Transglycosylated Starch Improves Insulin Response and Alters Lipid and Amino Acid Metabolome in a Growing Pig Model

Abstract

Due to the functional properties and physiological effects often associated with chemically modified starches, significant interest lies in their development for incorporation in processed foods. This study investigated the effect of transglycosylated cornstarch (TGS) on blood glucose, insulin, and serum metabolome in the pre- and postprandial phase in growing pigs. Eight jugular vein-catheterized barrows were fed two diets containing 72% purified starch (waxy cornstarch (CON) or TGS). A meal tolerance test (MTT) was performed with serial blood sampling for glucose, insulin, lipids, and metabolome profiling. TGS-fed pigs had reduced postprandial insulin (p < 0.05) and glucose (p < 0.10) peaks compared to CON-fed pigs. The MTT showed increased (p < 0.05) serum urea with TGS-fed pigs compared to CON, indicative of increased protein catabolism. Metabolome profiling showed reduced (p < 0.05) amino acids such as alanine and glutamine with TGS, suggesting increased gluconeogenesis compared to CON, probably due to a reduction in available glucose. Of all metabolites affected by dietary treatment, alkyl-acyl-phosphatidylcholines and sphingomyelins were generally increased (p < 0.05) preprandially, whereas diacyl-phosphatidylcholines and lysophosphatidylcholines were decreased (p < 0.05) postprandially in TGS-fed pigs compared to CON. In conclusion, TGS led to changes in postprandial insulin and glucose metabolism, which may have caused the alterations in serum amino acid and phospholipid metabolome profiles.

Keywords: insulin; meal tolerance test; metabolite profiles; metabolome; modified starch; pig model.

Figure 1

Insulin (A); glucose (B); lactate (C); and urea (D) in blood serum or plasma from pigs fed control (CON) or transglycosylated starch (TGS) diet. Data are presented as least square means; control diet n = 6, TGS diet n = 7. ** CON and TGS diet differ in blood serum or plasma concentrations, p < 0.05; * CON and TGS diet tend to differ in blood serum or plasma concentrations, 0.05 < p ≤ 0.10.

Figure 2

Triglycerides (A); non-esterified fatty acids (NEFA; B); cholesterol (C); total short-chain fatty acids (SCFA; D); acetate (E); and propionate (F) concentrations in blood serum from pigs fed control (CON) or transglycosylated starch (TGS) diet. Data are presented as least square means; control diet n = 6, TGS diet n = 7. ** CON and TGS diet differ in blood serum or plasma concentrations, p < 0.05; * CON and TGS diet tend to differ in blood serum or plasma concentrations, 0.05 < p ≤ 0.10.