One way to look at this is to remember that mold is one of the most prevalent organisms in our environments - it is present in our food, in the air, and on living surfaces. Therefore, we are all ingesting small amounts of mold from time to time without any harmful effect.
Furthermore, the body has multiple defense mechanisms to protect against any organisms that we ingest. In the case of mold, it is almost certainly instantly destroyed when it comes into contact with the acid produced in the stomach.
Therefore, in short, having accidentally consumed some moldy bread shouldn't have any harmful health effect. The most likely consequence from eating moldy bread is simply the unpleasant experience of realizing that you just did it!
That being said, if you experience any concerning symptoms like nausea, abdominal pain
, vomiting, or diarrhea, or fever
, or cough you should be checked out by your primary care doctor
. They will be able to make sure everything is ok and that you did not pick up any serious infection. Again, this is extremely unlikely to occur after eating the common types of molds that are found in bread, and I wouldn't worry about it too much.