As noted in the last post, insects live in close contact with many pathogens. The presence of antibiotic substances in insects is not uncommon. Insects that feed on dead or dying tissue often must compete with microbes for the food resource.
Blow fly maggots consume dead and dying tissue. The maggots will only feed on dead or dying tissue and leave healthy tissue. They also secrete antibiotic substances that inhibit microbes from colonizing and consuming their food. There are intractable cases where maggot debridement therapy is useful for treating wounds. Diabetics are more prone to problems with wounds that do not heal. Festering wounds may become gangrenous and lead to amputation.
The video below documents a successful use of maggots to treat a wound in a diabetic who was facing amputation of a foot because of a wound that would not heal. The maggots used in this therapy are produced in licensed laboratories under sterile conditions. It is important to not introduce additional pathogens into an already infected wound. The maggots are sealed onto the wound site with a bandage. They consume the dead and dying tissue and leave the healthy tissue.
Maggot therapy is important to human health, but not for the squeamish.