Grind the oatmeal finely in a blender.
In a bowl, mix the oat flour, baking powder, and salt.
In another bowl, combine the egg, milk, and oligosaccharide, mixing well.
Combine the dry and wet ingredients to make the dough.
Add the blueberries and gently mix.
Divide the batter into muffin cups.
Bake in a preheated oven at 180°C (356°F) for 20 minutes.