title: Impact of dietary organic acids and botanicals on intestinal integrity and inflammation in weaned pigs.
abstract: BACKGROUND
  Organic acids, such as citric and sorbic acid, and pure plant-derived constituents, like monoterpens and aldehydes, have a long history of use in pig feeding as alternatives to antibiotic growth promoters. However, their effects on the intestinal barrier function and inflammation have never been investigated. Therefore, aim of this study was to assess the impact of a microencapsulated mixture of citric acid and sorbic acid (OA) and pure botanicals, namely thymol and vanillin, (PB) on the intestinal integrity and functionality of weaned pigs and in vitro on Caco-2 cells. In the first study 20 piglets were divided in 2 groups and received either a basal diet or the basal diet supplemented with OA + PB (5 g/kg) for 2 weeks post-weaning at the end of which ileum and jejunum samples were collected for Ussing chambers analysis of trans-epithelial electrical resistance (TER), intermittent short-circuit current (I SC), and dextran flux. Scrapings of ileum mucosa were also collected for cytokine analysis (n = 6). In the second study we measured the effect of these compounds directly on TER and permeability of Caco-2 monolayers treated with either 0.2 or 1 g/l of OA + PB.
  
  
  RESULTS
  Pigs fed with OA + PB tended to have reduced I SC in the ileum (P = 0.07) and the ileal gene expression of IL-12, TGF-β, and IL-6 was down regulated. In the in vitro study on Caco-2 cells, TER was increased by the supplementation of 0.2 g/l at 4, 6, and 14 days of the experiment, whereas 1 g/l increased TER at 10 and 12 days of treatment (P < 0.05). Dextran flux was not significantly affected though a decrease was observed at 7 and 14 days (P = 0.10 and P = 0.09, respectively).
  
  
  CONCLUSIONS
  Overall, considering the results from both experiments, OA + PB improved the maturation of the intestinal mucosa by modulating the local and systemic inflammatory pressure ultimately resulting in a less permeable intestine, and eventually improving the growth of piglets prematurely weaned.
authors.affiliation: DIMEVET, University of Bologna, Ozzano Emilia, 40064, Bologna, Italy. ester.grilli@unibo.it.
authors.forename: Ester
authors.initials: E
authors.lastname: Grilli
authors.affiliation: DIMEVET, University of Bologna, Ozzano Emilia, 40064, Bologna, Italy. benedetta.tugnoli2@unibo.it.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Tugnoli
authors.affiliation: University of Surrey, Guildford, Surrey, GU2 7XH, UK. jadelpassey1@gmail.com.|North Carolina State University, Department of Population Health and Pathobiology, Raleigh, NC, 27695, USA. jadelpassey1@gmail.com.
authors.forename: Jade L
authors.initials: JL
authors.lastname: Passey
authors.affiliation: Laboratory of Developmental Nutrition, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, NC, 27695, USA. chstahl@ncsu.edu.
authors.forename: Chad H
authors.initials: CH
authors.lastname: Stahl
authors.affiliation: DIMEVET, University of Bologna, Ozzano Emilia, 40064, Bologna, Italy. andrea.piva@unibo.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Piva
authors.affiliation: North Carolina State University, Department of Population Health and Pathobiology, Raleigh, NC, 27695, USA. ajmoeser@ncsu.edu.|Center for Comparative Medicine and Translational Research (CCMTR), North Carolina State University, College of Veterinary Medicine, Raleigh, NC, 27695, USA. ajmoeser@ncsu.edu.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Moeser
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001547:Benzaldehydes / Q000008:administration & dosage / Q000494:pharmacology*; D018938:Caco-2 Cells; D019343:Citric Acid / Q000008:administration & dosage / Q000494:pharmacology*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007249:Inflammation / Q000517:prevention & control / Q000662:veterinary*; D007422:Intestines / Q000187:drug effects; D013011:Sorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D013552:Swine; D013943:Thymol / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D001547:Benzaldehydes; D016207:Cytokines; D019343:Citric Acid; D013943:Thymol; C100058:vanillin; D013011:Sorbic Acid