1/4 cup wheat germ has the same amount of fibre as 1/4 cup whole wheat flour, and twice as much fibre as the same amount of white flour. While it has 3x as much fat (1.5 g compared to .5 g) it has less than half the calories, a third fewer carbohydrates, and as much protein.
Consider that 1/4 wheat germ weighs about half as much as 1/4 cup of all-purpose white or whole wheat flour. This means that you can effectively take out 1/4 cup of flour and add 1/2 cup of wheat germ, giving you 4x as much fibre as white flour alone without altering the texture of your quick breads or making them too heavy.
If you have a kitchen scale, you can substitute wheat germ by weight: simply measure the flour and weigh it, then remove 1/4 or 1/2 cup of flour and add wheat germ to make up the weight. I recommend starting with 1/2 cup wheat germ for 1/4 cup flour. I've had good results with that amount.