Historically, Ezekiel bread is a fasting food used in biblical days during times of hardship. It is made of wheat, barley, broad beans, lentils, millet and spelt, and it would last for days in the desert. It certainly wasn't glamorous, and the taste may not have been wonderful, but it was food. Personally, I love the taste.
Ezekiel bread recipes use spouted grains, which help release all the energy from the bread's assorted grains, making it easier to digest. It is a highly nutritious bread and something to consider for adding fiber and protein to your diet.
Currently, there are numerous commercial varieties available to you. You can also find an excellent Ezekiel bread recipe in the The Eat-Clean Diet® Cookbook.