Place lentils, pinto beans, white beans, great Northern beans, and red beans into a large container and cover with several inches of cool water; let soak 8 hours to overnight.
Drain lentils, pinto beans, white beans, Northern beans, and red beans; combine in a large pot. Add 1 cup warm water; bring to a boil. Reduce heat to medium; cook until tender, adding more water if needed, about 45 minutes. Cool to room temperature.
Dissolve 1 tablespoon honey, 2 cups bread flour, and 2 packages yeast in 2 cups warm water in a bowl to make the starter.
Mix wheat germ, wheat and barley cereal, flax seeds, spelt, oat bran, oats, and millet together in a bowl. Add 2 cups warm water, 2 packages yeast, and 1 1/4 cups all-purpose flour; stir until well combined.
Puree bean mixture in a food processor; transfer to the bowl of a stand mixer fitted with a dough hook. Add the starter and wheat germ mixture; mix. Add the 1 cup water, remaining honey, canola oil, sugar, and salt; mix to combine. Add the remaining 1 3/4 cups all-purpose flour in batches, mixing thoroughly after each addition; stir until no dry spots remain.
Turn dough out onto a lightly floured surface; knead until smooth and elastic, about 8 minutes. Place in a large, lightly-oiled bowl; turn to coat. Cover with a towel; let rise in a warm place until doubled in size, about 1 hour.
Grease 3 large loaf pans. Divide dough equally and place into the prepared pans. Cover and let rise until doubled in volume, about 40 minutes.
Preheat oven to 350 degrees F (175 degrees C).
Bake in the preheated oven until golden brown, about 45 minutes.
Remove loaves from pans and return to oven, placed upside-down on the bare oven rack. Continue baking until bottoms are browned, about 5 minutes. Remove from oven; let cool.
