Dietary l-threonine supplementation attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage of broiler chickens at an early age

Br J Nutr. 2018 Jun;119(11):1254-1262. doi: 10.1017/S0007114518000740.


This study was conducted to investigate the protective effects of l-threonine (l-Thr) supplementation on growth performance, inflammatory responses and intestinal barrier function of young broilers challenged with lipopolysaccharide (LPS). A total of 144 1-d-old male chicks were allocated to one of three treatments: non-challenged broilers fed a basal diet (control group), LPS-challenged broilers fed a basal diet without l-Thr supplementation and LPS-challenged broilers fed a basal diet supplemented with 3·0 g/kg l-Thr. LPS challenge was performed intraperitoneally at 17, 19 and 21 d of age, whereas the control group received physiological saline injection. Compared with the control group, LPS challenge impaired growth performance of broilers, and l-Thr administration reversed LPS-induced increase in feed/gain ratio. LPS challenge elevated blood cell counts related to inflammation, and pro-inflammatory cytokine concentrations in serum (IL-1β and TNF-α), spleen (IL-1β and TNF-α) and intestinal mucosa (jejunal interferon-γ (IFN-γ) and ileal IL-1β). The concentrations of intestinal cytokines in LPS-challenged broilers were reduced by l-Thr supplementation. LPS administration increased circulating d-lactic acid concentration, whereas it reduced villus height, the ratio between villus height and crypt depth and goblet density in both jejunum and ileum. LPS-induced decreases in jejunal villus height, intestinal villus height:crypt depth ratio and ileal goblet cell density were reversed with l-Thr supplementation. Similarly, LPS-induced alterations in the intestinal mRNA abundances of genes related to intestinal inflammation and barrier function (jejunal toll-like receptor 4, IFN- γ and claudin-3, and ileal IL-1 β and zonula occludens-1) were normalised with l-Thr administration. It can be concluded that l-Thr supplementation could attenuate LPS-induced inflammatory responses and intestinal barrier damage of young broilers.

Keywords: l-Threonine; l-thr l-threonine; ADFI average daily feed intake; ADG average daily gain; CLDN claudin; D-LA d-lactic acid; DAO diamine oxidase; F:G feed:gain ratio; IFN-γ interferon-γ; LPS lipopolysaccharide; MUC2 mucin 2; MyD88 myeloid differentiation factor 88; NRC National Research Council; OCLN occludin; TFF2 trefoil factor 2; TLR4 toll-like receptor 4; ZO-1 zonula occludens-1; Broilers; Inflammatory responses; Intestinal barriers; Lipopolysaccharides.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed / analysis
  • Animals
  • Chickens*
  • Diet / veterinary
  • Dietary Supplements
  • Gene Expression Regulation / drug effects
  • Inflammation / chemically induced
  • Inflammation / prevention & control
  • Inflammation / veterinary*
  • Intestinal Mucosa
  • Intestines / drug effects*
  • Intestines / pathology
  • Lipopolysaccharides / toxicity*
  • Male
  • Poultry Diseases / chemically induced*
  • Poultry Diseases / prevention & control
  • Threonine / administration & dosage*


  • Lipopolysaccharides
  • Threonine