Yeast is an ingredient that is used in many recipes. Yeast grows quickly when sugar is added to it. That is why people will add dry active yeast to their breads. Usually sugar is added to the bread even if it is a small amount. This allows the bread to rise.
So, if you eat bread or drink alcohol, you have actually consumed yeast. However, it was cooked. Therefore, eating the yeast in chocolate bread is fine. Yeast is in many foods that people eat. If you ate dry active yeast without cooking it, it would not kill you. However, your stomach would most likely hurt afterwards. Your stomach would fill up and you would feel bloated as a result.