Effects of galacto-oligosaccharides on growth and gut function of newborn suckling piglets

Abstract

Background: Most research on galacto-oligosaccharides (GOS) has mainly focused on their prebiotic effects on the hindgut, but their beneficial effects on the small intestine (SI) have received little attention. Since jejunum is the important place to digest and absorb nutrients efficiently, optimal maturation of the jejunum is necessary for maintaining the high growth rate in the neonate. Therefore, this study investigates the effect of the early intervention with GOS on the intestinal development of the jejunum. Methods: A total of 6 litters of neonatal piglets (10 piglets per litter; Duroc × Landrace × Large White) with an average birth weight of 1.55±0.05kg received 1 of 2 treatments based on their assignment to either the control (CON) group or the GOS (GOS) group in each litter. Piglets in the GOS group were orally administrated 10mL of a GOS solution (reaching 1g GOS/kg body weight) per day from the age of 1 to 7 d; the piglets in the CON group were treated with the same dose of physiological saline. All piglets were weaned on d 21. On d 8 and 21 of the experimental trial, 1 pig per group from each of the 6 litters was euthanized. Results: The early intervention with GOS increased the average daily gains in the third week (P<0.05). Decreased crypt depth was also observed in the jejunum of the piglets on d 21 (P<0.05). The early intervention with GOS increased the jejunal lactase activity on d 8, maltase activity and sucrase activity on d 21 (P<0.05). In addition, the early intervention with GOS also facilitated the mRNA expression of Sodium glucose co-transporter 1 (SGLT1) on d 8 and the mRNA expression of Glucose transporter type 2 (GLUT2) on d 21 (P<0.05). It was further determined that GOS up-regulated the mRNA expression of preproglucagon (GCG), insulin-like growth factor 1 (IGF-1), insulin-like growth factor 1 receptor (IGF-1R) and epidermal growth factor (EGF). GOS also up-regulated the protein expression of glucagon-like peptide-2 (GLP-2) and EGF in the jejunum of the piglets. Furthermore, it was also found that GOS enhanced the protein expression of ZO-1 and occludin on d 8 (P<0.05), as well as increased the mRNA expression of TGF-β and decrease the mRNA expression of IL-12 (P<0.05). Conclusions: These results indicate that GOS have a positive effect on piglet growth performance in addition to decreasing the crypt depth and enhancing functional development in jejunum of suckling piglets.