Fish oil enhances intestinal integrity and inhibits TLR4 and NOD2 signaling pathways in weaned pigs after LPS challenge

Weaning Stress Aggravates Defense Response and the Burden of Protein Metabolism in Low-Birth-Weight Piglets

The effect of low birth weight (LBW) on piglet development has been widely demonstrated. However, the reasons for the significant decline in the growth performance of LBW piglets after weaning remain poorly understood. This study aimed to investigate the underlying mechanisms of this phenomenon. At 21 days of age, 24 normal-birth-weight (NBW) piglets and 24 LBW piglets were selected and divided into four groups-NBW control, NBW weaning, LBW control, and LBW weaning-with 12 replicates per group (1 piglet per replicate). Control groups were euthanized on the same day, while weaning groups were weaned and sampled 3 days later. The results showed that the body weight of NBW piglets increased, whereas that of LBW piglets decreased, after 3 days of weaning. Compared with NBW piglets, LBW piglets exhibited higher serum cortisol concentrations and lower villus height (p < 0.05). Weaning stress significantly increased serum cortisol and C-reactive protein concentrations in NBW piglets (p < 0.05), while no significant changes were observed in LBW piglets. However, weaning stress significantly increased serum blood urea nitrogen (BUN) concentrations (p < 0.05) in LBW piglets but not in NBW piglets. Additionally, weaning stress reduced the mRNA expressions of Occludin, Claudin-1, and Claudin-2 in the jejunum of NBW piglets (p < 0.05), as well as Occludin in the jejunum of LBW piglets (p < 0.05). Furthermore, weaning stress reduced the mRNA expressions of IL-6, TLR9, MyD88, TRIF and p65 NF-κB in the jejunum of NBW piglets (p < 0.05). In LBW piglets, weaning stress decreased the mRNA expressions of IL-2, TNF-α, NLRP3, TLR9, and NOD2 (p < 0.05). In conclusion, compared to NBW piglets, LBW piglets are more susceptible to weaning stress-induced protein metabolic disorders and intestinal barrier dysfunction, ultimately leading to impaired immune function and reduced growth performance. The results underscore the importance of tailored management strategies for piglets based on birth weight to mitigate weaning stress impacts.

Design, synthesis and activity evaluation of dual-target inhibitors against papain-like and main proteases of porcine epidemic diarrhea virus

INTRODUCTION

Porcine epidemic diarrhea (PED), caused by porcine epidemic diarrhea virus (PEDV), threatens the global pig industry due to lack of drugs. PEDV replication relies on PLpro and Mpro, which are crucial targets for inhibitors. Additionally, PLpro plays a role in modulating the host's immune response, and the inhibition of PLpro exhibits significant anti-inflammatory properties.

OBJECTIVES

A series of dual-targeted inhibitors of Mpro and PLpro were designed and synthesized, and their antiviral and anti-inflammatory activities were subsequently evaluated in vitro and in vivo.

METHODS

Dual-targeted inhibitors of Mpro and PLpro were designed by merging two series of Mpro inhibitors and PLpro inhibitors. sixty-four compounds were synthesized and screened in vitro by FRET for inhibitory activities and by RT-qPCR for antiviral activity on Vero-E6 cells. The anti-PEDV activity of f2 on Vero-E6 cells and IPEC-J2 cells was further confirmed by immunofluorescence. The mechanism by which f2 inhibited PEDV-induced inflammation was investigated by Western blot and RT-qPCR. The anti-colitis activity of f2 was verified in vivo.

RESULTS

Among the sixty-four synthesized compounds, seventeen potent dual-targeted inhibitors of PLpro and Mpro were identified with IC50 values less than 10 μM. Six compounds demonstrated excellent antiviral activity and safety in cell-based assays. The most potent compound f2 inhibited PEDV replication in Vero-E6 and IPEC-J2 cells with EC50 values of 1.17 ± 0.73 μM and 2.02 ± 0.56 μM, respectively, without cytotoxicity (CC50 > 800 μM). Moreover, f2 was found to inhibit the inflammatory response induced by PEDV infection via suppressing TLR2/PI3K/Akt/NF-κB signaling pathway. Oral f2 attenuated colitis by decreasing p65 phosphorylation, a major PEDV mortality cause. The in vivo acute toxicity test showed that oral administration of f2 did not affect the body weight and internal organs of mice.

CONCLUSIONS

In summary, a potent dual-targeted inhibitor of PLpro and Mpro, f2, was designed, synthesized, and found to be effective in the inhibition of PEDV replication and inflammatory response in vitro and in vivo.

Effects of Magnolia officinalis extract on the growth performance and immune function of weaned piglets

BACKGROUND

Magnolia officinalis is a medicinal herb known for its pharmacological properties and as a potential natural feed additive. We aimed to assess the effects of dietary Magnolia officinalis extract (MOE) on the growth performance and immune function of piglets, and explored the potential of MOE as a natural alternative to antibiotics for piglet nutrition during weaning.

RESULTS

Compared with the basal diet group (CK), the MOE diet significantly increased average daily feed intake and reduced diarrhea incidence and serum interleukin-6 (IL-6) levels. Compared with 0.1% MOE group, the 0.05% MOE group had lower diarrhea rates, eosinophils (EOS) count, EOS' percentage, and serum interleukin-4 levels. Compared with CK, 0.05% MOE supplementation in the diet could reduce the diarrhea incidence and the thymus index by elevating the levels of transforming growth factor-β (TGF-β) and interleukin-10 (IL-10) in the serum, jejunum, and ileum. Compared with the basal diet group, 0.05% MOE supplementation upregulated the mRNA expressions of IL-10 and TGF-β1 in the jejunum and ileum (P < 0.05) and those of IL-10, interleukin-1β (IL-1β), and interferon-γ (IFN-γ) in the thymus (P < 0.05). Moreover, 0.05% MOE increased the levels of butyric, isobutyric, isovaleric, and valeric acids in the colon.

CONCLUSIONS

MOE supplementation could modulate the immune status of animals, lower production costs, and contribute to more sustainable and ethical pig farming practices by promoting healthier growth and reducing disease susceptibility. Our findings offer a sustainable solution to antibiotic use in animal farming, addressing concerns about antibiotic resistance and food safety.

Antibiotics and Opportunities of Their Alternatives in Pig Production: Mechanisms Through Modulating Intestinal Microbiota on Intestinal Health and Growth

Antibiotics at subtherapeutic levels have been used in pig diets as antimicrobial growth promoters. However, concerns about antibiotic resistance have increased the demand for alternatives to these antimicrobial growth promoters. This review paper explores the mechanisms through which antimicrobial growth promoters and their alternatives exert their antimicrobial effects. Additionally, this systemic review also covers how modulation of intestinal microbiota by antimicrobial growth promoters or their alternatives affects intestinal health and, subsequently, growth of pigs. The mechanisms and effects of antimicrobial growth promoters and their alternatives on intestinal microbiota, intestinal health, and growth are diverse and inconsistent. Therefore, pig producers should carefully assess which alternative is the most effective for optimizing both profitability and the health status of pigs in their production system.

The effect of a water-soluble β-glucan on intestinal immunity and microbiota in LPS-challenged piglets

The intestine is the largest immune and barrier organ in the body, and diarrhea and even death during piglet development are related to dysfunction caused by intestinal barrier damage and inflammation. A water-soluble β-glucan produced by Agrobacterium ZX09 has been shown to have a beneficial effect on gastrointestinal health. The main objective of this study was to investigate whether pre-feeding β-glucan has a protective effect on LPS-induced immune stress in piglets. In this study, 24 weaned piglets (21-day-old; 6.64 ± 0.16 kg) were assigned to 4 treatments in a two × two factorial design with diet (with or without β-glucan) and immunological challenge (saline or LPS). Piglets were challenged with saline or LPS after 39 days of feeding 0 or 200 mg/kg β-glucan. The results demonstrated that β-glucan supplementation increased the average daily weight gain and daily feed intake, and decreased diarrhea rate of piglets. Intestinal inflammation symptoms and histological changes in LPS-challenged piglets were alleviated by pre-feeding of β-glucan. β-glucan supplementation reduced serum IL-1β (interleukin-1β) and NO (nitric oxide) secretion in piglets after LPS challenge (0.01 < p < 0.05). Supplementation with β-glucan downregulated the mRNA expression of IL-6 in piglets after LPS challenge (0.01 < p < 0.05). β-glucan supplementation enriched the short-chain fatty acid-producing bacteria, such as Agathobacter and Subdoligranulum (0.01 < p < 0.05), and increased the concentrations of propionate and butyrate (0.01 < p < 0.05). In conclusion, pre-feeding β-glucan can enhance piglet immunity and promote piglet growth by influencing gut microbiota composition and metabolism, and alleviate intestinal damage after LPS challenge.

Eicosapentaenoic acid enhances intestinal stem cell-mediated colonic epithelial regeneration by activating the LSD1-WNT signaling pathway

INTRODUCTION

Inflammatory bowel disease (IBD) is often associated with impaired proliferation and differentiation of intestinal stem cells (ISCs). Eicosapentaenoic acid (EPA), which is predominantly found in fish oil, has been recognized for its intestinal health benefits, although the potential mechanisms are not well understood.

OBJECTIVES

This study aimed to investigate the regulatory role and mechanism of EPA in colonic epithelial regeneration, specifically from the perspective of ISCs.

METHODS

Wild-type mice whose diet was supplemented with 5% EPA-enriched fish oil were subjected to dextran sulfate sodium (DSS) to induce colitis. We utilized intestinal organoids, ISC-specific lysine-specific demethylase 1 (LSD1) knockout mice, and WNT inhibitor-treated mice to explore how EPA influences ISC proliferation and differentiation. ISC proliferation, differentiation and apoptosis were assessed using tdTomato and propidium iodide tracer testing, histological analyses, and immunofluorescence staining.

RESULTS

EPA treatment significantly mitigated the symptoms of DSS-induced acute colitis, as evidenced by lower body weight loss and decreased disease activity index, histological scores and proinflammatory cytokine levels. Additionally, EPA increased the numbers of proliferative cells, absorptive cells, goblet cells, and enteroendocrine cells, which enhanced the regeneration of intestinal epithelium. Pretreatment with EPA increased ISC proliferation and differentiation, and protected against TNF-α-induced cell death in intestinal organoids. Mechanistically, EPA upregulated G protein-coupled receptor 120 (GPR120) to induce LSD1 expression, which facilitated ISC proliferation and differentiation in organoids. ISC-specific ablation of LSD1 negated the protective effect of EPA on DSS-induced colitis in mice. Moreover, EPA administration activated the WNT signaling pathway downstream of LSD1 in ISCs, while inhibiting WNT signaling abolished the beneficial effects of EPA.

CONCLUSIONS

These findings demonstrate that EPA promotes ISC proliferation and differentiation, thereby enhancing colonic epithelial regeneration through the activation of LSD1-WNT signaling. Consequently, dietary supplementation with EPA represents a promising alternative therapeutic strategy for managing IBD.

Necroptosis contributes to deoxynivalenol-induced activation of the hypothalamic-pituitary-adrenal axis in a piglet model

The mycotoxin deoxynivalenol (DON) is highly prevalent in cereals as an immune stressor. The hypothalamic-pituitary-adrenal (HPA) axis is activated during periods of stress, and the organism is accompanied by inflammation. Necroptosis is a newly identified type of cell death. However, the relationship between necroptosis and HPA axis activation induced by DON is rarely reported. Our study aimed to explore the role played by necroptosis in HPA activation in a stress of piglet model produced by DON. Our results indicated that both feeding with a contaminated-DON diet (4 ppm) and DON injection at 0.8 mg/kg BW increased the concentration of plasma corticotropin-releasing hormone (CRH) and adrenocorticotrophic hormone (ACTH) and the mRNA expression of adrenal steroidogenic acute regulatory protein (StAR). Furthermore, the mRNA expression of pro-inflammatory cytokines and factors related to necroptosis in the hypothalamus, pituitary gland, and adrenal gland were increased. As an inhibitor of necroptosis, necrostatin-1 (Nec-1) inhibited necroptosis through decreasing mRNA expression of necroptosis signal factors in the HPA axis. Nec-1 also reduced the mRNA levels of pro-inflammatory cytokines in the HPA axis. Meanwhile, the activation of the HPA axis was inhibited by Nec-1 as shown by the decrease of plasma CRH and ACTH concentrations and the mRNA expressions of hypothalamus CRH and pituitary POMC. These findings indicated that as a result of necroptosis, the HPA axis was activated by DON. In light of these findings, necroptosis could be considered as an intervention target that alleviates HPA axis activation and stress responses.

Insights of early feeding regime supplemented with glutamine and various levels of omega-3 in broiler chickens: growth performance, muscle building, antioxidant capacity, intestinal barriers health and defense against mixed Eimeria spp infection

Early nutritional management approach greatly impacts broilers' performance and resistance against coccidiosis. The current study explored the impact of post-hatch feeding with a combination of glutamine (Glut) and different levels of omega-3 on broiler chickens' growth performance, muscle building, intestinal barrier, antioxidant ability and protection against avian coccidiosis. A total of six hundred Cobb 500 was divided into six groups: first group (fed basal diet and unchallenged (control) and challenged (negative control, NC) groups were fed a basal diet without additives, and the other groups were infected with Eimeria spp and supplemented with 1.5% Glut alone or with three different levels of omega-3 (0.25, 0.5 and 1%) during the starter period. Notable improvement in body weight gain was observed in the group which fed basal diet supplemented with glut and 1% omega 3 even after coccidia infection (increased by 25% compared challenged group) while feed conversion ratio was restored to control. Myogeneis was enhanced in the group supplemented with Glut and omega-3 (upregulation of myogenin, MyoD, mechanistic target of rapamycin kinase and insulin like growth factor-1 and downregulating of myostatin genes). Groups supplemented with Glut and higher levels of omega-3 highly expressed occluding, mucin-2, junctional Adhesion Molecule 2, b-defensin-1 and cathelicidins-2 genes. Group fed 1% Glut + omega-3 showed an increased total antioxidant capacity and glutathione peroxidase and super oxide dismutase enzymes activities with reduced levels of malondialdehyde, reactive oxygen species and H2O2. Post-infection, dietary Glut and 1% omega-3 increased intestinal interleukin-10 (IL) and secretory immunoglobulin-A and serum lysozyme, while decreased the elevated inflammatory mediators comprising interleukin IL-6, tumor necrosis factor-alpha, nitric oxide (NO) and inducible NO synthase. Fecal oocyst excretion and lesions score severity were lowered in the group fed 1% Glut and omega 3. Based on these findings, dietary Glut and omega-3 supplementation augmented restored overall broilers' performance after coccidial challenge.

Pyrroloquinoline Quinone Alleviates Intestinal Inflammation and Cell Apoptosis via the MKK3/6-P38 Pathway in a Piglet Model

This study investigates the underlying mechanism through which dietary supplementation of pyrroloquinoline quinone disodium (PQQ) alleviates intestinal inflammation and cell apoptosis in piglets challenged with lipopolysaccharide (LPS). Seventy-two barrows were divided into three groups: control (CTRL), LPS challenged (LPS), and LPS challenged with PQQ supplementation (PQQ + LPS). On d 7, 11, and 14, piglets received intraperitoneal injections of LPS or 0.9% of NaCl (80 μg/kg). After a 4 h interval following the final LPS injection on d 14, blood samples were obtained, and all piglets were euthanized for harvesting jejunal samples. The results showed that dietary supplementation of PQQ improved the damage of intestinal morphology, increased the down-regulated tight junction proteins, and reduced the increase of serum diamine oxidase activity, the intestinal fatty acid binding protein, and TNF-α levels in piglets challenged with LPS (p < 0.05). The proteomics analysis revealed a total of 141 differentially expressed proteins (DEPs), consisting of 64 up-regulated DEPs and 77 down-regulated DEPs in the PQQ + LPS group compared to the LPS group. The KEGG pathway analysis indicated enrichment of the tight junction pathway and the apoptosis pathway (p < 0.05). Compared to the LPS group, the piglets in the PQQ + LPS group had increased levels of Bcl-2 protein, reduced positive apoptosis signals, and a decrease in the abundance of MKK 3/6 and p-p38 proteins (p < 0.05). In conclusion, dietary supplementation of PQQ could alleviate jejunal inflammatory damage and cell apoptosis in piglets challenged with LPS through the MKK3/6-p38 signaling pathway.

Flaxseed Oil Attenuates Intestinal Damage by Regulating Ferroptosis Signaling Pathway Following LPS Challenge in Piglets

SCOPE

Ferroptosis has been demonstrated to play an important role in various tissue injuries and diseases. Flaxseed oil (FO) has been proven to have benefits for intestinal health. This study aims to explore whether FO relieved lipopolysaccharide (LPS)-induced intestinal injury through modulating ferroptosis signaling pathway.

METHODS AND RESULTS

A total of 120 weaned piglets are fed diets with 3% soybean oil (SO) or 3% FO for 4 weeks. At the end of the trial, 24 piglets selected from two dietary treatment groups are used in a 2 × 2 factorial design with oil treatment (3% SO versus 3% FO) and LPS challenge (saline versus LPS). At 4 h postinjection with LPS, 24 piglets are slaughtered and intestinal samples are collected. FO improves growth performance of pigs. After LPS treatment, FO mitigates intestinal morphological damage and functional damage. Notably, FO reverses the typical ultra-morphology and biochemical indexes of ferroptosis involving glutathione, malondialdehyde, and 4-hydroxynonenal contents. Mechanistically, FO ameliorates the changes on mRNA or protein abundance of key ferroptosis signals including transferrin receptor protein 1 (TFR1), recombinant iron responsive element binding protein 2 (IREB2), FTL, HSPB1, ferritin heavy chain 1 (FTH1), ferroportin 1 (FPN1), SLC7A11, solute carrier family 3 member 2 (SLC3A2), glutathione peroxidase 4 (GPX4), and arachidonate-15-lipoxygenase (ALOX15).

CONCLUSIONS

FO improves growth performance and mitigates intestinal structural and functional damage, which is involved in regulating ferroptosis signaling pathway.

Maternal docosahexaenoic acid supplementation during lactation improves exercise performance, enhances intestinal glucose absorption and modulates gut microbiota in weaning offspring mice

Introduction

Intestinal dysfunction induced by weaning stress is common during breastfeeding period. Docosahexaenoic acid (DHA) is well known for promoting visual and brain development, but its effects on early intestinal development remain unknown. This study investigated the impact of maternal DHA supplementation during lactation on intestinal glucose absorption and gut microbiota in weaning offspring mice.

Materials and methods

Dams were supplemented with vehicle (control), 150 mg/(kg body weight · day) DHA (L-DHA), or 450 mg/(kg body weight · day) DHA (H-DHA) throughout lactation by oral administration. After weaning, pups were randomly divided into three groups for athletic analysis, microbial and proteomic analysis, biochemical analysis, 4-deoxy-4-fluoro-D-glucose (4-FDG) absorption test, and gene expression quantitation of glucose transport-associated proteins and mTOR signaling components.

Results

The H-DHA group exhibited enhanced grip strength and prolonged swimming duration compared to the control group. Additionally, there were significant increases in jejunal and ileal villus height, and expanded surface area of jejunal villi in the H-DHA group. Microbial analyses revealed that maternal DHA intake increased the abundance of beneficial gut bacteria and promoted metabolic pathways linked to carbohydrate and energy metabolism. Proteomic studies indicated an increased abundance of nutrient transport proteins and enrichment of pathways involved in absorption and digestion in the H-DHA group. This group also showed higher concentrations of glucose in the jejunum and ileum, as well as elevated glycogen levels in the liver and muscles, in contrast to lower glucose levels in the intestinal contents and feces compared to the control group. The 4-FDG absorption test showed more efficient absorption after oral 4-FDG gavage in the H-DHA group. Moreover, the expressions of glucose transport-associated proteins, GLUT2 and SGLT1, and the activation of mTOR pathway were enhanced in the H-DHA group compared to the control group. The L-DHA group also showed similar but less pronounced improvements in these aspects relative to the H-DHA group.

Conclusion

Our findings suggested that maternal DHA supplementation during lactation improves the exercise performance, enhances the intestinal glucose absorption by increasing the expressions of glucose transporters, and beneficially alters the structure of gut microbiome in weaning offspring mice.

Effects of Crude Extract of Glycyrrhiza Radix and Atractylodes macrocephala on Immune and Antioxidant Capacity of SPF White Leghorn Chickens in an Oxidative Stress Model

The natural edible characteristics of Chinese herbs have led more and more people to study them as an alternative product to antibiotics. In this study, crude extracts of Glycyrrhiza radix and Atractylodes macrocephala (abbreviated as GRAM) with glycyrrhizic acid content not less than 0.2 mg/g were selected to evaluate the effects of GRAM on the immune and antioxidant capacity of model animals. Thirty 21-day-old male Leghorn chickens were weighed and randomly assigned to one of three groups of ten animals each. The treatments comprised a control group (CON), in which saline was injected at day 31, day 33, and day 35, an LPS-treated group (LPS), in which LPS (0.5 mg/kg of BW) was injected at day 31, day 33, and day 35, and finally a GRAM and LPS-treated group, (G-L) in which a GRAM-treated diet (at GRAM 2 g/kg) was fed from day 21 to day 35 with LPS injection (0.5 mg/kg of BW) at day 31, day 33, and day 35. The results of diarrhea grade and serum antioxidant measurement showed that the LPS group had obvious diarrhea symptoms, serum ROS and MDA were significantly increased, and T-AOC was significantly decreased. The oxidative stress model of LPS was successfully established. The results of immune and antioxidant indexes showed that feeding GRAM significantly decreased levels of the pro-inflammatory factors TNF-α, IL-1β, and IL-6 (p < 0.05) and significantly increased levels of the anti-inflammatory factors IL-4 and IL-10 and levels of the antioxidant enzymes GSH-Px and CAT (p < 0.05). GRAM resisted the influence of LPS on ileum morphology, liver, and immune organs and maintained normal index values for ileum morphology, liver, and immune organs. In summary, this study confirmed the antidiarrheal effect of GRAM, which improved the immune and antioxidant capacity of model animals by regulating inflammatory cytokine levels and antioxidant enzyme activity in poultry.

Microencapsulate Probiotics (MP) Promote Growth Performance and Inhibit Inflammatory Response in Broilers Challenged with Salmonella typhimurium

Antibiotic-resistant bacteria are prevalent in husbandry around the world due to the abuse of antibiotic growth promoters (AGPs); therefore, it is necessary to find alternatives to AGPs in animal feed. Among all the candidates, probiotics are promising alternatives to AGPs against Salmonella infection. The anti-Salmonella effects of three probiotic strains, namely, Lactobacillus crispatus 7-4, Lactobacillus johnsonii 3-1, and Pediococcus acidilactici 20-1, have been demonstrated in our previous study. In this study, we further obtained the alginate beads containing compound probiotics, namely, microencapsulate probiotics (MP), and evaluated its regulatory effect on the health of broilers. We incubated free and microencapsulate probiotics in simulated gastric and intestinal juice for 2 h, and the results showed that compared to free probiotics, encapsulation increased tolerance of compound probiotics in the simulated gastrointestinal condition. We observed that the application of probiotics, especially MP, conferred protective effects against Salmonella typhimurium (S.Tm) infection in broilers. Compared to the S.Tm group, the MP could promote the growth performance (p < 0.05) and reduce the S.Tm load in intestine and liver (p < 0.05). In detail, MP pretreatment could modulate the cecal microflora and upregulate the relative abundance of Lactobacillus and Enterobacteriaceae. Besides, MP could reduce the inflammation injury of the intestine and liver, reduce the pro-inflammatory cytokines (IL-6, TNF-α, IL-1β) expression, and induce of anti-inflammatory cytokine (IL-10) expression. Furthermore, MP could inhibit NLRP3 pathway in ileum, thereby attenuating S.Tm-induced inflammation. In conclusion, MP could be a new feeding supplementation strategy to substitute AGPs in poultry feeding.

Probiotic Roles of Clostridium butyricum in Piglets: Considering Aspects of Intestinal Barrier Function

China, as the global leader in pork production and consumption, is faced with challenges in ensuring sustainable and wholesome growth of the pig industry while also guaranteeing meat food safety amidst the ban on antibiotics usage in animal feed. The focus of the pig industry lies in guaranteeing piglet health and enhancing overall production performance through nutrition regulation. Clostridium butyricum (C. butyricum), a new type of probiotic, possesses characteristics such as heat resistance, acid resistance, and bile-salt tolerance, meaning it has potential as a feed additive. Previous studies have demonstrated that C. butyricum has a probiotic effect on piglets and can serve as a substitute for antibiotics. The objective of this study was to review the probiotic role of C. butyricum in the production of piglets, specifically focusing on intestinal barrier function. Through this review, we explored the probiotic effects of C. butyricum on piglets from the perspective of intestinal health. That is, C. butyricum promotes intestinal health by regulating the functions of the mechanical barrier, chemical barrier, immune barrier, and microbial barrier of piglets, thereby improving the growth of piglets. This review can provide a reference for the rational utilization and application of C. butyricum in swine production.

Modulation of pectin on intestinal barrier function via changes in microbial functional potential and bile acid metabolism

Weaning is one of the major factors that cause stress and intestinal infection in infants and in young animals due to an immature intestine and not fully developed immune functions. Pectin (PEC), a prebiotic polysaccharide, has attracted considerable attention in intestinal epithelial signaling and function via modulation of the microbial community. A total of 16 weaned piglets (21-d-old) were randomly assigned into two groups: control group and PEC group. Supplementation of 5% pectin improved intestinal mucosal barrier function by modulating the composition of the bile acid pool in piglets. Specifically, piglets in PEC group had less serum D-lactate content and alkaline phosphatase activity. In the ileum, dietary pectin increased the number of crypt PAS/AB-positive goblet cells and the mRNA expressions of MUC2, ZO-1, and Occludin. Piglets in PEC group displayed a decreased abundance of Enterococcus (2.71 vs. 65.92%), but the abundances of Lactobacillus (30.80 vs. 7.93%), Streptococcus (21.41 vs. 14.81%), and Clostridium_sensu_stricto_1 (28.34 vs. 0.01%) were increased. Elevated concentrations of bile acids especially hyocholic acid species (HCAs) including HCA, HDCA, and THDCA were also observed. Besides, correlation analysis revealed that dietary pectin supplementation may have beneficial effects through stimulation of the crosstalk between gut microbes and bile acid synthesis within the enterohepatic circulation. Thus, dietary pectin supplementation exhibited a further positive effect on the healthy growth and development of weaned piglets. These findings suggest pectin supplementation as the prebiotic is beneficial for gut health and improvement of weaned stress via regulating microbiota and bile acid metabolism.

Glutamine attenuates bisphenol A-induced intestinal inflammation by regulating gut microbiota and TLR4-p38/MAPK-NF-κB pathway in piglets

Bisphenol A (BPA), as a kind of widely exerted environmental hazardous material, brings toxicity to both humans and animals. This study aimed to investigate the role of glutamine (Gln) in intestinal inflammation and microbiota in BPA-challenged piglets. Thirty-two piglets were randomly divided into four groups according to 2 factors including BPA (0 vs. 0.1%) and Gln (0 vs. 1%) supplemented in basal diet for a 42-day feeding experiment. The results showed BPA exposure impaired piglet growth, induced intestinal inflammation and disturbed microbiota balance. However, dietary Gln supplementation improved the growth performance, while decreasing serum pro-inflammatory cytokine levels in BPA-challenged piglets. In addition, Gln attenuated intestinal mucosal damage and inflammation by normalizing the activation of toll-like receptor 4 (TLR4)-p38/MAPK-nuclear factor-kappa B (NF-κB) pathway caused by BPA. Moreover, dietary Gln supplementation decreased the abundance of Actinobacteriota and Proteobacteria, and attenuated the decreased abundance of Roseburia, Prevotella, Romboutsia and Phascolarctobacterium and the content of short-chain fatty acids in cecum contents caused by BPA exposure. Moreover, there exerted potential relevance between the gut microbiota and pro-inflammatory cytokines and cecal short-chain fatty acids. In conclusion, Gln is critical nutrition for attenuating BPA-induced intestinal inflammation, which is partially mediated by regulating microbial balance and suppressing the TLR4/p38 MAPK/NF-κB signaling.

Dietary Chito-oligosaccharide attenuates LPS-challenged intestinal inflammation via regulating mitochondrial apoptotic and MAPK signaling pathway

To investigate the regulatory effects of Chito-oligosaccharide (COS) on the anti-oxidative, anti-inflammatory, and MAPK signaling pathways. A total of 40 28-day-old weaned piglets were randomly allotted to 4 equal groups [including the control group, lipopolysaccharide (LPS) group, COS group, and COS*LPS group]. On the morning of d 14 and 21, piglets were injected with saline or LPS. At 2 h post-injection, whole blood samples were collected on d 14 and 21, and small intestine and liver samples were collected and analyzed on d 21. The results showed that COS inhibited the LPS-induced increase of malondialdehyde (MDA) concentration and hepatic TNF-α cytokines. COS significantly increased the serum total antioxidant capability (T-AOC) value on d 14, and total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX) activities in both serum and liver on d 21. Furthermore, it increased hepatic catalase (CAT) activity. COS also increased the LPS-induced decrease in serum IgG concentrations. Immunohistochemical analysis results showed that COS significantly increased the jejunal and ileal Caspase 3, and ileal CD4+ values challenged by LPS. Dietary COS decreased the LPS-induced jejunal and ileal BAX and CCL2 mRNA levels, markedly decreased ileal COX2 and SOD1 mRNA levels, while increasing ileal iNOS. Furthermore, COS significantly increased the LPS-induced jejunal and ileal p-P38 and MyD88, as well as jejunal P38, while it effectively suppressed jejunal JNK1, and jejunal and ileal JNK2, p-JNK1, and p-JNK2 protein expressions. These results demonstrated that COS could be beneficial by attenuating LPS-challenged intestinal inflammation via regulating mitochondrial apoptotic and MAPK signaling pathways.

Effects of a veterinary gastrointestinal low-fat diet on fecal characteristics, metabolites, and microbiota concentrations of adult dogs treated with metronidazole

Antibiotics are known to cause loose stools, disrupt the fecal microbiota, and alter fecal bile acid (BA) profiles of dogs. Recovery may be aided by diet, but little research has been conducted. The objective of this study was to determine how a veterinary low-fat diet affected the fecal characteristics, metabolites, BA, and microbiota of dogs receiving antibiotics. Twenty-four healthy adult dogs [7.38 ± 1.95 yr; 7.67 ± 0.76 kg body weight (BW)] were used in an 8-wk completely randomized design study. During a 2-wk baseline, all dogs were fed a leading grocery brand diet (GBD). Over the next 2 wk, dogs were fed GBD and received metronidazole orally (20 mg/kg BW twice daily). At week 4, dogs were randomly allotted to one of two treatments [GBD or Blue Buffalo Natural Veterinary Diet GI Gastrointestinal Support Low-Fat (BB)] and fed for 4 wk. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter content, and metabolite and BA concentrations. Fecal microbiota populations were analyzed using 16S rRNA gene amplicon sequencing and qPCR-based dysbiosis index (DI). All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of treatment, time, and treatment*time and significance set at P < 0.05. Metronidazole increased (P < 0.0001) fecal scores (looser stools), reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations, increased primary BA concentrations, and decreased secondary BA concentrations. Metronidazole also reduced fecal bacterial alpha diversity, altered the abundance of 58 bacterial genera, and increased DI. During antibiotic recovery, changes in fecal pH, dry matter percentage, and metabolite and immunoglobulin A concentrations were altered (P < 0.05) by diet. Fecal BA concentrations recovered quickly for all dogs. Change in lithocholic acid was affected (P < 0.0001) by diet, but other BA were not. Recovery of over 25 bacterial genera was impacted by diet (P < 0.05). While many bacterial taxa returned to baseline levels after 4 wk, others did not fully recover. DI and bacterial alpha diversity measures recovered quickly for all dogs but were not impacted by diet. In conclusion, metronidazole drastically altered the fecal microbiota and metabolites of dogs. While most variables returned to baseline by week 8, diet may be used to aid in recovery.

Effects of Enterotoxigenic Escherichia coli Challenge on Jejunal Morphology and Microbial Community Profiles in Weaned Crossbred Piglets

Pathogenic enterotoxigenic Escherichia coli (ETEC) is a major cause of bacterial diarrhea in weaning piglets, which are vulnerable to changes in environment and feed. This study aimed to determine the effects of the ETEC challenge on piglet growth performance, diarrhea rate, jejunal microbial profile, jejunal morphology and goblet cell distribution. A total of 13 piglets from one litter were selected on postnatal day 21 and assigned to treatments with or without ETEC challenge at 1 × 108 CFUs, as ETEC group or control group, respectively. On postnatal day 28, samples were collected, followed by the detection of serum biochemical indexes and inflammatory indicators, HE staining, PAS staining and 16S rDNA gene amplicon sequencing. Results showed that the growth performance decreased, while the diarrhea rate increased for the ETEC group. The jejunum is the main segment of the injured intestine during the ETEC challenge. Compared with the control, the ETEC group displayed fewer goblet cells in the jejunum, where goblet cells are more distributed at the crypt and less distributed at the villus. In addition, ETEC piglets possessed higher abundances of the genus Desulfovibrio, genus Oxalobacter and genus Peptococus and lower abundances of the genus Prevotella 2, genus Flavonifractor and genus Blautra. In terms of alpha diversity, Chao 1 and observed features indexes were both increased for the ETEC group. Our study provides insights into jejunal histopathological impairment and microbial variation in response to ETEC infection for weaned piglets and is a valuable reference for researchers engaged in animal health research to select stress models.

Quercetin Ameliorates Deoxynivalenol-Induced Intestinal Injury and Barrier Dysfunction Associated with Inhibiting Necroptosis Signaling Pathway in Weaned Pigs

Quercetin (Que) is a flavonol compound found in plants, which has a variety of biological activities. Necroptosis, a special form of programmed cell death, plays a vital role in the development of many gastrointestinal diseases. This study aimed to explore whether Que could attenuate the intestinal injury and barrier dysfunction of piglets after deoxynivalenol (DON) exposure through modulating the necroptosis signaling pathway. Firstly, twenty-four weaned piglets were used in a 2 × 2 factorial design and the main factors, including Que (basal diet or diet supplemented with 100 mg/kg Que) and DON exposure (control feed or feed contaminated with 4 mg/kg DON). After feeding for 21 d, piglets were killed for samples. Next, the intestinal porcine epithelial cell line (IPEC-1) was pretreated with or without Que (10 μmol/mL) in the presence or absence of a DON challenge (0.5 μg/mL). Dietary Que increased the body weight, average daily gain, and average daily feed intake (p < 0.05) through the trial. Que supplementation improved the villus height, and enhanced the intestinal barrier function (p < 0.05) indicated by the higher protein expression of occludin and claudin-1 (p < 0.05) in the jejunum of the weaned piglets after DON exposure. Dietary Que also down-regulated the protein abundance of total receptor interacting protein kinase 1 (t-RIP1), phosphorylated RIP1 (p-RIP1), p-RIP3, total mixed lineage kinase domain-like protein (t-MLKL), and p-MLKL (p < 0.05) in piglets after DON exposure. Moreover, Que pretreatment increased the cell viability and decreased the lactate dehydrogenase (LDH) activity (p < 0.05) in the supernatant of IPEC-1 cells after DON challenge. Que treatment also improved the epithelial barrier function indicated by a higher transepithelial electrical resistance (TEER) (p < 0.001), lower fluorescein isothiocyanate-labeled dextran (FD4) flux (p < 0.001), and better distribution of occludin and claudin-1 (p < 0.05) after DON challenge. Additionally, pretreatment with Que also inhibited the protein abundance of t-RIP1, p-RIP1, t-RIP3, p-RIP3, t-MLKL, and p-MLKL (p < 0.05) in IPEC-1 cells after DON challenge. In general, our data suggest that Que can ameliorate DON-induced intestinal injury and barrier dysfunction associated with suppressing the necroptosis signaling pathway.

Effect of Different Dietary Lipid Sources on Growth Performance, Nutrient Digestibility, and Intestinal Health in Weaned Pigs

To investigate the effects of lipid sources on growth performance and intestinal health, 72 weaned pigs were randomly allocated to three treatments. Pigs were fed with a corn-soybean meal diet containing 2% soybean oil (SO), or fish-palm-rice oil mixture (FPRO), or coconut-palm-rice oil mixture (CPRO). The trial lasted for 28 days; blood and intestinal tissue samples were collected. The results showed that the crude fat digestibility of the FPRO group was higher than that of the SO and CPRO groups (p < 0.05). The FPRO group also had higher digestibility of dry matter, ash, and gross energy than the SO group (p < 0.05); compared to the SO group, the serum interlukin-6 (IL-6) concentration was decreased. Interestingly, the FPRO and CPRO groups had higher villus height than the SO group in the jejunum and ileum, respectively (p < 0.05). Moreover, the FPRO group had higher Lactobacillus abundance than the SO group in the colon and cecum (p < 0.05). Importantly, the expression levels of tight junction protein ZO-1, Claudin-1, and Occludin in the duodenal and ileal mucosa were higher in the FPRO group than in the SO and CPRO groups (p < 0.05). The expression levels of nutrient transporters such as the CAT-1, PepT1, FATP1, and SGLT1 were higher in the FPRO group than in the SO group (p < 0.05). The improved digestibility and intestinal epithelium functions, as well as the reduced inflammatory cytokines, in the FPRO and CPRO group suggest that a mixed lipid source such as the FPRO deserves further attention.

Selenium-enriched Cardamine violifolia protects against sepsis-induced intestinal injury by regulating mitochondrial fusion in weaned pigs

Sepsis is a life-threatening organ dysfunction caused by the dysregulated response of the host to an infection, and treatments are limited. Recently, a novel selenium source, selenium-enriched Cardamine violifolia (SEC) has attracted much attention due to its anti-inflammatory and antioxidant properties, but little is known about its role in the treatment of sepsis. Here, we found that SEC alleviated LPS-induced intestinal damage, as indicated by improved intestinal morphology, and increased disaccharidase activity and tight junction protein expression. Moreover, SEC ameliorated the LPS-induced release of pro-inflammatory cytokines, as indicated by decreased IL-6 level in the plasma and jejunum. Moreover, SEC improved intestinal antioxidant functions by regulating oxidative stress indicators and selenoproteins. In vitro, TNF-α-challenged IPEC-1 cells were examined and showed that selenium-enriched peptides, which are the main functional components extracted from Cardamine violifolia (CSP), increased cell viability, decreased lactate dehydrogenase activity and improved cell barrier function. Mechanistically, SEC ameliorated LPS/TNF-α-induced perturbations in mitochondrial dynamics in the jejunum and IPEC-1 cells. Moreover, CSP-mediated cell barrier function is primarily dependent on the mitochondrial fusion protein MFN2 but not MFN1. Taken together, these results indicate that SEC mitigates sepsis-induced intestinal injury, which is associated with modulating mitochondrial fusion.

Protective effects of polydatin on ileum injury in mice exposed to aflatoxin B1

Aflatoxin B1 (AFB1) is an extremely hazardous food/feed pollutant, posing a serious threat to health of human and animals. Particularly, exposure to AFB1 provokes enterocytes oxidative stress and inflammation, which lead to intestinal damage. Polydatin (PD), a stilbenoid glucoside, is known to possess antioxidant and anti-inflammatory properties and is being investigated for use in various disorders. The present study was intended at investigating the protective efficacy of polydatin against AFB1-induced ileum damage in mice. Kunming male mice received oral gavage of AFB1 (300 μg/kg) and PD (100 mg/kg) for 18 days. The results showed that mice exposed to AFB1 exhibited the impaired morphology, the suppressed disaccharidase activities, the down-regulated mRNA expressions of tight junction protein genes, oxidative stress, inflammation and the up-regulated mRNA expressions of genes related to mitophagy in the ileum, whereas PD treatment reversed the AFB1-induced disruption of ileal structure, digestion, barrier function, redox and immune status. The findings of the present study suggested that polydatin may have a potential benefit in preventing AFB1-induced ileum damage.

The synbiotic mixture of lactulose and Bacillus coagulans protects intestinal barrier dysfunction and apoptosis in weaned piglets challenged with lipopolysaccharide

BACKGROUND

Lactulose as an effective prebiotic protects intestinal mucosal injury. Bacillus coagulans is widely used in feed additives because of its ability to promote intestinal health. Our previous study suggests that the combination of lactulose and Bacillus coagulans may be a good candidate as alternative for antibiotic growth promoters. However, the in vivo effects of lactulose and Bacillus coagulans on growth and intestinal health under immune challenge in piglets remains unclear. The objective of this study is to explore the protective effects of synbiotic containing lactulose and Bacillus coagulans on the intestinal mucosal injury and barrier dysfunction under immune challenge in weaned piglets.

METHODS

Twenty four weaned piglets were assigned to 4 groups. Piglets in the CON_-saline and LPS_-LPS group were fed the basal diet, while others were fed either with chlortetracycline (CTC) or synbiotic mixture of lactulose and Bacillus coagulans for 32 d before injection of saline or lipopolysaccharide (LPS). Piglets were sacrificed 4 h after LPS injection to collect samples to determine intestinal morphology, integrity and barrier functions as well as relative genes and proteins.

RESULTS

Our data showed that no differences were observed in the growth performance of the four test groups. LPS injection induced higher serum diamine oxidase activities, D-lactic acid levels, and endotoxin status, lower villus height and ratio of villus height to crypt depth, greater mRNA and lower protein expression related tight junction in both jejunum and ileum. In addition, a higher apoptosis index, and protein expression of Bax and caspase-3 were also observed in the LPS challenge group. Interestingly, dietary synbiotic mixture with lactulose and Bacillus coagulans protected against LPS-induced intestinal damage, barrier dysfunction and higher apoptosis as well as CTC.

CONCLUSIONS

Our data suggest that dietary supplementation of synbiotic mixture with lactulose and Bacillus coagulans showed resilience to LPS-induced intestinal morphological damage, barrier dysfunction and aggressive apoptosis in piglets as well as the protective effects of CTC. These results indicate that synbiotic mixture of lactulose and Bacillus coagulans showed beneficial effects on performance and resilience to acute immune stress in weaned piglets.

New Insights of Biological Functions of Natural Polyphenols in Inflammatory Intestinal Diseases

The intestine is critically crucial for nutrient absorption and host defense against exogenous stimuli. Inflammation-related intestinal diseases, including enteritis, inflammatory bowel disease (IBD), and colorectal cancer (CRC), are heavy burdens for human beings due to their high incidence and devastating clinical symptoms. Current studies have confirmed that inflammatory responses, along with oxidative stress and dysbiosis as critical pathogenesis, are involved in most intestinal diseases. Polyphenols are secondary metabolites derived from plants, which possess convincible anti-oxidative and anti-inflammatory properties, as well as regulation of intestinal microbiome, indicating the potential applications in enterocolitis and CRC. Actually, accumulating studies based on the biological functions of polyphenols have been performed to investigate the functional roles and underlying mechanisms over the last few decades. Based on the mounting evidence of literature, the objective of this review is to outline the current research progress regarding the category, biological functions, and metabolism of polyphenols within the intestine, as well as applications for the prevention and treatment of intestinal diseases, which might provide ever-expanding new insights for the utilization of natural polyphenols.

Effects of dietary supplementation with a carvacrol-cinnamaldehyde-thymol blend on growth performance and intestinal health of nursery pigs

BACKGROUND

Stress, herd transfer, and food changes experienced by nursery and fattening pigs can lead to reduced performance, reduced digestion and absorption, and impaired intestinal health. Given the role of essential oils in relieving stress and improving animal welfare, we hypothesized that essential oils may improve pig performance via promoting gut health and gut homeostasis laid by EOs supplementation during nursery continuously impacts performance in fattening pigs.

RESULTS

A total of 100 piglets (Landrace × Large White; weighted 8.08 ± 0.34 kg, weaned at d 28) were randomly selected and divided into 2 treatments: (1) basal diet (Con); (2) basal diet supplement with 0.1% complex essential oils (CEO). The experiment period was 42 days. Then weaned piglets' growth performance and indications of intestinal health were assessed. Compared to the Con group, dietary supplemented CEO enhanced BW at 14 d (P < 0.05), and increased ADG during 1 ~ 14 d and 1 ~ 42 d (P < 0.05). Furthermore, CEO group had lower FCR during 1 ~ 42 d (P < 0.05). The CEO group also showed higher VH and VH:CD in duodenum and ileum (P < 0.05). Additionally, dietary CEO supplementation improved gut barrier function, as manifested by increased the mRNA expression of tight-junction protein and decreased serum DAO, ET and D-LA levels (P < 0.05). Finally, CEO supplementation alleviated gut inflammation, increased the activity of digestive enzymes. Importantly, piglets supplemented with CEOs during nursery also had better performance during fattening, suggesting that the establishment of intestinal health will also continuously affect subsequent digestion and absorption capacity. In short, dietary supplemented CEO improved performance and gut health via modulating increased intestine absorptive area, barrier integrity, digestive enzyme activity, and attenuating intestine inflammation. Meanwhile, essential oil supplementation during the nursery period also had a favorable effect on the performance of growing pigs.

CONCLUSIONS

Therefore, the strategy of adding CEO to pig diets as a growth promoter and enhancing intestinal health is feasible.

Evaluation of tributyrin supplementation in milk replacer on diarrhoea occurrence in pre-weaning Holstein calves

Neonatal calf diarrhoea is one of the most important health challenges in cattle herds causing substantial economic losses and antimicrobial use. Due to the raising problem of antimicrobial resistance, effective alternatives are urgently required, in line with European policies. The aim of this study was to evaluate the effect of tributyrin supplementation in milk replacer on diarrhoea, performance and metabolic status in preweaning Holstein calves. Twelve newborn calves, after colostrum administration, were randomly allotted in two experimental groups for 42 days: control (CTRL) fed milk replacer, tributyrin (TRIB) fed milk replacer supplemented with 0.3% of liquid tributyrin on milk powder weight. Calves BW was recorded on a weekly basis from day 7 to day 42, and feed intake was recorded daily to calculate zootechnical performance. Faecal consistency was assessed daily through the faecal score (0-3 scale; considering diarrhoea moderate = 2 and severe = 3). Faecal samples were collected weekly from rectal ampulla for microbiological analysis by plate counting method evaluating the number of total bacteria, lactic acid bacteria and coliform bacteria. On day 0 and day 42, individual blood samples were collected from jugular vein for metabolic profile analysis. Serum samples of day 42 were also evaluated for the antioxidant barrier using a colorimetric test, while glucagon-like peptide 2 and diamine oxidase concentrations were measured through immunoenzymatic assays. Tributyrin supplementation did not influence the zootechnical performance of calves over 42 days of trial. Diarrhoea frequency was significantly lower in TRIB compared to CTRL group (27.91 and 38.37%; P < 0.01) considering the whole experimental period. In particular, the major effect was observed for moderate diarrhoea in TRIB group that showed a significantly reduced frequency compared to CTRL (P < 0.01) thus suggesting a preventive effect of tributyrin. Faecal total bacterial, lactic acid and coliform bacteria counts did not show differences between groups. Urea serum concentrations tended to be lower in TRIB compared to CTRL, indicating an efficient utilisation of dietary protein. Antioxidant barrier and glucagon-like peptide 2 were comparable between CTRL and TRIB on day 42. Diamine oxidase concentrations were significantly decreased in TRIB compared to CTRL group after 42 days of trial (P < 0.01), suggesting a higher gut epithelial integrity probably due to lower diarrhoea frequency and the nourish effect of tributyrin on enterocytes. In conclusion, tributyrin could be considered as a valuable bioactive feed additive to decrease the neonatal diarrhoea occurrence and support intestinal integrity in preweaning calves.

Potential of Capric Acid in Neurological Disorders: An Overview

To solve the restrictions of a classical ketogenic diet, a modified medium-chain triglyceride diet was introduced which required only around 60% of dietary energy. Capric acid (CA), a small molecule, is one of the main components because its metabolic profile offers itself as an alternate source of energy to the brain in the form of ketone bodies. This is possible with the combined capability of CA to cross the blood-brain barrier and achieve a concentration of 50% concentration in the brain more than any other fatty acid in plasma. Natural sources of CA include vegetable oils such as palm oil and coconut oil, mammalian milk and some seeds. Several studies have shown that CA has varied action on targets that include AMPA receptors, PPAR-γ, inflammatory/oxidative stress pathways and gut dysbiosis. Based on these lines of evidence, CA has proved to be effective in the amelioration of neurological diseases such as epilepsy, affective disorders and Alzheimer's disease. But these studies still warrant more pre-clinical and clinical studies that would further prove its efficacy. Hence, to understand the potential of CA in brain disease and associated comorbid conditions, an advance and rigorous molecular mechanistic study, apart from the reported in-vitro/in-vivo studies, is urgently required for the development of this compound through clinical setups.

Role of functional fatty acids in modulation of reproductive potential in livestock

Fatty acids are not only widely known as energy sources, but also play important roles in many metabolic pathways. The significance of fatty acids in modulating the reproductive potential of livestock has received greater recognition in recent years. Functional fatty acids and their metabolites improve follicular development, oocyte maturation and embryo development, as well as endometrial receptivity and placental vascular development, through enhancing energy supply and precursors for the synthesis of their productive hormones, such as steroid hormones and prostaglandins. However, many studies are focused on the impacts of individual functional fatty acids in the reproductive cycle, lacking studies involved in deeper mechanisms and optimal fatty acid requirements for specific physiological stages. Therefore, an overall consideration of the combination and synergy of functional fatty acids and the establishment of optimal fatty acid requirement for specific stages is needed to improve reproductive potential in livestock.

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 1β (IL-1β) 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.

Advances in the Clinical Application of Histamine and Diamine Oxidase (DAO) Activity: A Review

The serum level of diamine oxidase (DAO) reflects the integrity and maturation of the small intestinal mucosa. This measure is important in diagnosing various diseases, including chronic urticaria tachyphylaxis, multiple organ dysfunction syndrome, preterm abortion, and migraine. This review aimed to summarize the findings of previous studies on the changes in DAO levels in diverse diseases and the application of this enzyme in the clinical setting, as well as the roles of this enzyme under physiological and pathological conditions. The advances in the mechanism and clinical application of DAO presented in this review will contribute to a better understanding of this enzyme and open up new and broader perspectives for future basic research and clinical applications.

Influence of dietary n-3 long-chain fatty acids on microbial diversity and composition of sows' feces, colostrum, milk, and suckling piglets' feces

Introduction

Very little is known about the impact of n-3 long-chain fatty acids (n-3 LCFAs) on the microbiota of sows and their piglets. The aim of this study was to evaluate the effect of n-3 LCFA in sow diets on the microbiota composition of sows' feces, colostrum, and milk as well as that of piglets' feces.

Methods

Twenty-two sows were randomly assigned to either a control or an n-3 LCFA diet from service to weaning. Sows' and piglets' performance was monitored. The gestating and lactating sows' microbiomes in feces, colostrum, and milk were characterized by 16s ribosomal RNA gene sequencing. The fecal microbiome from the two lowest (>800 g) and the two highest birth weight piglets per litter was also characterized, and the LPS levels in plasma were analyzed at weaning.

Results and Discussion

n-3 LCFA increased microbiota alpha diversity in suckling piglets' and gestating sows' feces. However, no effects were observed in colostrum, milk, or lactating sows' feces. Dietary n-3 LCFA modified the microbiota composition of gestating sows' feces, milk, and suckling piglets' feces, without affecting lactating sows' feces or colostrum. In gestating sows' feces and milk, the decrease in genus Succinivibrio and the increase of Proteobacteria phylum, due to the increased genera Brenneria and Escherichia, respectively, stand out. In the feces of suckling piglets, the higher abundance of the beneficial genus Akkermansia and Bacteroides, and different species of Lactobacillus are highlighted. In addition, positive correlations for families and genera were found between lactating sows' feces and milk, milk and suckling piglets' feces, and lactating sows' feces and suckling piglets' feces. To conclude, dietary n-3 LCFA had a positive impact on the microbiome of suckling piglet's feces by increasing microbial diversity and some beneficial bacteria populations, had a few minor modifications on the microbiome of milk and gestating sows' feces and did not change the microbiome in lactating sows' feces or colostrum. Therefore, this study shows the effect of dietary n-3 LCFA on the microbiota of sows, colostrum, milk, and suckling piglets during the lactation period providing crucial information on the microbiota status at the early stages of life, which have an impact on the post-weaning.

Development of Intestinal Injury and Restoration of Weaned Piglets under Chronic Immune Stress

This study aimed to investigate the effects of lipopolysaccharide (LPS)-induced chronic immune stress on intestinal morphology and function, immune system, oxidative status, and mitochondrial function in piglets. Fifty healthy Duroc × Landrace × Yorkshire piglets (21 ± 2 days old, barrow, 6.98 ± 0.14 kg body weight) were selected and randomly allotted to five groups, which were slaughtered at 0 (0 group), 1, 5, 9, and 15 d of LPS injection. The results showed that compared with the piglets without LPS injection, LPS injection significantly impaired the intestinal morphology and permeability at 1, 5, and 9 d, as manifested by the increased serum lactic acid and decreased ratio of villus height to crypt depth (p < 0.05). Moreover, intestinal inflammation and oxidative and mitochondrial injury were caused at 1 d, as manifested by upregulated IL-6 mRNA expression, increased malondialdehyde content, and impaired mitochondrial morphology (p < 0.05). However, these parameters were restored to levels identical to 0 group at 9~15 d, accompanied by significantly increased antioxidant capacity, enhanced protein expression of CD3+ and CD68+, and upregulated mRNA abundance of genes related to mitochondrial biogenesis and functions (p < 0.05). Collectively, these results suggest that the intestinal injury of piglets caused by chronic immune stress could be self-repaired.

Morphological Assessment and Biomarkers of Low-Grade, Chronic Intestinal Inflammation in Production Animals

Simple Summary

Production animals are continuously exposed to environmental and dietary factors that might induce a state of low-grade, chronic intestinal inflammation. This condition compromises the productive performance and well-fare of these animals, requiring studies to understand what causes it and to develop control strategies. An intestinal inflammatory process is generally associated with alterations in the structure and functionality of its wall, resulting in the release of cellular components into the blood and/or feces. These components can act as biomarkers, i.e., they are measured to identify and quantify an inflammatory process without requiring invasive methods. In this review we discuss the mechanisms of low-grade inflammation, its effects on animal production and sustainability, and the identification of biomarkers that could provide early diagnosis of this process and support studies of useful interventional strategies.

Abstract

The complex interaction between the intestinal mucosa, the gut microbiota, and the diet balances the host physiological homeostasis and is fundamental for the maximal genetic potential of production animals. However, factors such as chemical and physical characteristics of the diet and/or environmental stressors can continuously affect this balance, potentially inducing a state of chronic low-grade inflammation in the gut, where inflammatory parameters are present and demanding energy, but not in enough intensity to provoke clinical manifestations. It’s vital to expand the understanding of inflammation dynamics and of how they compromise the function activity and microscopic morphology of the intestinal mucosa. These morphometric alterations are associated with the release of structural and functional cellular components into the feces and the blood stream creating measurable biomarkers to track this condition. Moreover, the identification of novel, immunometabolic biomarkers can provide dynamic and predictors of low-grade chronic inflammation, but also provide indicators of successful nutritional or feed additive intervention strategies. The objective of this paper is to review the mechanisms of low-grade inflammation, its effects on animal production and sustainability, and the biomarkers that could provide early diagnosis of this process and support studies of useful interventional strategies.

Weaning Stress in Piglets Alters the Expression of Intestinal Proteins Involved in Fat Absorption

BACKGROUND

In vivo data on intestinal fat absorption in weanling piglets are scarce.

OBJECTIVES

This study aimed to investigate the effect of weaning stress on intestinal fat absorption.

METHODS

Eighteen 7-d-old sow-reared piglets (Duroc-Landrace-Yorkshire) were assigned to 3 groups (n = 6/group, 3 males and 3 females per group). Piglets were nursed by sows until 24 d of age (suckling piglets, S), or weaned at 21 d of age to a corn-soybean meal-based diet until 24 d (3 d postweaning, W3) or 28 d (7 d postweaning, W7) of age, respectively. Duodenum, jejunum, and ileum were collected to determine intestinal morphology and abundance of proteins related to fat absorption.

RESULTS

Compared with the S group, the W3 group had lower villus height (17-34%) and villus height to crypt depth ratio (13-53%), as well as 1-1.45 times greater crypt depth; these values were 1.18-1.31, 0.69-1.15, and 1.47-1.87 times greater in the W7 group than in the W3 group, respectively. Compared with the S group, weaning stress for both W3 and W7 groups reduced intestinal alkaline phosphatase activity (26-73%), serum lipids (26-54%), and abundances of proteins related to fatty acid transport [fatty acid transport protein 4 (FATP4) and intestinal fatty acid-binding protein (I-FABP)] and chylomicron assembly [microsomal triglyceride transfer protein (MTTP), apolipoprotein A-IV (APOA4), B (APOB), and A-I (APOA1)] in the duodenum and ileum (10-55%), as well as in the jejunum (25-85%). All these indexes did not differ between W3 and W7 groups. Compared with the S group, the W3 group had lower mRNA abundances of duodenal APOA4 and APOA1 (25-50%), as well as jejunal FATP4, IFABP, MTTP, APOA4, and APOA1 (35-50%); these values were 5-15% and 10-37% lower in the W7 group than in the W3 group, respectively.

CONCLUSIONS

Weaning stress in piglets attenuates the expression of intestinal proteins related to fatty acid transport (FATP4 and I-FABP) and chylomicron synthesis (APOA4).

Changes Induced by Aging and Long-Term Exercise and/or DHA Supplementation in Muscle of Obese Female Mice

Obesity and aging promote chronic low-grade systemic inflammation. The aim of the study was to analyze the effects of long-term physical exercise and/or omega-3 fatty acid Docosahexaenoic acid (DHA) supplementation on genes or proteins related to muscle metabolism, inflammation, muscle damage/regeneration and myokine expression in aged and obese mice. Two-month-old C57BL/6J female mice received a control or a high-fat diet for 4 months. Then, the diet-induced obese (DIO) mice were distributed into four groups: DIO, DIO + DHA, DIO + EX (treadmill training) and DIO + DHA + EX up to 18 months. Mice fed a control diet were sacrificed at 2, 6 and 18 months. Aging increased the mRNA expression of Tnf-α and decreased the expression of genes related to glucose uptake (Glut1, Glut4), muscle atrophy (Murf1, Atrogin-1, Cas-9) and myokines (Metrnl, Il-6). In aged DIO mice, exercise restored several of these changes. It increased the expression of genes related to glucose uptake (Glut1, Glut4), fatty acid oxidation (Cpt1b, Acox), myokine expression (Fndc5, Il-6) and protein turnover, decreased Tnf-α expression and increased p-AKT/AKT ratio. No additional effects were observed when combining exercise and DHA. These data suggest the effectiveness of long-term training to prevent the deleterious effects of aging and obesity on muscle dysfunction.

Tannic acid-chelated zinc supplementation alleviates intestinal injury in piglets challenged by porcine epidemic diarrhea virus

Porcine epidemic diarrhea virus (PEDV) has become a challenging problem in pig industry all over the world, causing significant profit losses. Tannins and organic zinc have been shown to exert protective effects on the intestinal dysfunction caused by endotoxins. However, there is little information on tannic acid-chelated zinc (TAZ) supplementation in the diet of newborn piglets. This study was conducted to determine the effects of TAZ on the intestinal function of piglets infected with PEDV. Thirty-two 7-day-old piglets were randomly allocated to 1 of 4 treatments in a 2 × 2 factorial design consisting of 2 diets (0 or 50 mg/kg BW TAZ) and challenge (saline or PEDV). On day 9 of the trial, 8 pigs per treatment received either sterile saline or PEDV solution at 10⁶ TCID₅₀ (50% tissue culture infectious dose) per pig. Pigs infected with PEDV had greater diarrhea rate and lower average daily gain (ADG) (P < 0.05). PEDV infection decreased plasma D-xylose concentration, most antioxidative enzyme activities in plasma and intestine, as well as the small intestinal villus height (P < 0.05). Plasma diamine oxidase and blood parameters were also affected by PEDV infection. Dietary supplementation with TAZ could ameliorate the PEDV-induced changes in all measured variables (P < 0.05). Moreover, TAZ decreased the concentration of malondialdehyde in plasma, duodenum, jejunum, and colon (P < 0.05). Collectively, our results indicated that dietary TAZ could alleviate PEDV induced damage on intestinal mucosa and antioxidative capacity, and improve the absorptive function and growth in piglets. Therefore, our novel findings also suggest that TAZ, as a new feed additive for neonatal and weaning piglets, has the potential to be an alternative to ZnO.

Necroptosis Contributes to LPS-Induced Activation of the Hypothalamic-Pituitary-Adrenal Axis in a Piglet Model

Stressors cause activation of the hypothalamic-pituitary-adrenal (HPA) axis and a systemic inflammatory response. As a newly proposed cell death manner in recent years, necroptosis occurs in a variety of tissue damage and inflammation. However, the role of necroptosis in HPA axis activation remains to be elucidated. The aim of this study was to investigate the occurrence of necroptosis and its role in HPA activation in a porcine stress model induced by Escherichia coli lipopolysaccharide (LPS). Several typical stress behaviors like fever, anorexia, shivering and vomiting were observed in piglets after LPS injection. HPA axis was activated as shown by increased plasma cortisol concentration and mRNA expression of pituitary corticotropin-releasing hormone receptor 1 (CRHR1) and adrenal steroidogenic acute regulatory protein (StAR). The mRNA expression of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 in the hypothalamus, pituitary gland and adrenal gland was elevated by LPS, accompanied by the activation of necroptosis indicated by higher mRNA expression of necroptosis signals including receptor-interacting protein kinase (RIP) 1, RIP3, and phosphorylated mixed-lineage kinase domain-like protein (MLKL). Furthermore, necrostatin-1 (Nec-1), an inhibitor of necroptosis, inhibited necroptosis indicated by decreased mRNA levels of RIP1, RIP3, MLKL, and phosphoglycerate mutase family member 5 (PGAM5) in the hypothalamus, pituitary gland and adrenal gland. Nec-1 also decreased the mRNA expression of TNF-α and IL-β and inhibited the activation of the HPA axis indicated by lower plasma cortisol concentration and mRNA expression of adrenal type 2 melanocortin receptor (MC2R) and StAR. These findings suggest that necroptosis is present and contributes to HPA axis activation induced by LPS. These findings provide a potential possibility for necroptosis as an intervention target for alleviating HPA axis activation and stress responses.

Long-chain PUFA ameliorate enterotoxigenic Escherichia coli-induced intestinal inflammation and cell injury by modulating pyroptosis and necroptosis signaling pathways in porcine intestinal epithelial cells

This study was aimed to investigate whether EPA and arachidonic acid (ARA), the representative n-3 or n-6 PUFA, could alleviate enterotoxigenic Escherichia coli (ETEC) K88-induced inflammation and injury of intestinal porcine epithelial cells 1 (IPEC-1) by modulating pyroptosis and necroptosis signalling pathways. IPEC-1 cells were cultured with or without EPA or ARA in the presence or absence of ETEC K88. EPA and ARA reduced ETEC K88 adhesion and endotoxin content in the supernatant. EPA and ARA increased transepithelial electrical resistance, decreased permeability of fluorescein isothiocyanate-labelled dextran, increased membrane protein expression of occludin, ZO-1 and claudin-1 and relieved disturbed distribution of these proteins. EPA and ARA also reduced cell necrosis ratio. EPA or ARA reduced mRNA and concentration of TNF-α, IL-6 and IL-8 and decreased mRNA abundances of intestinal toll-like receptors 4 and its downstream signals. Moreover, EPA and ARA downregulated mRNA expression of nod-like receptor protein 3 (NLRP3), caspase 1 and IL-18 and inhibited protein expression of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), gasdermin D and caspase-1. Finally, EPA and ARA reduced mRNA expression of fas-associated death domain protein, caspase 8, receptor-interacting protein kinase (RIP) 1, mixed lineage kinase-like protein (MLKL), phosphoglycerate mutase 5 (PGAM5), motility-related protein 1 (Drp1) and high mobility protein 1 (HMGB1) and inhibited protein expression of phosphorylated-RIP1, p-RIP3, p-MLKL and HMGB1. These data demonstrate that EPA and ARA prevent ETEC K88-induced cell inflammation and injury, which is partly through inhibiting pyroptosis and necroptosis signalling pathways.

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.

Phytogenic feed additives alleviate pathogenic Escherichia coli-induced intestinal damage through improving barrier integrity and inhibiting inflammation in weaned pigs

Background

This study was conducted to investigate the effects of each phytogenic feed additive (PFA; PFA1, bitter citrus extract; PFA2, a microencapsulated blend of thymol and carvacrol; PFA3, a mixture of bitter citrus extract, thymol, and carvacrol; PFA4, a premixture of grape seed, grape marc extract, green tea, and hops; PFA5, fenugreek seed powder) on the growth performance, nutrient digestibility, intestinal morphology, and immune response in weaned pigs infected with Escherichia coli (E. coli).

Results

A total of 63 4-week-old weaned pigs were placed in individual metabolic cages and assigned to seven treatment groups. The seven treatments were as follows: 1) NC; basal diet without E. coli challenge, 2) PC; basal diet with E. coli challenge, 3) T1; PC + 0.04% PFA1, 4) T2; PC + 0.01% PFA2, 5) T3; PC + 0.10% PFA3, 6) T4; PC + 0.04% PFA4, 7) T5; PC + 0.10% PFA5. The experiments lasted in 21 d, including 7 d before and 14 d after the first E. coli challenge. In the E. coli challenge treatments, all pigs were orally inoculated by dividing a total of 10 mL of E. coli F18 for 3 consecutive days. The PFA-added groups significantly increased (P < 0.05) average daily gain and feed efficiency and decreased (P < 0.05) the fecal score at d 0 to 14 post-inoculation (PI). Tumor necrosis factor α was significantly lower (P < 0.05) in the PFA-added groups except for T1 in d 14 PI compared to the PC treatment. The T3 had a higher (P < 0.05) immunoglobulin G and immunoglobulin A concentration compared to the PC treatment at d 7 PI. Also, T3 showed significantly higher (P < 0.05) villus height:crypt depth and claudin 1 expression in ileal mucosa, and significantly down-regulated (P < 0.05) the expression of calprotectin compared to the PC treatment.

Conclusions

Supplementation of PFA in weaned pigs challenged with E. coli alleviated the negative effects of E. coli and improved growth performance. Among them, the mixed additive of bitter citrus extract, thymol, and carvacrol showed the most effective results, improving immune response, intestinal morphology, and expression of tight junctions.

The Role of Diet in Regulation of Macrophages Functioning

The great importance of diet for health and high life-expectancy is established. The impact of nutrients on immune system is a point of growing research interest. Recent studies have found pro- and anti-inflammatory properties of some diet patterns and nutrients that can be used from the bench to the bedside for chronic low-grade inflammatory status correction. In this regard, the assessment of potential effects of nutrition on macrophage differentiation, proliferation, and functioning in health and disease is highly demanded. In this review, we present current data on the effects of nutrients on the macrophage functioning.

Effects of Artemisia argyi Powder on Egg Quality, Antioxidant Capacity, and Intestinal Development of Roman Laying Hens

This study was conducted to evaluate the effect of dietary supplementation with Artemisia argyi (A. argyi) on egg quality, serum biochemical, antioxidant capacity, and intestinal development in Roman laying hens. A total of 432 (34-week-old) Roman hens were randomly divided into control group and three experimental groups. The control group was fed a basal diet, and the experimental group was fed a basal diet with 1%, 2%, and 3% A. argyi powder, respectively. The results showed that dietary supplementation of 2% A. argyi to the diet increased egg weight and egg white weight, and the daturic acid (C17:0), stearic acid (C18:0), eicosadienoic acid (C20:2), docosahexaenoic acid (C22:6n-3), α-linolenic acid (C18:3n-3), linoleic acid (C18:2n-6c), and polyunsaturated fatty acid (PUFA) in egg yolk. Meanwhile, the addition of 1∼3% A. argyi decreased serum urea. Moreover, dietary supplementation of 1% A. argyi promoted the antioxidative capacity of the hens by increasing hepatic T-SOD and CAT activities, as well as GSH-Px content. However, the addition of 3% A. argyi to the diet significantly increased the content of malondialdehyde in serum and liver and destroyed the intestinal morphology by increasing duodenal crypt depth. In conclusion, the addition level of A. argyi promoting egg quality and antioxidant capacity was at 2% and 1%, respectively.

Effects of TolC on the pathogenicity of porcine extraintestinal pathogenic Escherichia coli

Extraintestinal pathogenic Escherichia coli (ExPEC) is a well-known critical pathogenic zoonosis that causes extraintestinal infections in humans and animals by affecting their immune organs. Recently, research on the outer membrane protein of E. coli, tolerant colicin (TolC), a virulent protein in the formation of the ExPEC efflux pump, has been an attractive subject. However, the pathogenic mechanisms remain unclear. This study aimed to explore the role of TolC in the pathogenesis of the ExPEC strain PPECC42; a complementation strain (Cm-TolC) and an isogenic mutant (ΔTolC) were constructed. Loss of TolC drastically impaired the virulence of ExPEC in an experimental mouse model. ΔTolC showed a substantial decrease in the porcine aortic vascular endothelial cell (PAVEC) adherence, invasion, and pro-inflammatory response, in contrast to that of the wild type, with a reduced survival ratio in both the bacterial load and whole blood in mice. ΔTolC also showed decreased expression of necroptosis signals such as receptor-interacting protein kinase 1, phosphorylated mixed-lineage kinase domain-like protein, and mitochondrial proteins such as phosphoglycerate mutase family member 5. Our data suggest that TolC is closely associated with ExPEC pathogenesis. These results provide scientific grounds for exploring the potential of TolC as an effective drug target for controlling ExPEC infection, screening new inhibitors, and developing new drugs. This will allow for further prevention and control of ExPEC infection.

Selenium-enriched Cardamine violifolia improves growth performance with potential regulation of intestinal health and antioxidant function in weaned pigs

This study was conducted to evaluate the effects of different Selenium (Se) sources on growth performance, intestinal function and antioxidant status of weaned piglets. A total of 300 weaned pigs were randomly allocated to 5 treatment groups with 5 replicates of 12 pigs/pen. The control group was corn-soybean basal diet without any additional Se supplement. The experimental diets were supplemented with 0.3 mg/kg of Se from sodium selenite (SS), Se-enriched yeast (SEY), Se-enriched Cardamine violifolia (SEC) and 0.3+0.3 mg/kg of Se from SEY and SEC, respectively. The trial lasted for 4 weeks. The results showed that diets supplementation with SEY, SEC or SEY+SEC could improve average daily gain and reduce feed/gain ratio during the entire study. Compared with the control group, SEC or SEY+SEC improved intestinal morphology, indicated by greater villus height and villus height/ crypt depth ratio. In addition, SEC or SEY+SEC also increased maltase and lactase activities as well as tight junction protein expression. Different Se sources decreased malondialdehyde (MDA) concentration and improved superoxide dismutase (SOD) activity in serum. In the jejunum, SEY or SEC reduced MDA concentration and increased total antioxidant capacity (T-AOC) compared with the control group. Moreover, SEY+SEC increased the antioxidant parameters including SOD and T-AOC in the jejunum. Dietary SEY or SEC supplementation significantly increased the mRNA expression of selenoproteins including thioredoxin reductase 1 (TXNRD1), selenoprotein I (SELENOI), selenoprotein S (SELENOS), and selenoprotein P (SELENOP) in the jejunum. In conclusion, organic Se sources, especially Cardamine violifolia, improve growth performance, potentially by regulating intestinal function, antioxidant capacity and selenoprotein expression in piglets.

EPA and DHA confer protection against deoxynivalenol-induced endoplasmic reticulum stress and iron imbalance in IPEC-1 cells

This study assessed the molecular mechanism of EPA or DHA protection against intestinal porcine epithelial cell line 1 (IPEC-1) cell damage induced by deoxynivalenol (DON). The cells were divided into six groups, including the CON group, the EPA group, the DHA group, the DON group, the EPA + DON group and the DHA + DON group. RNA sequencing was used to investigate the potential mechanism, and qRT-PCR was employed to verify the expression of selected genes. Changes in ultrastructure were used to estimate pathological changes and endoplasmic reticulum (ER) injury in IPEC-1 cells. Transferrin receptor 1 (TFR1) was tested by ELISA. Fe²⁺ and malondialdehyde (MDA) contents were estimated by spectrophotometry, and reactive oxygen species (ROS) was assayed by fluorospectrophotometry. RNA sequencing analysis showed that EPA and DHA had a significant effect on the expression of genes involved in ER stress and iron balance during DON-induced cell injury. The results showed that DON increased ER damage, the content of MDA and ROS, the ratio of X-box binding protein 1s (XBP-1s)/X-box binding protein 1u (XBP-1u), the concentration of Fe²⁺ and the activity of TFR1. However, the results also showed that EPA and DHA decreased the ratio of XBP-1s/XBP-1u to relieve DON-induced ER damage of IPEC-1 cells. Moreover, EPA and DHA (especially DHA) reversed the factors related to iron balance. It can be concluded that EPA and DHA reversed IPEC-1 cell damage induced by DON. DHA has the potential to protect IPEC-1 cells from DON-induced iron imbalance by inhibiting ER stress.

Pectin supplementation ameliorates intestinal epithelial barrier function damage by modulating intestinal microbiota in lipopolysaccharide-challenged piglets

During weaning, infants and young animals are susceptible to severe enteric infections, thus inducing intestinal microbiota dysbiosis, intestinal inflammation, and impaired intestinal barrier function. Pectin (PEC), a prebiotic polysaccharide, enhances intestinal health with the potential for therapeutic effect on intestinal diseases. One 21-days study was conducted to investigate the protective effect of pectin against intestinal injury induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) in a piglet model. A total of 24 piglets (6.77±0.92 kg BW; Duroc × Landrace × Large White; barrows; 21 d of age) were randomly assigned into three groups: control group, LPS-challenged group, and PEC + LPS group. Piglets were administrated with LPS or saline on d14 and d21 of the experiment. All piglets were slaughtered and intestinal samples were collected after 3 h administration on d21. Pectin supplementation ameliorated the LPS-induced inflammation response and damage to the ileal morphology. Meanwhile, pectin also improved intestinal mucin barrier function, increased the mRNA expression of MUC2, and improved intestinal mucus glycosylation. LPS challenge reduced the diversity of intestinal microbiota and enriched the relative abundance of Helicobacter. Pectin restored alpha diversity improved the structure of the gut microbiota by enriching anti-inflammatory bacteria and short-chain fatty acid (SCFA)-producing bacteria, and increased the concentrations of acetate. In addition, Spearman rank correlation analysis also revealed the potential relationship between intestinal microbiota and intestinal morphology, intestinal inflammation, and intestinal glycosylation in piglets. Taken together, these results indicate that pectin enhances intestinal integrity and barrier function by altering intestinal microbiota composition and their metabolites, which subsequently alleviates intestinal injury and finally improves the growth performance of piglets.

Stimbiotic Supplementation Alleviates Poor Performance and Gut Integrity in Weaned Piglets Induced by Challenge with E. coli

The aim of this study was to investigate the effects of stimbiotic (STB), a xylanase and xylo-oligosaccharide complex. A total of 36 male weaned pigs with initial body weights of 8.49 ± 0.10 kg were used in a 3-week experiment. The experiment was conducted in a 2 × 3 factorial arrangement (six replicates/treatment) of treatments consisting of two levels of challenge (challenge and non-challenge) and three levels of STB (0, 0.5, and 1 g/kg diet). Supplementations STB 0.5 g/kg (STB5) and STB 1 g/kg (STB10) improved the G:F (p = 0.04) in piglets challenged with STEC. STB supplementation, which also decreased (p < 0.05) the white blood cells, neutrophils, lymphocytes, and expression levels of tumor necrosis factor-alpha and interleukin-6. Supplementations STB5 and STB10 improved (p < 0.01) the lymphocytes and neutrophils in piglets challenged with STEC on 14 dpi. Additionally, supplementations STB5 and STB10 improved (p < 0.01) the tumor necrosis factor-alpha in piglets challenged with STEC on 3 dpi. Supplementations STB5 and STB10 also improved the villus height-to-crypt depth ratio (p < 0.01) in piglets challenged with STEC. Supplementation with STB reduced (p < 0.05) the expression levels of calprotectin. In conclusion, STB could alleviate a decrease of the performance, immune response, and inflammatory response induced by the STEC challenge.