Combine flour, wheat bran, oats, baking soda, baking powder, brown sugar, salt and wheat germ in a bowl. Stir well with a whisk. Slowly add buttermilk until just moist. Set aside for 15 minutes.
Spoon batter into a 9 X 5-inch metal loaf pan that has been coated with non-stick cooking spray. Bake at 400° F for 40 minutes or until a wooden toothpick inserted in center comes out clean. Let cool in pan for 5 minutes on a wire rack; remove from pan. Cool completely on rack.