Sodium butyrate administration improves intestinal development of suckling lambs

Abstract

This study was conducted to investigate the effects of sodium butyrate (SB) supplementation on growth performance, intestinal barrier functions, and intestinal bacterial communities in sucking lambs. Forty lambs of 7 d old, with an average body weight (BW) of 4.46 ± 0.45 kg, were allocated into the control (CON) or SB group, with each group having five replicate pens (n = 5). Lambs were orally administered SB at 1.8 mL/kg BW in the SB group or the same volume of saline in the CON group. Treatments were administered from 7 to 35 d of age, when one lamb from each replicate was slaughtered to obtain intestinal tissues and contents. The results showed that supplementation with SB tended to increase the BW (P = 0.079) and the starter intake (P = 0.089) of lambs at 35 d of age. The average daily gain of lambs in the SB group was significantly greater than that in the CON group (P < 0.05). The villus height of jejunum in the SB group was markedly higher (P < 0.05) than that in the CON group. In ileum, lambs in the SB group had lower (P < 0.05) crypt depth and greater (P < 0.05) villus-to-crypt ratio than those in the CON group. Compared with the CON group, the mRNA and protein expressions of Claudin-1 and Occludin were increased (P < 0.05) in the SB group. Supplementation with SB decreased the relative abundances of pathogenic bacteria, including Clostridia_UCG-014 (P = 0.094) and Romboutsia (P < 0.05), which were negatively associated with the intestinal barrier function genes (P < 0.05). The relative abundance of Succiniclasticum (P < 0.05) was higher in the SB group, and it was positively correlated with the ratio of villi height to crypt depth in the jejunum (P < 0.05). Compared with the CON group, the function "Metabolism of Cofactors and Vitamins" was increased in the SB group lambs (P < 0.05). In conclusion, SB orally administration during suckling period could improve the small intestine development and growth performance of lambs by inhibiting the harmful bacteria (Clostridia_UCG-014, Romboutsia) colonization, and enhancing intestinal barrier functions.

Keywords: intestinal barrier; intestinal microbiota; sodium butyrate; suckling lambs.

Figure 1.

Animal and experimental design. ^* Four lambs, born on the same day and with similar BW, were placed and housed in one pen, which was considered an experimental replicate. Thus, there were five replicates in each treatment (n = 5). ^ɤ The SB powder was dissolved in saline at a concentration of 0.2 g/mL, the administrated amount was adjusted weekly according to the BW. ^# One lamb of each replicate in the two groups was randomly selected for slaughter. CON, control, SB, sodium butyrate

Figure 2.

Effect of sodium butyrate supplementation on growth performance of suckling lambs. (A) Body weight (BW), (B) Starter intake, (C) Average daily gain (ADG). CON, control; SB, sodium butyrate.

Figure 3.

The intestinal morphology of the duodenum, jejunum, and ileum. The black line means the villus height. CON, control; SB, sodium butyrate.

Figure 4.

Effect of sodium butyrate supplementation on the relative mRNA and protein expressions of tight junction protein in the jejunum. (A) Claudin-1 mRNA expression; (B) Occludin mRNA expression; (C) Relative protein level of Claudin-1; (D) Relative protein level of Claudin-1. * P < 0.05; ** P < 0.01.

Figure 5.

Number of operational taxonomic units (OTUs) in two groups. (A) Rarefaction curves of OTUs; (B) Venn diagram of shared OTUs; (C) Principal coordinate analysis (PCoA) based on Weighted UniFrac distance. CON, control; SB, sodium butyrate.

Figure 6.

Jejunal bacterial community composition of suckling lamb. Abundances of the jejunal microbiota at the (A) phylum and (C) genus levels of lamb. The top 10 phyla and the top 20 genera are listed. Comparisons of relative abundances at the phylum (B) and genus (D) levels were analyzed by the Kruskal–Wallis rank-sum test. CON, control; SB, sodium butyrate.

Figure 7.

Linear discriminant analysis effect size analysis identified the most differentially abundant jejunal microbiota between CON and SB groups. Taxa with LDA score greater than three are shown in the histogram. CON, control; SB, sodium butyrate.

Figure 8.

The relative abundance (A) and significant difference (B) in predicted metabolism pathways (KEGG) between the CON and SB groups from the jejunum using PIURUSt. CON, control; SB, sodium butyrate.

Figure 9.

Pearson’s correlation coefficients for individual major jejunal bacterial genera and phenotypic variables. Value represents the correlation coefficient, with positive value representing a positive correlation and negative value denoting a negative correlation. * P < 0.05.

Figure 10.

Graphical summary of the effect of sodium butyrate administration on the intestinal development and health of suckling lambs. Sodium butyrate oral delivery inhibited harmful bacteria colonization, enhanced intestinal barrier functions, and consequently improved intestinal development and growth performance of suckling lambs.