The beneficial effects of 3-CQA supplementation on growth and intestinal functions suggested that it could serve as a natural potent substitute for antibiotics.

The effect of dietary Yucca schidigera extract supplementation on productive performance, egg quality, and gut health in laying hens with Clostridium perfringens and coccidia challenge.

Yucca schidigera extract (YSE) is a green feed additive that is known to reduce toxic gas emissions and promote intestinal health in animal production. This study investigated the potential of dietary YSE supplementation to mitigate the negative effect of Clostridium perfringens and coccidia infection on productive performance and gut health in laying hens. A total of 48 Lohmann gray laying hens (35 wk of age) were randomly allotted to 1 of 2 groups (n = 24) fed with either a basal diet or a YSE-supplemented diet for 45 d. From d 36 to 45, half of the hens in each group were orally administrated with Clostridium perfringens type A and coccidia. This challenge impaired productive performance and egg quality (P < 0.05), destroyed jejunal morphology and functions (P < 0.05), induced jejunal epithelial cell apoptosis (P < 0.05), and downregulated the antioxidant capacity and Nrf2 pathway expression of jejunal mucosa (P < 0.05) in laying hens. Supplementing YSE in the laying hen diet, to some extents, improved productive performance and egg quality (P < 0.05), and alleviated the effect of challenge on morphology, functions, cell apoptosis, and antioxidant capacity in the jejunum (P < 0.05). Overall, the results suggested that dietary YSE supplementation might mitigate the negative effects of Clostridium perfringens and coccidia infection on gut health, and thereby improve the productive performance and egg quality of laying hens, possibly through enhancing the antioxidant capacity of the jejunum.

Dietary ferulic acid supplementation improves antioxidant capacity and lipid metabolism in liver of piglets with intrauterine growth retardation.

Intrauterine growth retardation (IUGR) can result in early liver oxidative damage and abnormal lipid metabolism in neonatal piglets. Ferulic acid (FA), a phenolic compound widely found in plants, has many biological functions, such as anti-inflammation and anti-oxidation. Thus, we explored the effects of dietary FA supplementation on antioxidant capacity and lipid metabolism in newborn piglets with IUGR. In the study, 24 7-day-old piglets were divided into three groups: normal birth weight (NBW), IUGR, and IUGR + FA. The NBW and IUGR groups were fed formula milk as a basal diet, while the IUGR + FA group was fed a basal diet supplemented with 100 mg/kg FA. The trial lasted 21 days. The results showed that IUGR decreased absolute liver weight, increased transaminase activity, reduced antioxidant capacity, and disrupted lipid metabolism in piglets. Dietary FA supplementation enhanced absolute liver weight, reduced serum MDA level and ROS concentrations in serum and liver, markedly increased serum and liver GSH-PX and T-SOD activities, decreased serum HDL-C and LDL-C and liver NEFA, and increased TG content and HL activity in the liver. The mRNA expression related to the Nrf2-Keap1 signaling pathway and lipid metabolism in liver were affected by IUGR. Supplementing FA improved the antioxidant capacity of liver by down-regulating Keap1 and up-regulating the mRNA expression of SOD1 and CAT, and regulated lipid metabolism by increasing the mRNA expression level of Fasn, Pparα, LPL, and CD36. In conclusion, the study suggests that FA supplementation can improve antioxidant capacity and alleviate lipid metabolism disorders in IUGR piglets.

Eugenol Alleviates TGEV-Induced Intestinal Injury via Suppressing ROS/NLRP3/GSDMD-Dependent Pyroptosis.

Transmissible gastroenteritis virus (TGEV), a coronavirus, is one of the main causative agents of diarrhea in piglets and significantly impacts the global swine industry. Pyroptosis is involved in the pathogenesis of coronavirus, but its role in TGEV-induced intestinal injury has yet to be fully elucidated. Eugenol, an essential plant oil, plays a vital role in antiviral innate immune responses. We demonstrate the preventive effect of eugenol on TGEV infection. Eugenol alleviates TGEV-induced intestinal epithelial cell pyroptosis and reduces intestinal injury in TGEV-infected piglets. Mechanistically, eugenol reduces the activation of NLRP3 inflammasome, thereby inhibiting TGEV-induced intestinal epithelial cell pyroptosis. In addition, eugenol scavenges TGEV-induced reactive oxygen species (ROS) increase, which in turn prevents TGEV-induced NLRP3 inflammasome activation and pyroptosis. Overall, eugenol protects the intestine by reducing TGEV-induced pyroptosis through inhibition of NLRP3 inflammasome activation, which may be mediated through intracellular ROS levels. These findings propose that eugenol may be an effective strategy to prevent TGEV infection.

Dietary lactate supplementation can alleviate DSS-induced colitis in piglets.

Colitis is a common and complex intestinal inflammatory disease in which lactate, a metabolite of anaerobic glycolysis, plays a crucial role. Our study aimed to investigate the alleviated effect of lactate in colitis, and to provide a nutritional measure to alleviate colitis injury. The variations in colonic lactate in piglets with DSS-induced colitis were investigated in Experiment 1 (Exp.1). Thirty weaned pigs were allotted into three groups and sampled at different stages of DSS-induced colitis (days 0, 5, and 7). The colonic level of lactate and interleukin 10 (IL-10) was significantly decreased on day 5 when compared to day 0. Colonic lactate, IL-10, and G protein receptor 81 (GPR81) levels were significantly increased on day 7 when compared to day 5. Sixty weaned piglets were assigned to control (basal diet), DSS (basal diet with DSS gavage), or lactate (2% lactate supplementation diet with DSS gavage) groups to investigate the effects of lactate on DSS-induced colitis in Experiment 2 (Exp.2). Lactate reduced the disease activity index (DAI), DSS-induced impairment of colonic structure in response to the critical inflammatory cytokines interleukin 1ß (IL-1ß) and interleukin 18 (IL-18) when compared with the DSS group. Furthermore, GPR-81 levels, colonic M2 macrophages, and IL-10 levels, the colonic antioxidant capacity, colonic butyrate levels were increased, and eventually improved growth performance post-colitis. The results of this study show that lactate was decreased at the peak of colitis, accumulated in subsidized colitis. Furthermore, dietary lactate supplementation helped to alleviate DSS-induced colitis injury.

Daidzein supplementation improved fecundity in sows via modulation of ovarian oxidative stress and inflammation.

Adequate ovarian hormones secretion is essential for pregnancy success. Oxidative damage and following inflammation can destroy the ovarian normal function in mammals. Daidzein (DAI) is a classical isoflavonic phytoestrogen with specific oestrogenic activity. This study aimed to explore the effects of daidzein supplementation on fertility and ovarian characteristics of sows through biochemical analysis and RNA-seq technology. Twelve multiparous Yorkshire × Landrace sows were randomly divided into CON and DAI groups. We found that DAI increased total number of embryos as well as P4 and E2 levels of serum. DAI not only elevated the activities of T-AOC and GSH-Px, but also tended to decrease the content of MDA and IL-6 in the serum. In ovary, RNA-Seq identified 237 differentially expressed genes (DEGs), and GO analysis showed that these DEGs were linked to functions associated with immune dysfunction. Moreover, STRING analysis demonstrated that most interacting nodes were TLR-4, LCP2, and CD86. Furthermore, DAI decreased the content of MDA, IL-1ß, IL-6, and TNF-α, and increased the activities of T-AOC and CAT in ovarian tissue. Interestingly, a partial mantel correlation showed that T-AOC was the strongest correlation between the ovarian dataset and selected DEGs. Additionally, DAI supplementation not only increased the protein expressions of Nrf2, HO-1, and NQO1, but also decreased the protein expressions of TLR-4, p-NFκB, p-AKT, and p-IκBα. Altogether, our results indicated that DAI could ameliorate ovarian oxidative stress and inflammation in sows, which might be mediated by suppressing the TLR4/NF-κB signaling pathway and activating the Nrf2/HO-1 signaling pathway.

1,25-Dihydroxyvitamin D3 Negatively Regulates the Inflammatory Response to Porcine Epidemic Diarrhea Virus Infection by Inhibiting NF-κB and JAK/STAT Signaling Pathway in IPEC-J2 Porcine Epithelial Cells.

Porcine epidemic diarrhea virus (PEDV) infection causes watery diarrhea and vomiting in piglets. The pathogenesis of PEDV infection is related to intestinal inflammation. It is known that 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has potent anti-inflammatory activity, but it is unknown whether 1,25(OH)2D3 can inhibit the PEDV-induced inflammatory response and the underlying mechanism. We used transcriptome analysis, gene and protein expression, RNA interference and overexpression, and other techniques to study the anti-inflammatory effects of 1,25(OH)2D3 on PEDV infection in IPEC-J2 cells. The results showed that interleukin 19 (IL-19) and C-C motif chemokine ligand 20 (CCL20) gene expression were enhanced with the increase in PEDV infection time in IPEC-J2 cells. Interestingly, 1,25(OH)2D3 supplementation obviously inhibited IL-19 and CCL20 expression induced by PEDV. Meanwhile, we also found that 1,25(OH)2D3 reduced p-NF-κB, p-STAT1, and p-STAT3 protein levels induced by PEDV at 24 h post-infection. IκBα and SOCS3, NF-κB, and STAT inhibitor respectively, were increased by 1,25(OH)2D3 supplementation upon PEDV infection. In addition, 1,25(OH)2D3 supplementation inhibited ISG15 and MxA expression induced by PEDV. Although 1,25(OH)2D3 suppressed the JAK/STAT signal pathway and antiviral gene expression, it had no significant effects on PEDV replication and IFN-α-induced antiviral effects. In addition, when the vitamin D receptor (VDR) was silenced by siRNA, the anti-inflammatory effect of 1,25(OH)2D3 was inhibited. Meanwhile, the overexpression of VDR significantly downregulated IL-19 and CCL20 expression induced by PEDV infection. Together, our results provide powerful evidence that 1,25(OH)2D3 could alleviate PEDV-induced inflammation by regulating the NF-κB and JAK/STAT signaling pathways through VDR. These results suggest that vitamin D could contribute to inhibiting intestinal inflammation and alleviating intestinal damage in PEDV-infected piglets, which offers new approaches for the development of nutritional strategies to prevent PEDV infection in piglets.

Agrobacterium sp. ZX09 ß-Glucan Attenuates Enterotoxigenic Escherichia coli-Induced Disruption of Intestinal Epithelium in Weaned Pigs.

To explore the protective effect of dietary ß-glucan (BGL) supplementation on intestinal epithelium exposure to enterotoxigenic Escherichia coli (ETEC), thirty-two weaned pigs were assigned to four groups. Pigs were fed with a basal diet or basal diet containing 500 mg/kg BGL, and were orally infused with ETEC or culture medium. Results showed BGL supplementation had no influence on growth performance in weaned pigs. However, BGL supplementation increased the absorption of D-xylose, and significantly decreased the serum concentrations of D-lactate and diamine oxidase (DAO) in the ETEC-challenged pigs (p < 0.05). Interestingly, BGL significantly increased the abundance of the zonula occludens-1-(ZO-1) in the jejunal epithelium upon ETEC challenge (p < 0.05). BGL supplementation also increased the number of S-phase cells and the number of sIgA-positive cells, but significantly decreased the number of total apoptotic cells in the jejunal epithelium upon ETEC challenge (p < 0.05). Moreover, BGL significantly increased the duodenal catalase (CAT) activity and the ileal total superoxide dismutase (T-SOD) activity in the ETEC-challenged pigs (p < 0.05). Importantly, BGL significantly decreased the expression levels of critical inflammation related proteins such as the tumor necrosis factor-α (TNF-α), interlukin-6 (IL-6), myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) in the jejunal and ileal mucosa upon ETEC challenge (p < 0.05). BGL also elevated the propanoic acid content and the abundance of Lactobacillus and Bacillus in the colon upon ETEC challenge (p < 0.05). These results suggested BGL could alleviate the ETEC-induced intestinal epithelium injury, which may be associated with suppressed inflammation and improved intestinal immunity and antioxidant capacity, as well as the improved intestinal macrobiotic.

Effects of ferulic acid on the growth performance, antioxidant capacity, and intestinal development of piglets with intrauterine growth retardation.

Neonates with intrauterine growth retardation (IUGR) are prone to suffer from delayed postnatal growth and development during the early stages of life. Ferulic acid (FA) is a phenolic compound that is abundantly present in fruits and vegetables and has various health benefits. Hence, we explored whether FA supplementation could favorably affect the growth performance, antioxidant capacity, and intestinal development of piglets with IUGR. In total, eight normal-birth-weight (NBW) piglets and 16 piglets with IUGR (age, 7 d) were assigned to be fed either basic formula milk (NBW and IUGR groups, respectively) or basic formula milk supplemented with 100 mg/kg FA (IUGR + FA group) for 21 d. At necropsy, the serum and intestinal tissues were collected. FA supplementation increased (P < 0.05) the feed conversion ratio and serum total superoxide dismutase and catalase activities in piglets with IUGR. Moreover, FA supplementation elevated (P < 0.05) the duodenal lactase and maltase activities, jejunal villus height and jejunal maltase activity but reduced (P < 0.05) the duodenal crypt depth and duodenal and jejunal cell apoptosis, cleaved cysteinyl aspartic acid protease-3 (caspase-3) content and cleaved caspase-9 content in piglets with IUGR. In summary, FA supplementation could elevate antioxidant capacity and facilitate intestinal development, thus resulting in increased feed efficiency in piglets with IUGR.

Intrauterine growth retardation (IUGR) impairs postnatal growth and development in neonatal piglets. Ferulic acid (FA) is a ubiquitous phenolic compound that is present in numerous fruits and vegetables and possesses various biological activities. However, little is known about whether FA supplementation has beneficial effects on the growth performance, antioxidant capacity, and intestinal development of piglets with IUGR. Our findings provide important implications for treating piglets with IUGR after birth by stimulating intestinal development with FA supplementation.

Yucca schidigera extract decreases nitrogen emission via improving nutrient utilisation and gut barrier function in weaned piglets.

Yucca schidigera extract (YE) can decrease ammonia concentration in livestock housing, which could be associated with the inhibition of urease. The aim of this study was to investigate the other possible reasons of dietary YE supplementation reducing nitrogen emission in weaned piglets. A total of 14 crossbred weaned barrows were allotted into two groups fed the diets supplementing 0 and 120 mg/kg YE for 14 days. The YE administration decreased F/G ratio and hindgut NH3 -N production in weaned piglets (p < 0.05). Dietary YE supplementation decreased serum urea nitrogen levels, and increased nutrient digestibility, which could be related to the improvement of morphology, digestive and absorptive enzyme activities, and nutrient transporter mRNA expression in jejunal mucosa of weaned piglets (p < 0.05). The mRNA expression of tight junction proteins, mucins and apoptosis-related genes was also improved by YE treatment in jejunal mucosa of weaned piglets (p < 0.05). In addition, dietary YE supplementation regulated the microbiota structure and volatile fatty acid content in distal intestine of weaned piglets (p < 0.05). These results suggest that YE administration can decrease hindgut NH3 -N production in weaned piglets, which is associated with the increased nutrient utilization and gut-barrier function.

Dietary supplementation of fructo-oligosaccharides alleviates enterotoxigenic E. coli-induced disruption of intestinal epithelium in a weaned piglet model.

Diarrhoea caused by pathogens such as enterotoxigenic E. coli (ETEC) is a serious threat to the health of young animals and human infants. Here, we investigated the protective effect of fructo-oligosaccharides (FOS) on the intestinal epithelium with ETEC challenge in a weaned piglet model. Twenty-four weaned piglets were randomly divided into three groups: (1) non-ETEC-challenged control (CON); (2) ETEC-challenged control (ECON); and (3) ETEC challenge + 2·5 g/kg FOS (EFOS). On day 19, the CON pigs were orally infused with sterile culture, while the ECON and EFOS pigs were orally infused with active ETEC (2·5 × 109 colony-forming units). On day 21, pigs were slaughtered to collect venous blood and small intestine. Result showed that the pre-treatment of FOS improved the antioxidant capacity and the integrity of intestinal barrier in the ETEC-challenged pigs without affecting their growth performance. Specifically, compared with ECON pigs, the level of GSH peroxidase and catalase in the plasma and intestinal mucosa of EFOS pigs was increased (P < 0·05), and the intestinal barrier marked by zonula occluden-1 and plasmatic diamine oxidase was also improved in EFOS pigs. A lower level (P < 0·05) of inflammatory cytokines in the intestinal mucosa of EFOS pigs might be involved in the inhibition of TLR4/MYD88/NF-κB pathway. The apoptosis of jejunal cells in EFOS pigs was also lower than that in ECON pigs (P < 0·05). Our findings provide convincing evidence of possible prebiotic and protective effect of FOS on the maintenance of intestinal epithelial function under the attack of pathogens.

Dietary Arginine Supplementation Improves Intestinal Mitochondrial Functions in Low-Birth-Weight Piglets but Not in Normal-Birth-Weight Piglets.

Our previous studies revealed that L-arginine supplementation had beneficial effects on intestinal barrier functions of low-birth-weight (LBW) piglets, which were associated with the enhanced antioxidant capacity. Moreover, mitochondrial functions are closely related to the redox state. This study was to explore potential mechanisms of L-arginine-induced beneficial effects against intestinal dysfunction by regulating mitochondrial function of LBW piglets. Twenty 4-day-old normal birth weight (NBW) piglets (BW: 2.08 ± 0.09 kg) and 20 LBW siblings (BW: 1.16 ± 0.07 kg) were artificially fed either a basal diet or a basal diet supplemented with 1.0% L-arginine for 21 d, respectively. Growth performance, intestinal morphology, redox status, mitochondrial morphology, and mitochondrial functions were examined. Data were subjected to two-way analysis of variance. LBW piglets presented lower (p < 0.05) ADG, shorter (p < 0.05) intestinal villus height, lower (p < 0.05) jejunal adenosine triphosphate (ATP) content and higher (p < 0.05) concentrations of Ca2+ and 8-OH-dG in jejunal mitochondria, compared with NBW piglets. Supplementation with 1.0% L-arginine significantly increased (p < 0.05) ADG, the activities of CAT, SOD, and GPx, intestinal villus height and mRNA abundances of ZO-1 (2-fold) in the jejunum of LBW piglets, but not in NBW piglets. Furthermore, the concentrations of ATP and the transcription of COX IV, COX V genes were up-regulated (p < 0.05) and the concentration of Ca2+ and 8-OH-dG were decreased (p < 0.05) in arginine-treated LBW piglets. The results suggest that mitochondrial morphology is affected, and mitochondrial functions are impaired in the jejunum of LBW piglets. While supplementation with 1.0% L-arginine relieved intestinal dysfunction through enhancing antioxidant capacity and improving mitochondrial functions via repairing mitochondrial morphology, normalizing mitochondrial calcium, and increasing ATP concentration in the jejunum of LBW piglets. However, supplementation with L-arginine has no significant beneficial effects on intestinal health in NBW piglets.

Chitosan oligosaccharide attenuates endoplasmic reticulum stress-associated intestinal apoptosis via the Akt/mTOR pathway.

Endoplasmic reticulum stress (ERS) and apoptosis are widely considered as essential factors associated with intestinal disorders, whereas nutritional therapeutic approaches targeting ERS may control disease activity. Thus, we focus on the potential benefit of chitosan oligosaccharide (COS) on repressing ERS and ERS-induced apoptosis. In this study, we used the ERS model with tunicamycin (TM)-induced IPEC-J2 cells in vitro and nutrient deprivation-induced ERS in piglets to evaluate the protective mechanism of COS against ERS and ERS-induced apoptosis. The results showed that cells were characterized by activation of the unfolded protein response (UPR) and increased epithelial apoptosis upon exposure to TM. However, these changes were significantly attenuated by COS and the expressions of Akt and mTORC1 were inhibited. Furthermore, a specific inhibitor of mTOR confirmed the suppression of Akt and reduced the activation of the UPR and apoptosis. In vivo, COS protected against nutrient deprivation-induced ERS in the jejunum of piglets, in which the overexpression of the UPR and apoptosis was rescued. Consistently, COS attenuated nutrient deprivation-induced disruption of intestinal barrier integrity and functional capacity. Together, we provided the first evidence that COS could protect against intestinal apoptosis through alleviating severe ERS, which may be related to the inhibition of the Akt/mTOR signaling pathway.

Effects of essential oil on growth performance, digestibility, immunity, and intestinal health in broilers.

Essential oils (EO) are concentrated hydrophobic liquids containing volatile aromatic compounds obtained from plants, which have properties as withdrawn antibiotic growth promoters. The objective of this study was to explore the effects of EO on growth performance, digestibility, immunity and intestinal health in broilers. A total of 500 1-day-old Arbor Acre broilers were randomly put into five groups with 10 replicate cages containing 10 birds each. Birds in the 5 groups were fed a basal diet (CON), and basal diet with 50, 100, 200 or 400 mg/kg EO (EO0.5, EO1, EO2 and EO4) for 42 d respectively. Birds were euthanized at 21d and 42 d, blood and tissue samples were collected. In the study, the digestibility of DM, GE and EE in groups with EO supplementation were significantly increased compared with CON group (P < 0.05). However, only EO2 and EO4 significantly increased the digestibility of CP compared with CON group (P < 0.05). In contrast to CON group, EO0.5 and EO1 in jejunum at 21 d, and EO1 in jejunum at 42 d markedly increased the activity of sucrase (P < 0.05). In addition, the level of SOD of EO2 and EO4 in serum at 21 d was significantly increased compared with CON group (P < 0.05). What's more, the concentration of intestinal mucosa SIgA in jejunum and ileum at 21 d of groups with EO supplementation was significantly increased compared with CON group (P < 0.05). Moreover, V/C in jejunum at 21 d of groups with EO supplementation, CD in jejunum at 42 d was also significantly increased to compare with CON group (P < 0.05). Furthermore, the expression levels of critical genes associated with nutrient transportation (i.e., GLUT2, SGLT1, SLC38A, SLC79A and SLC27A4) and barrier function (TJP1) were quadratically and linearly up-regulated in jejunum and ileum with EO supplementation (P < 0.05). These results suggest that EO has a positive impact on growth, immunity and intestinal health in broilers, and 200 mg/kg of EO was recommended in broiler diet.

1,25-Dihydroxyvitamin D3 inhibits porcine epidemic diarrhea virus replication by regulating cell cycle resumption in IPEC-J2 porcine epithelial cells.

Porcine epidemic diarrhea virus (PEDV) infection causes heavy economic losses in the pig industry. Currently, the lack of effective treatments prompts new antiviral researches. We have shown that 25-hydroxyvitamin D3 supplementation alleviated PEDV infection in weaned pigs before. However, it is not clear whether vitamin D inhibits PEDV replication. In this study, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) inhibited PEDV induced mitochondria damage and cell apoptosis. In addition, 1,25(OH)2D3 treatment decreased PEDV nucleocapsid gene and protein levels in IPEC-J2 cells. Transcriptomic data showed that PEDV infection altered the expression of 5316 genes (2498 up, 2818 down) in IPEC-J2 cells. The differentially expressed genes were mainly involved in cell cycle process, ribonucleoprotein complex biogenesis, mitotic nuclear division, and other biological processes. Then we examined the effects of PEDV infection on cell cycle progression in IPEC-J2 cells, and the results showed that PEDV induced G0/G1 phase arrest. G0/G1-phase arrest was also conducive to PEDV replication. However, 1,25(OH)2D3 treatment decreased G0/G1 phase percentage induced by PEDV. Cyclin D and cyclin E mRNA expression were also increased by 1,25(OH)2D3 supplementation upon PEDV infection. Moreover, the regulation of 1,25(OH)2D3 on cell cycle progression was abrogated by ERK1/2 inhibitor, as well as the mRNA expression of cyclin D. The inhibition of 1,25(OH)2D3 on PEDV replication was also eliminated by ERK1/2 inhibitor. Taken together, these results demonstrated that 1,25(OH)2D3 supplementation inhibited PEDV replication, and the anti-virus effect of 1,25(OH)2D3 was mediated in part by regulating cell cycle progression through ERK1/2 signaling pathway.

Fermented Diet Liquid Feeding Improves Growth Performance and Intestinal Function of Pigs.

Accumulating evidences demonstrate that fermented feed and liquid feeding exerted a great beneficial influence on growth performance and health in the pig industry. This experiment was conducted to evaluate the effects of fermented liquid feeding on the growth performance and intestinal function of pigs. Two hundred and eighty-eight 27-day-old weaned piglets (8.21 ± 0.27 kg) were randomly allocated to a control group (basal diet (CON)), an antibiotic group (basal diet supplemented with antibiotics (AB)) and a fermented liquid feeding group (basal diet with fermented liquid feeding (FLF)), with 6 replicates per treatment and 16 weaned piglets per replicate. The experiment lasted for 160 days. Fresh fecal samples were collected to evaluate the apparent total tract digestibility (ATTD) of nutrients from the last 4 days of each stage. The results are shown as follows: (1) Compared with the CON group, in the whole stage, the FLF diet significantly increased the final body weight (BW) and ADG of pigs (P < 0.05), and had a tendency to increase ADFI (P = 0.086), but had no effect on F/G. (2) The ATTD of dry matter (DM), crude protein (CP), ether extract (EE), crude ash (CA), crude fiber (CF), gross energy (GE), calcium (Ca) and total phosphorus (TP) in the FLF group was significantly elevated compared with those of the CON group at 8-20 kg stage (P < 0.05). Meanwhile, the ATTD of EE in the FLF group was significantly increased compared with that of the CON group at the 50-75 kg and 100-125 kg stages (P < 0.05), and the ATTD of Ca was higher than that of CON group at the 100-125 kg stage (P < 0.05). (3) Compared with that of the CON group, the level of serum leptin in the FLF group had a tendency to decrease (P = 0.054), the level of serum ghrelin in the FLF group was significantly elevated (P < 0.05) and the level of serum peptide YY in the FLF group was significantly decreased (P < 0.05). (4) The abundance of Lactobacillus in cecal and colonic digesta was observably enhanced in FLF group. Meanwhile, the abundance of Escherichia coli in cecal and colonic digesta were dramatically reduced in the FLF group compared with that in the CON and AB groups (P < 0.05). (5) The levels of acetic acid in colonic digesta were significantly increased in the FLF group (P < 0.05), and an increasing trend was observed in total VFA in colonic digesta compared with CON (P < 0.1). The levels of acetic acid in colonic digesta were significantly promoted in the FLF group compared with that of the AB group (P < 0.05). In conclusion, these results indicate that fermented liquid feeding improved the growth performance of pigs, which might be associated with gastrointestinal hormone and intestinal functions.

Influences of Selenium-Enriched Yeast on Growth Performance, Immune Function, and Antioxidant Capacity in Weaned Pigs Exposure to Oxidative Stress.

This study elucidated the function role of dietary selenium-enriched yeast (SeY) supplementation on growth performance, immune function, and antioxidant capacity in weaned pigs exposure to oxidative stress. Thirty-two similarity weight pigs were randomly divided into four treatments: (1) nonchallenged control, (2) control+SeY, (3) control+diquat, and (4) control+SeY+diquat. The period of experiment was 21 days; on day 16, pigs were injected with diquat or sterile saline. Results revealed that oxidative stress was notably detrimental to the growth performance of piglets, but SeY supplementation ameliorated this phenomenon, which might be regarding the increasing of body antioxidant capacity and immune functions. In details, SeY supplementation improved the digestibility of crude protein (CP), ash, and gross energy (GE). Moreover, the serum concentrations of proinflammatory cytokines (TNF-α, IL-1ß, and IL-6), glutamic-pyruvic transaminase(GPT), and glutamic-oxaloacetic transaminase (GOT) were reduced via SeY supplemented, and serum concentrations of immunoglobulins A (IgA), IgG, and activities of antioxidant enzymes such as the superoxide dismutase (SOD), catalase (CAT) ,and glutathione peroxidase (GSH-Px) were improved in the diquat-challenged pigs (P < 0.05). In addition, SeY supplementation acutely enhanced the activities of these antioxidant enzymes in the liver and thymus upon diquat challenge, which involved with the upregulation of the critical genes related antioxidant signaling such as the nuclear factor erythroid-derived 2-related factor 2 (Nrf-2) and heme oxygenase-1 (HO-1) (P < 0.05). Importantly, we also found that SeY supplementation apparently reduced the malondialdehyde (MDA) concentrations in the liver, thymus, and serum (P < 0.05). Specifically, the expression levels of TNF-α, IL-6, IL-1ß, Toll-like receptor 4 (TLR-4), and nuclear factor-κB (NF-κB) in the liver and thymus were downregulated by SeY upon diquat challenge. These results suggested that SeY can attenuate oxidative stress-induced growth retardation, which was associated with elevating body antioxidant capacity, immune functions, and suppressed inflammatory response.