The "do" in this sentence is unnecessary. "How many people receive bread from these (not theses) bakeries" is how you would write this sentence.
Generally, the auxiliary verb "do" is not included in sentences of this structure unless you are trying to affirm something or answer a question.
Examples of this would be:
Person 1: "I don't think you run"
Person 2: "I do run. I really do."
Person 1: "Do you run?"
Person 2: "I do run."
Other than these situations, when using an action verb in a present tense declarative sentence, you should leave off the "do".
Hope this helped :)