Diets containing different
starch types affect peripheral
glucose and
insulin responses. However, the role of
starch chemistry in kinetics of nutrient absorption and
insulin and
incretin secretion is poorly understood. Four portal vein-catheterized pigs (35.0 ± 0.2 kg
body weight) consumed 4 diets containing 70% purified
starch [0-63.2%
amylose content and 0.22 (slowly) to 1.06%/min (rapidly) maximum rate of in vitro digestion] for 7-d periods in a 4 × 4 Latin square. On d 7, blood was collected for 12 h postprandial with simultaneous blood flow measurement for determining the net portal appearance (NPA) of nutrients and
hormones. The NPA of
glucose,
insulin,
C-peptide, and
glucose-dependent insulinotropic
polypeptide (GIP) during 0-4 h postprandial were lower (P < 0.05) and those of
butyrate and total SCFA were higher (P < 0.05) when pigs consumed the diet containing slowly digestible compared with rapidly digestible
starch. The peak NPA of
insulin occurred prior to that of
glucose when pigs consumed diets containing rapidly digestible
starch. The kinetics of insulin secretion had a linear positive relation with kinetics of NPA of
glucose (R(2) = 0.50; P < 0.01). In conclusion,
starch with high
amylose and low in vitro digestibility decreases the kinetics of
glucose absorption and
insulin and GIP secretion and increases SCFA absorption and
glucagon-like peptide-1 secretion. In conclusion,
starch with high
amylose content and a lower rate and extent of in vitro digestion decreased
glucose absorption and insulin secretion and increased SCFA absorption.