In a small bowl add the wheat bran and skim milk and set aside.
Mix the flours, oat bran, flax seed, baking powder and baking soda and set aside. Preheat oven to 400F. Fill muffins pans with 16 muffins liners.
In a large bowl add the bananas and mash with a potato masher. Then add in the egg, brown sugar, canola and sour cream. Mix well with a wooden spoon. Add in the flour mixture and the bran mixture into the bowl and stir to combine. Don't overmix. Fold in the blueberries.
Fill the muffin cups to almost full and bake for 20 min or until they spring back when touched in the middle and are golden brown. Let cool in the muffin tin for 5 min. and then remove to cool completely on a wire rack.
Store in an airtight container for up to 5 days or freeze.