For what it's worth, here's a study.

Do fruit flies carry any diseases? Fruit flies do not carry infectious agents on the inside of their bodies. They are not disease vectors. However, they can carry bacteria on the outside of their bodies and transmit them by contact with fruits or vegetables, which can cause disease when consumed.

Is it safe to eat food that has been touched by fruit flies? No, it is not safe. If food was touched by fruit flies, there may be bacteria that cause disease. The appropriate strategy is to remove the damaged area of the food or to dispose of it.

Can fruit flies be harmful to humans? Fruit flies are not harmful to humans. They do not bite or sting. They also don't have venom. However, when fruit flies wound ripe fruit or vegetables to lay eggs, bacteria can enter the food, and when humans consume it, they can get a disease.

What happens if you eat a fruit fly? There is no scientific evidence of diseases caused by eating a fruit fly. Also, there is no scientific evidence that eating the fruit fly's eggs can cause disease.