Dietary fiber alters immunity and intestinal barrier function of different breeds of growing pigs

Front Immunol. 2023 Feb 14:14:1104837. doi: 10.3389/fimmu.2023.1104837. eCollection 2023.

Abstract

Introduction: Dietary fiber (DF) regulates immune response and barrier function by interacting with epithelial cells and immune cells. However, the differences in the regulation of intestinal health of different pig breeds by DF remain obscure.

Methods: A total of 60 healthy pigs (20 pigs/breed) from Taoyuan black (TB), Xiangcun black (XB), and Duroc (DR) pigs (body weight = 11.00 ± 1.00 kg) were fed two different levels (low and high) of DF for 28 days to evaluate the differences in the modulation of intestinal immunity and barrier function by DF in different pig breeds.

Results: TB and XB pigs had higher plasma Eos level, Eos%, and Lym% but lower Neu level compared with the DR pigs when fed low DF (LDF). The TB and XB pigs had higher plasma Eos, MCV, and MCH levels and Eos% while lower Neu% compared with the DR pigs when fed high DF (HDF). HDF decreased IgA, IgG, IgM, and sIgA concentrations in the ileum of TB and XB pigs compared with the DR pigs, while the plasma IgG and IgM concentrations of TB pigs were higher than those of the DR pigs. Moreover, compared with the DR pigs, HDF decreased the levels of IL-1β, IL-17, and TGF-β in the plasma, and IL-1β, IL-2, IL-6, IL-10, IL-17, IFN-γ, TGF-β, and TNF-α in the ileum of TB and XB pigs. However, HDF did not affect the mRNA expression of cytokines in the ileum of TB, XB, and DR pigs, while HDF increased the TRAF6 expression of TB pigs compared with the DR pigs. In addition, HDF increased the Claudin abundance of TB and DR pigs compared with the pigs feeding with LDF. Moreover, in the LDF and HDF groups, the XB pigs had higher protein abundances of Claudin and ZO-1 compared with the TB and DR pigs.

Conclusions: DF regulated the TB and DR pigs' plasma immune cells, the XB pigs showed enhanced barrier function, and the DR pigs had increased ileal inflammation, which indicates that Chinese indigenous pigs are more DF tolerant than the DR pigs.

Keywords: Chinese indigenous pig; Duroc pig; dietary fiber; immune function; intestinal barrier function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Claudins
  • Diet* / veterinary
  • Dietary Fiber*
  • Immunoglobulin G
  • Immunoglobulin M
  • Interleukin-17
  • Intestines* / physiology
  • Swine

Substances

  • Claudins
  • Dietary Fiber
  • Immunoglobulin G
  • Immunoglobulin M
  • Interleukin-17

Grants and funding

This work was jointly supported by the Key Project of Regional Innovation and Development Joint Fund of National Natural Science Foundation of China (U20A2056), Youth Foundation of Guangxi Natural Science Foundation (2021JJB130431), Open Foundation of the Key Laboratory of Agro-Ecological Processes in Subtropical Region, Chinese Academy of Sciences (ISA2022105), and Special Funds for Construction of Innovative Provinces in Hunan Province (2019RS3022).