Most rabbits love bread because it is high in carbohydrates. However it is not good for them and can cause diarrhea. If you feed your rabbits bread then limit it to a very small amount as an occasional treat.
The diet of rabbits should be based upon pellets that are balanced and designed to meet their nutritional needs according to their age. For example, baby rabbits cannot digest starch very well (the reason why they shouldn't eat bread) but they digest fat really well (similar to their mamma's milk). For this reason baby rabbit food should be low in starch and high in fat, balanced with quality protein and fortified with natural vitamins and chelated minerals. It is also very important that it contains a lot of fiber and is made primarily upon hay.
Adult rabbits do best eating a grain-free and soy-free diet fortified with the same vitamins and minerals. This style of diet will keep them looking healthy and feeling great... and even more playful.
So, can rabbits eat bread? Yes they can but they shouldn't!