Early Weaning Stress in Pigs Impairs Innate Mucosal Immune Responses to Enterotoxigenic E. coli Challenge and Exacerbates Intestinal Injury and Clinical Disease (original) (raw)

Weaning causes a prolonged but transient change in immune gene expression in the intestine of piglets

Journal of Animal Science, 2021

Controlling gut inflammation is important in managing gut disorders in the piglet after weaning. Establishing patterns of inflammation markers in the time subsequent to weaning is important for future research to determine whether interventions are effective in controlling gut inflammation. The objective of this study was to evaluate the intestinal inflammatory response during the postweaning period in piglets. A 45-d study included 108 piglets (weaned at 22 d, body weight 5.53 ± 1.19 kg), distributed in 12 pens with nine pigs per pen. Histomorphometry, gene expression of pro- and anti-inflammatory cytokines, and the quantity of immunoglobulin (Ig) A producing cells were measured in jejunum, ileum, and colon on days 0, 15, 30, and 45 postweaning. Cytokine gene expression in peripheral blood mononuclear cells and Ig quantities were analyzed in blood from piglets on days 0, 15, 30, and 45 postweaning. Histomorphometrical results showed a lower villus length directly after weaning. Res...

Stress signaling pathways activated by weaning mediate intestinal dysfunction in the pig

American Journal of Physiology-Gastrointestinal and Liver Physiology, 2006

Weaning in the piglet is a stressful event associated with gastrointestinal disorders and increased disease susceptibility. Although stress is thought to play a role in postweaning intestinal disease, the mechanisms by which stress influences intestinal pathophysiology in the weaned pig are not understood. The objectives of these experiments were to investigate the impact of weaning on gastrointestinal health in the pig and to assess the role of stress signaling pathways in this response. Nineteen-day-old pigs were weaned, and mucosal barrier function and ion transport were assessed in jejunal and colonic tissues mounted on Ussing chambers. Weaning caused marked disturbances in intestinal barrier function, as demonstrated by significant ( P < 0.01) reductions in transepithelial electrical resistance and increases in intestinal permeability to [3H]mannitol in both the jejunum and colon compared with intestinal tissues from age-matched, unweaned control pigs. Weaned intestinal tiss...

Gut response induced by weaning in piglet features marked changes in immune and inflammatory response

At weaning, piglets are exposed to many stressors, such as separation from the sow, mixing with other litters, end of lactational immunity, and a change in their environment and gut microbiota. The sudden change of feeding regime after weaning causes morphological and histological changes in the small intestine which are critical for the immature digestive system. Sixteen female piglets were studied to assess the effect of sorbic acid supplementation on the small intestine tissue transcriptome. At weaning day (T0, piglet age 28 days), four piglets were sacrificed and ileal tissue samples collected. The remaining 12 piglets were weighed and randomly assigned to different postweaning (T5, piglet age 33 days) diets. Diet A (n=6) contained 5 g/kg of sorbic acid. In diet B (n=6), the organic acids were replaced by barley flour. Total RNA was isolated and then hybridized to CombiMatrix CustomArray™ 90-K platform microarrays, screening about 30 K genes. Even though diet had no detectable effect on the transcriptome during the first 5 days after weaning, results highlighted some of the response mechanisms to the stress of weaning occurring in the piglet gut. A total of 205 differentially expressed genes were used for functional analysis using the bioinformatics tools BLAST2GO, Ingenuity Pathway Analysis 8.0, and Dynamic Impact Approach (DIA). Bioinformatic analysis revealed that apoptosis, RIG-I-like, and NOD-like receptor signaling were altered as a result of weaning. Interferons and caspases gene families were the most activated after weaning in response to piglets to multiple stressors. Results suggest that immune and inflammatory responses were activated and likely are a cause of small intestine atrophy as revealed by a decrease in villus height and villus/crypt ratio.

Postnatal development of intestinal immune system in piglets: implications for the process of weaning

Animal Research, 2004

European-wide directives are in place to establish a sustainable production of pigs without using production enhancers and chemotherapeutics. Thus, an economically-viable pig production is now only possible when the physiological mechanisms of defense against pathogens and tolerance against nutrients and commensal bacteria in the intestinal immune system are taken into account. During the postnatal period the piglet is facing first the time large amounts of new antigens and at weaning a second wave of nutritional antigens is entering the intestinal tract. The appropriate development of humoral and cellular functions of the intestinal immune system is essential for optimum growth and performance of the piglets. The integrity of the intestinal surfaces is a prerequisite of intestinal immunity and tolerance. Secretory IgA serves to exclude harmful antigens from uptake. The induction of intestinal immune reactions starts with antigen presentation by professional antigen presenting cells of Peyer's patches and mesenteric lymph nodes. In addition, the intestinal lamina propria serves as a mucosal compartment for regulation of immune responses. Here especially T regulatory cells (CD4 + CD25 + ) have their function for maintaining intestinal homeostasis. The network of mucosal T and B cells develops after birth in a programmed sequence; it is almost completed at week 7 after birth. Weaning is associated with changes in the regulation of the lymphoid cells in the mucosa. In small and large intestine increases in pro-and anti-inflammatory cytokines were observed after weaning in lymphocytes. Epithelial cells were studied both in intestinal samples and in vitro.

Enterococcus faecium NCIMB 10415 supplementation affects intestinal immune-associated gene expression in post-weaning piglets

Veterinary Immunology and Immunopathology, 2014

In a Salmonella challenge study of weaned piglets supplemented with the probiotic Enterococcus faecium NCIMB 10415 (SF68), we observed a delayed, post-infection proliferative response of purified blood mononuclear cell fractions towards Salmonella antigens. In order to clarify this observation, we examined the patterns of immune-associated gene expression in long-term feeding trials of both pre-and post-weaning piglets. Piglets supplemented with E. faecium NCIMB 10415 showed a post-weaning dysregulation in the expression patterns of both pro-and anti-inflammatory cytokine expression in intestinal tissues and spleen. Piglets of the supplemented group showed significantly reduced levels of IL-8, IL-10 and the co-stimulatory molecule CD86 mRNA expression in ileal Peyer's patches. The expression of CTLA4, an inhibitor of T-cell activation/proliferation, showed similar levels of expression in all tissues examined, particularly in ileal Peyer's patches post-weaning where IL-8, IL-10 and CD86 transcript levels were significantly reduced relative to control animals. Blood serum cytokine protein levels showed elevated TGF␤ in pre-weaning piglets which, together with IL-6, may have suppressed IFN␥ production in the probiotic-fed animals. In a second Salmonella challenge study, post-weaning, E. faecium-fed animals showed significantly elevated levels of IL-8 gene expression in mesenteric lymph nodes, but reduced levels in the spleen. At early times post-infection, the probiotic-fed group showed similar levels of IL-10, CD86 and CTLA4 mRNA expression as the control animals in intestinal Peyer's Patches, despite high relative levels of IL-8 expression in mesenteric lymph nodes. The sum of the observations suggests that supplementation of pre-weaning piglets with E. faecium affects intestinal immune-associated gene expression, which is aggravated postweaning when the animals receive increased levels of the probiotic in feed. We suggest the post-weaning reductions in gene expression may delay the host response to infections, and provide pathogenic bacteria such as Salmonella with a "window of opportunity", leading to the increased bacterial loads and shedding observed in challenge trials. Possible mechanisms explaining these effects of E. faecium NCIMB 10415 are discussed. G Model VETIMM-9120; No. of Pages 13 2 B. Siepert et al. / Veterinary Immunology and Immunopathology xxx (2013) xxx-xxx

Effect of chronic and acute enterotoxigenic E. coli challenge on growth performance, intestinal inflammation, microbiome, and metabolome of weaned piglets

Scientific Reports, 2022

Post-weaning enteropathies in swine caused by pathogenic E. coli, such as post-weaning diarrhea (PWD) or edema disease (ED), remain a significant problem for the swine industry. Reduction in the use of antibiotics over concerns of antibiotic resistance and public health concerns, necessitate the evaluation of effective antibiotic alternatives to prevent significant loss of livestock and/or reductions in swine growth performance. For this purpose, an appropriate piglet model of pathogenic E. coli enteropathy is required. In this study, we attempted to induce clinical signs of post-weaning disease in a piglet model using a one-time acute or lower daily chronic dose of a pathogenic E. coli strain containing genes for both heat stable and labile toxins, as well as Shiga toxin. The induced disease state was monitored by determining fecal shedding and colonization of the challenge strain, animal growth performance, cytokine levels, fecal calprotectin, histology, fecal metabolomics, and fe...

Diet-dependent Mucosal Colonization and Interleukin-1β Responses in Preterm Pigs Susceptible to Necrotizing Enterocolitis

Journal of Pediatric Gastroenterology & Nutrition, 2009

Objectives: Intestinal colonization challenges the neonatal innate immune system, especially in newborns with an immature immune response lacking the supportive bioactive components from mother's milk. Accordingly, formula-fed preterm pigs frequently show bacterial overgrowth, mucosal atrophy, and gut lesions reflecting necrotizing enterocolitis (NEC) within the first days after birth. We hypothesized that NEC development is related to a diet-dependent bacterial adherence and a subsequent proinflammatory cytokine response in the gut mucosa immediately after introduction of enteral food. Materials and Methods: Premature piglets (92% gestation) received 2 to 3 days of total parenteral nutrition followed by 0, 8, or 17 hours of enteral formula or sow's colostrum feeding. Results: Following 8 hours, but not 17 hours, of colostrum feeding, a reduced number of intestinal samples with adherent bacteria (both Gram-negative and Gram-positive bacteria) was counted compared with 0 or 8 hours of formula feeding. Besides a more dense colonization, formula feeding leads to higher intestinal interleukin-1b (IL-1b) levels and more NEC-like lesions from 8 hours onward. The load of adherent bacteria was especially high in NEC lesions. Toll-like receptor 4 was detected in enteroendocrine, neuronal, and smooth muscle cells, potentially mediating the increase in IL-1b levels by Gram-negative bacteria. Conclusions: Formula feeding facilitates bacterial adherence and the development of a proinflammatory state of the intestine, which may be among the key factors that predispose formulafed preterm neonates to NEC. JPGN 49:90-98, 2009.

Weaning anorexia may contribute to local inflammation in the piglet small intestine

The Journal of nutrition, 1999

Compromising alterations in villus-crypt structure are common in pigs postweaning. Possible contributions of local inflammatory reactions to villus-crypt alterations during the weaning transition have not been described. This study evaluated local inflammatory responses and their relationship with morphological changes in the intestine in 21-d-old pigs (n = 112) killed either at weaning (Day 0) or 0.5, 1, 2, 4 or 7 d after weaning to either milk- or soy-based pelleted diets. Cumulative intake averaged <100 g during the first 2 d postweaning, regardless of diet. During this period of weaning anorexia, inflammatory T-cell numbers and local expression of the matrix metalloproteinase stromelysin increased while jejunal villus height, crypt depth and major histocompatibility complex (MHC) class I RNA expression decreased. Upon resumption of feed intake by the fourth d postweaning, villus height and crypt depth, CD8(+) T cell numbers, MHC class I RNA expression and local expression of ...

Plasma metabolomic profiles and immune responses of piglets after weaning and challenge with E. coli

Journal of Animal Science and Biotechnology, 2014

Background: The processes of weaning and exposure to pathogenic bacteria induce stress responses, which may alter the metabolism. In this study, we investigated the changes in plasma metabolites and immune responses in piglets in response to the stress induced by weaning and Escherichia coli challenge. Results: Fecal dry matter decreased (P = 0.003) and nearly half (44.4%) the piglets developed diarrhea on day 2 and 3 postweaning. The concentration of plasma immunoglobulin A was higher (P < 0.001) on day 11 postweaning than on day 0 or 4 postweaning. The levels of white blood cells increased continuously (P < 0.001) from day 0 to day 11 postweaning. Differences in the percentages of neutrophils (P = 0.029) and lymphocytes (P = 0.022) were seen, but the neutrophil/lymphocyte ratio did not differ in the period after weaning. A clear separation of the metabolomic profile data for day 0 and day 4 postweaning was observed with a principal components analysis (PCA) scores plot, and the data for day 11 were located between those for day 0 and day 4 postweaning. The plasma levels of proline, taurine, and carnitine were higher, whereas those of betaine, creatine, L-arginine and acetylcarnitine were lower on day 4 postweaning than on day 0. Levels of lysophosphatidylcholine and phosphatidylcholine were either higher or lower after weaning, depending on the chain lengths or characters of these metabolites. Conclusions: Our results show a clear separation in the plasma metabolomic profiles of piglets that corresponded to the fecal responses to stress on the piglets induced by weaning or exposure to a pathogen (E. coli). These plasma metabolite profiles suggest that the challenges induced proinflammatory responses in the piglets, resulting in postweaning diarrhea, which was associated with higher concentrations of IgA in the plasma.

Total parenteral nutrition alters molecular and cellular indices of intestinal inflammation in neonatal piglets

Journal of Parenteral and Enteral Nutrition, 1999

Background: The adverse effects of TPN on systemic immunity are well-documented; however, the impact of IV feeding on neonatal intestinal immunity is unknown. Methods: A piglet TPN model was used to compare immune cell composition within the intestinal epithelium and lamina propria of parenterally and orally fed piglets. Results: Small intestinal weight of piglets maintained intravenously was reduced 50% after 7 days. Intestinal atrophy in piglets fed parenterally was evidenced by decreased width of intestinal villi and colon cuffs and reduced intestinal crypt depth. The numbers of CD4 + and CD8 + T lymphocytes were threefold greater within the lamina propria of jejunal and ileal villi of piglets supported intravenously. Inverse correlations were