Both the salivary glands and pancreas produce amylase, but in different isoforms. Salivary amylase is ptyalin, coded by the AMY1 gene. Pancreatic amylase is c

Both the salivary glands and pancreas produce amylase, but in different isoforms. Salivary amylase is ptyalin, coded by the AMY1 gene. Pancreatic amylase is coded by AMY2. Humans have multiple copies of these genes, and more copies means more amylase is produced. Someone with 4 copies of AMY1 can still digest starch, but someone with 16 copies of AMY1 might have most of their eaten starches reduced to oligosaccharides long before their ptyalin is inactivated in the stomach. More copies of AMY1 is directly correlated to historic populations with higher starch consumption. Gut biota will also make their own amylases. An amylase blocker causes carbohydrate malabsorption, and that is about the same as a lactose-intolerant person consuming lactose. The starches end up getting fermented in the intestine. The gut biota will consume most of them, but I suppose it is possible they might drop some on the floor for the intestine to absorb. My hypothesis is that the slower rate of digestion of starch produces a lesser effect on perceived satiety.