Response to weaning and dietary l-glutamine supplementation: metabolomic analysis in piglets by gas chromatography/mass spectrometry

Abstract

A novel metabolomic method based on gas chromatography/mass spectrometry (GC-MS) was applied to determine the metabolites in the serum of piglets in response to weaning and dietary L-glutamine (Gln) supplementation. Thirty-six 21-d-old piglets were randomly assigned into three groups. One group continued to suckle from the sows (suckling group), whereas the other two groups were weaned and their diets were supplemented with 1% (w/w) Gln or isonitrogenous L-alanine, respectively, representing Gln group or control group. Serum samples were collected to characterize metabolites after a 7-d treatment. Results showed that twenty metabolites were down-regulated significantly (P<0.05) in control piglets compared with suckling ones. These data demonstrated that early weaning causes a wide range of metabolic changes across arginine and proline metabolism, aminosugar and nucleotide metabolism, galactose metabolism, glycerophospholipid metabolism, biosynthesis of unsaturated fatty acid, and fatty acid metabolism. Dietary Gln supplementation increased the levels of creatinine, D-xylose, 2-hydroxybutyric acid, palmitelaidic acid, and α-L-galactofuranose (P<0.05) in early weaned piglets, and were involved in the arginine and proline metabolism, carbohydrate metabolism, and fatty acid metabolism. A leave-one-out cross-validation of random forest analysis indicated that creatinine was the most important metabolite among the three groups. Notably, the concentration of creatinine in control piglets was decreased (P=0.00001) compared to the suckling piglets, and increased (P=0.0003) in Gln-supplemented piglets. A correlation network for weaned and suckling piglets revealed that early weaning changed the metabolic pathways, leading to the abnormality of carbohydrate metabolism, amino acid metabolism, and lipid metabolism, which could be partially improved by dietary Gln supplementation. These findings provide fresh insight into the complex metabolic changes in response to early weaning and dietary Gln supplementation in piglets.

Relative bioavailability ofl-lysine sulfate is equivalent to that ofl-lysine HCl for nursery piglets1

“…Creatinine has been related to muscular mass (Deguchi 1997) and its levels associated with the quality of dietary protein (Awosanya et al, 1999). Moreover, increased in serum levels of creatinine was observed with dietary l-glutamine supplementation in weaned piglets (Xiao et al, 2012). The results of this study indicate that creatinine is not a suitable indicator of the amino acid utilization of the diet.…”

Weaning Stress Perturbs Gut Microbiome and Its Metabolic Profile in Piglets

“…During a short period after weaning, small intestine length, microvilli height, crypt depth, and barrier function of piglets were changed. What’s more, digestive enzyme activity and absorptive capacity of small intestine were reduced, resulting in a low absorption capacity of amino acids and carbohydrates 31 . In the present study, decreased essential amino acids such as valine and some carbohydrate in weaned piglets supported this view.…”

Serum Amino Acids Profile and the Beneficial Effects of L-Arginine or L-Glutamine Supplementation in Dextran Sulfate Sodium Colitis

“…Metabolically, arginine or glutamine supplementation causes remarkably change of serum profile of amino acids at day 7 and 12. The explanation for this change is that arginine or glutamine supplementation will change carbohydrate metabolism, amino acid metabolism, and lipid metabolism, leading to the change of serum profile of amino acids [26] – [28] . Intriguingly, dietary arginine or glutamine supplementation significantly increases serum Gln content and AAI, which are lowered in our DSS-induced colitis model.…”