Effects of dietary fibres on gut microbial metabolites and liver lipid metabolism in growing pigs

J Anim Physiol Anim Nutr (Berl). 2020 Sep;104(5):1484-1493. doi: 10.1111/jpn.13429. Epub 2020 Aug 1.

Abstract

This study was conducted to investigate the effects of dietary supplementation with wheat bran fibre, inulin and their combination on growth performance, short-chain fatty acids (SCFAs) production in caecum and colon and liver lipid metabolism in growing pigs. A total of 48 Duroc × Landrace × Yorkshire cross-bred growing pigs (73 ± 2 days of age; 24.37 ± 2.86 kg) were allocated to four groups randomly, each group consisting of six pens with two pigs each. The pigs were fed a control diet (CON), a diet containing 2% wheat bran fibre (WB), a diet containing 2% inulin (IN), and a diet containing both of 1% wheat bran fibre and 1% inulin (MIX), respectively. The trial lasted for 28 days. The results showed that MIX fed pigs had a higher percentage of fat in the liver than those fed the CON (p < .05). IN, WB or MIX feeding decreased the concentrations of acetate and total SCFAs in colon compared with CON (p < .01). Feeding WB or IN also decreased the colonic butyrate concentrations compared with CON (p < .01). However, the serum level of valeric acid was elevated in the IN, WB and MIX group (p < .01). MIX fed pigs tended to have lower levels of propionate in serum than the WB fed pigs (p = .098). MIX feeding enhanced the mRNA expression of lipid synthesis-related genes in liver compared with CON (p < .05). Feeding IN decreased the expression of bile acids synthesis-related genes in liver and increased mRNA expression of SCFAs transporter SLC16A1 in colon compared with CON (p < .05). In this study, these data indicated that the combined supplementation of wheat bran fibre and inulin decreased the SCFAs concentrations in the colon, enhanced the genes FAS and HNF-4α mRNA expression in liver and induced liver lipid accumulation in growing pigs.

Keywords: bile acids; dietary fibre; hepatic lipids; inulin; short-chain fatty acids.

MeSH terms

  • Animals
  • Colon / drug effects
  • Colon / metabolism
  • Dietary Fiber / administration & dosage*
  • Fatty Acids, Volatile
  • Gastrointestinal Microbiome / drug effects*
  • Gastrointestinal Microbiome / physiology
  • Gene Expression Regulation / drug effects
  • Lipid Metabolism / drug effects*
  • Liver / drug effects*
  • Liver / metabolism
  • Swine / metabolism*
  • Swine / microbiology
  • Transcriptome

Substances

  • Dietary Fiber
  • Fatty Acids, Volatile